Jugant S, Regnier A, Douet JY.To evaluate the safety and effectiveness of diamond burr debridement (DBD) for the treatment of calcific band keratopathy (CBK) in horses. Methods: Medical records from horses with CBK were reviewed over a period of 4 years. Diagnosis of CBK was based on slit-lamp examination findings, and DBD was performed on standing sedated horses. Follow-up was obtained by clinical reevaluation of the treated eyes or a telephone survey with the referring veterinarian. Results: Twenty-two horses of different ages (median: 11 years; range: 5-23) representing 24 CBK-affected eyes (14 left eyes and 10 righ...
Ku00f6ninger M, von Velsen-Zerweck A, Eiberger C, Lu00f6ffler C, Tu00f6pper A, Visscher C, Reckels B, Vervuert I.The aim of this study was to examine the nutrient composition and feed hygiene of alfalfa as well as investigate the feed intake, blood, urine and faecal parameters of horses fed alfalfa haylage (AS) compared with alfalfa hay (AH) and meadow hay (MH). A total of 11 geldings were fed ad libitum (2.1% dry matter (DM) of body weight (BW)) with alfalfa haylage, alfalfa hay and meadow hay (MH) in a Latin square design. On days 0 and 21 of the feeding period, blood samples were analysed for kidney and liver parameters. Faecal samples were analysed for pH, DM and short-chain fatty acids (SCFAs). Spon...
Dube F, Delhomme N, Martin F, Hinas A, u00c5brink M, Svu00e4rd S, Tydu00e9n E.Anthelmintic resistance in equine parasite Parascaris univalens, compromises ivermectin (IVM) effectiveness and necessitates an in-depth understanding of its resistance mechanisms. Most research, primarily focused on holistic gene expression analyses, may overlook vital tissue-specific responses and often limit the scope of novel genes. This study leveraged gene co-expression network analysis to elucidate tissue-specific transcriptional responses and to identify core genes implicated in the IVM response in P. univalens. Adult worms (n = 28) were exposed to 10-11 M and 10-9 M IVM in vitro for 2...
Ren W, Wang J, Zeng Y, Wang T, Meng J, Yao X.The Kazakh horse, renowned for its excellence as a breed, exhibits distinctive reproductive traits characterized by early maturity and seasonal estrus. While normal reproductive function is crucial for ensuring the breeding and expansion of the Kazakh horse population, a noteworthy decline in reproductive capabilities is observed after reaching 14 years of age. Unassigned: In this study, ovarian granulosa cells (GCs) were meticulously collected from Kazakh horses aged 1, 2, 7, and above 15 years old (excluding 15 years old) for whole transcriptome sequencing. Unassigned: The analysis identifie...
Miglio A, Falcinelli E, Cappelli K, Mecocci S, Mezzasoma AM, Antognoni MT, Gresele P.Training has a significant effect on the physiology of blood coagulation in humans and in horses. Several hemostatic changes have been reported after exercise in the horse but data available are inconclusive. The aim of this study was to investigate platelet activation and primary platelet-related hemostasis modifications in young never-trained Thoroughbreds in the first incremental training period in order to improve knowledge on this topic. Twenty-nine clinically healthy, untrained, 2-year-old Thoroughbred racehorses were followed during their incremental 4-month sprint exercise training. Bl...
Lapsina S, Stirn M, Hofmann-Lehmann R, Schoster A, Riond B.Acidification of equine urine to promote dissociation of ion complexes is a common practice for urine ion concentration measurements. The objective of this study was to evaluate the effect of acidification and storage after acidification on calcium (Ca), magnesium (Mg) and phosphate (P) concentrations and on fractional excretion (FE) of these electrolytes. Thirty-two fresh equine urine samples were analysed between December 2016 and July 2020. Complete urinalysis (stick and sediment) was performed on all samples. Ca, Mg, P and creatinine concentrations were measured in supernatant of centrifug...
Germonpru00e9 J, Vandekerckhove LMJ, Raes E, Chiers K, Jans L, Vanderperren K.In this proof-of-concept study, the post-mortem feasibility of dual-energy computed tomography (DECT) in the detection of bone edema-like lesions in the equine foot is described in agreement with the gold standard imaging technique, which is magnetic resonance imaging (MRI). Unassigned: A total of five equine cadaver feet were studied, of which two were pathological and three were within normal limits and served as references. A low-field MRI of each foot was performed, followed by a DECT acquisition. Multiplanar reformations of DECT virtual non-calcium images were compared with MRI for the de...
Gonzalez-Castro RA, Carnevale EM.Phospholipase C Zeta 1 (PLCZ1) is considered a major sperm-borne oocyte activation factor. After gamete fusion, PLCZ1 triggers calcium oscillations in the oocyte, resulting in oocyte activation. In assisted fertilization, oocyte activation failure is a major cause of low fertility. Most cases of oocyte activation failures in humans related to male infertility are associated with gene mutations and/or altered PLCZ1. Consequently, PLCZ1 evaluation could be an effective diagnostic marker and predictor of sperm fertilizing potential for in vivo and in vitro embryo production. The characterization ...
Macedo IS, Lara FA, Barbosa HS, Saraiva EM, Menna-Barreto RFS, Mariante RM., responsible for causing toxoplasmosis, is a prevalent food and waterborne pathogen worldwide. It commonly infects warm-blooded animals and affects more than a third of the global human population. Once ingested, the parasite enters the host's small intestine and rapidly disseminates throughout the body via the bloodstream, infiltrating various tissues. Leukocyte-driven responses are vital against , with neutrophils playing a dual role: swiftly recruited to infection sites, releasing inflammatory mediators, and serving as a replication hub and Trojan horses, aiding parasite spread. Neutrophil...
Hertel S, Basche S, Schmidt V, Staszyk C, Hannig C, Sterzenbach T, Hannig M.Dental hard tissues from different species are used in dental research, but little is known about their comparability. The aim of this study was to compare the erosive behaviour of dental hard tissues (enamel, dentin) obtained from human, bovine and equine teeth. In addition, the protective effect of the pellicle on each hard tissue under erosive conditions was determined. In situ pellicle formation was performed for 30 min on enamel and dentin samples from all species in four subjects. Calcium and phosphate release was assessed during 120 s of HCl incubation on both native and pellicle-cove...
Son V, Penagos-Tabares F, Hollmann M, Khiaosa-Ard R, Sulyok M, Krska R, Zebeli Q.Pastures are used for grazing and the production of conserved roughage in horses. Yet, the nutritional profile of the forage varies from spring to late summer, affecting equine nutrient supply and health. In addition, environmental factors may also favor plant contaminants such as mycotoxins. This study aimed to determine the nutritional profile and contaminant load of selected horse pastures from early spring till late summer. The nutrient composition (main macronutrients, macro elements and trace elements), as well as mycotoxins, metabolites, pesticides, and plant-derived compounds of seven ...
Zamith Cunha R, Semprini A, Salamanca G, Gobbo F, Morini M, Pickles KJ, Roberts V, Chiocchetti R.Cannabinoid receptors are expressed in human and animal trigeminal sensory neurons; however, the expression in the equine trigeminal ganglion is unknown. Ten trigeminal ganglia from five horses were collected post-mortem from an abattoir. The expression of cannabinoid receptors type 1 (CB1R) and type 2 (CB2R), and the cannabinoid-related receptors like transient receptor potential vanilloid type 1 (TRPV1), peroxisome proliferator-activated receptor gamma (PPARɣ), and G protein-related receptor 55 (GPR55) in the trigeminal ganglia (TG) of the horse were studied, using immunofluorescence on cry...
Viterbo L, Hughes J, Milner PI, Bardell D.The study aimed to investigate if arterial blood analysis in conscious horses presenting with signs of colic and breathing ambient air had diagnostic or prognostic value. Arterial blood samples from 352 horses presenting with colic at a university equine referral hospital were analysed for pH, partial pressure of carbon dioxide (PaCO), partial pressure of oxygen (PaO), concentrations of sodium (Na), potassium (K), ionised calcium (Ca) and chloride (Cl), actual and standardised plasma bicarbonate concentration (HCO (P) and HCO (P, st)), blood and extracellular fluid base excess (Base (B) and Ba...
Risselada M, Worth DB.Tumors of various sizes and locations can create a treatment dilemma in achieving adequate surgical margins when sufficient free tissue is not available for closure. Extravascular local adjunctive chemotherapy has been investigated clinically to aid in achieving local tumor control in animals with naturally occurring neoplastic disease. Local chemotherapy can be an alternative primary or a local adjunctive treatment. This is a summary of relevant findings of and studies on local chemotherapeutic delivery through carrier media, together with a summary of outcomes of clinical use of local deli...
du Toit N, Pearce CJ.This retrospective clinical study was performed to determine the suitability and success rate of endodontic treatment of equine incisors presenting with apical and periapical disease. Methods: All horses presented to a referral equine dental clinic between March 2013 and December 2019 specifically selected as candidates suitable for endodontic treatment were included in this study. Methods: Initial clinical and radiographic presentation of incisor disorder cases suitable for endodontic treatment were recorded (88 incisors) and follow-up examination for long-term viability (8 months to 5 years)...
Talluri TR, Kumaresan A, Paul N, Elango K, Raval K, Nag P, Legha RA, Pal Y.Despite the vital role of seminal plasma (SP) in maintaining sperm function and aiding gamete interaction in many species, SP is usually removed before cryopreservation of stallion sperm to improve cryosurvival of sperm. The present study assessed if the vital sperm functional parameters of genetically superior stallions producing poor quality semen can be enhanced by the supplementation of heterologous SP from the stallion producing high quality semen. Spermatozoa from poor quality semen producing stallions were divided into three aliquots: two aliquots were supplemented with SP obtained from...
Etemadi F, Tabatabaei Naeini A, Aminlari M.Minerals play vital roles in physiologic processes. Calcium, phosphorus and magnesium are common minerals. Secretion, absorption and homeostasis of these minerals are affected by associations between the active vitamin D and parathyroid hormone (PTH). Objective: The aim of this study was to assess concentrations of vitamin D, PTH and minerals, such as calcium, phosphorus and magnesium in horse sera, as well as associations of these values with lameness in horses. In the references, the reasons for lameness can be deficiency and imbalance of minerals, and clinical observations also confirm this...
Cittadini A, Domu00ednguez R, Sarriu00e9s MV, Pateiro M, Lorenzo JM.This study aimed to evaluate the effect of the total or partial replacement of NaCl by a commercial low-salt mixture Pansalt® (T1) or Kombu (L. ochroleuca) seaweed powder (T2), respectively, on the quality properties of dry-cured foal "cecina". Salt reformulation unaffected fat percentages, decreased (P < 0.001) moisture and ash contents, while protein amounts increased (P < 0.001) in the T2 batch. Considering the physicochemical variables, any significant differences were observed among batches, except for a*, water activity, and springiness values. T1 and T2 samples presented a si...
Nogueira WA, Ferreira Padilha FG, Angelo Luiz M, da Silva Salomu00e3o N, Monteiro Fonseca AB, Reis Ferreira AM.This study aimed to analyze effect of physical exercise in hemogasometric and electrolytic profiles of young Mangalarga Marchador horses beginning training for gait competitions. Six Mangalarga Marchador gaited horses with 6 months of training were evaluated. The ages ranged from three and a half to five years and included four stallions and two mares, with mean (±S.D.) body weight of 435±30Kg. Venous blood samples were collected from the horses, rectal temperature and HR were measured before and immediately after the gait test, and blood samples were used for hemogasometric and laboratory a...
Fielding CL, Deane EL, Major DS, Mayer JR, Love JC, Peralez MS, Magdesian KG.The addition of calcium to resuscitation fluids is a common practice in horses, but studies evaluating the effects of calcium supplementation are limited. In healthy horses, decreases in heart rate and changes in serum electrolyte concentrations have been reported. Objective: Calcium gluconate administration at a rate of 0.4 mg/kg/min to eliminated endurance horses with metabolic problems will affect heart rate, gastrointestinal sounds, and serum electrolyte concentrations. Methods: Endurance horses eliminated from the Tevis Cup 100-mile (160 km) endurance ride for metabolic problems and req...
Alipour A, Akrami Mohajeri F, Javdan G, Pourramezani F, Fallahzadeh H, Khalili Sadrabad E.In recent years, the mare's milk has been introduced as a rich source of nutrients with hypoallergic characteristics which is widely used for Iranian infants. The present study aimed to investigate the heavy metal concentration of mare's milk and its consumption risk assessment. About 88 mare's milk was collected from Yazd, the centre of Iran, during the summer of 2020. The raw mare's milk was digested and analysed for mineral and heavy metal content (As, Ca, Cd, Co, Cu, Fe, Mg, Mn, Ni, P, Pb and Zn) by ICP-OES. To estimate the health hazard for consumers the Estimated Daily Intake (EDI), Haza...
Garhwal R, Bhardwaj A, Sangwan K, Mehra R, Pal Y, Nayan V, Iquebal MA, Jaiswal S, Kumar H.This current research set out to characterize Halari donkey milk by investigating its nutritional constituents, including its proximate analysis, water activity, titratable acidity, energy, and microbiological analysis. A comprehensive profiling of vitamins, minerals, and amino acids was also carried out. It was found that the composition of Halari donkey milk was consistent with previously published donkey milk literature and was comparable to that of human milk. Halari donkey milk has low 0.86 ± 0.04% fat content, 2.03 ± 0.03% protein content, 0.51 ± 0.05% ash content, and high 5.75 ± 0....
Marichal G, Trigo P, Soto C, Meikle A, Suu00e1rez G.The Raid Uruguayo (RAID) is an equestrian endurance competition. This study characterized the hydroelectrolytic parameters (Na, K, Cl, tCa, and iCa), hematocrit (Ht), total plasma protein (TPP), and blood pH from 900 equine athletes (finishers and non-finishers) competing over distances of 80 to 115 km under different climate conditions. Paired blood samples were taken prior to the start of the competition (sample 1) and at the end of the race or at the time of leaving the competition (sample 2). The association of the comfort index (CI: low, moderate, and high) with blood parameters was evalu...
Sanmartu00ed J, Robles-Guirado JA, Jose-Cunilleras E, Bassols A.The determination of iCa and iMg is important in veterinary medicine, but their immediate determination in whole blood is not always possible. Their stability in other sample types and the existence of interferences must be evaluated before its use. Objective: We aimed to analyze the effects of storage time on the stability of iCa, iMg, and other analytes in whole blood, plasma, and serum samples in horses and assess the interference of heparin in these measurements. Methods: Whole blood, heparin-plasma, and serum samples from 10 horses were stored at 4°C and analyzed 1, 2, 3, 4, 5, 6, 7, 8, ...
The donkey milk has a remarkable similarity to human milk, in addition to its valuable nutritional composition and content of numerous immune factors. The donkey milk is the subject of research worldwide, and data from the literature suggest significant differences with respect to the contents of individual components. However, some basic characteristics of donkey milk have been established: low contents of fat and cholesterol, total proteins and casein and high contents of lactose, whey proteins, calcium, selenium, and Vitamin D3. The donkey milk is rich in various protective proteins (α-lac...
Waller AP, Lindinger MI.Oral electrolyte supplementation may influence acid-base state during exercise due to the intestinal absorption of administered water and electrolytes used to mitigating sweat losses. This study examined the effect of pre-exercise electrolyte supplementation (3 and 8 L) on plasma acid-base variables at rest, during moderate intensity exercise and during recovery. It was hypothesized that electrolyte supplementation will result in improved acid-base state compared to the alkalosis typical of prolonged exercise. In randomized crossover fashion, four horses were administered 3 L or 8 L of a hypot...
Umair M, Claes A, Buijtendorp M, Cuervo-Arango J, Stout TAE, Henning H.Artificial insemination with chilled stallion semen is hampered by a limited period of maximum fertility maintenance (24-48 h). This study used multiparametric flow cytometry to simultaneously measure reactive oxygen species (ROS) production, mitochondrial function or [Ca ] and plasma membrane fluidity in viable, acrosome-intact spermatozoa, with the aim of providing insight into changes in sperm function during storage at 5°C. High proportions of viable and acrosome-intact spermatozoa (71 ± 8%) remained after 96 h of storage demonstrating that the basic integrity of the cells was we...
Massu00e1nyi M, Halo M, Massu00e1nyi P, Mlynekovu00e1 E, Greu0144 A, Formicki G, Halo M.Health state of animals undergoing experimental procedures is an important topic nowadays, as even the small changes can influence the outcome of entire outcomes. Main aim of the study was to evaluate the influence of horse training on variety of blood parameters including mineral profile, energy profile, hepatic profile and haematology. In the experiment, the studied group of horses underwent training programme which consisted of transportation, lounging, riding, jumping, racing, treadmill training and shoeing. Blood samples were collected and later evaluated at the beginning, in the middle a...
Bazzano M, Arfuso F, Bonfili L, Eleuteri AM, McLean A, Serri E, Spaterna A, Laus F.According to FAO reports, the global mule population counts about 9 million mules. This hybrid cross of a male donkey and a female horse is mainly used for draft purposes because they are thought to be strong and hardy animals. Most consider mules to be less susceptible to disease and fatigue compared to horses. Therefore, the aim of this study was to investigate the effects of fieldwork on biochemical variables and serum amyloid A in working mules. Blood samples were collected from 10 healthy, female, working mules before and after 8 h of fieldwork. According to statistical analysis, a signif...
Melo UP, Palhares MS, Ferreira C, Leme FOP, Gheller VA.This study aimed to evaluate the effects of the total parenteral nutrition associated with glutamine, enteral fluid therapy with or without glutamine, and fluid therapy on the acid-base and electrolyte balance of horses starved after exploratory laparotomy. Sixteen healthy male and female adult horses of mixed breed, aged between 4 and 14 years, and having a mean body weight of 248.40 ± 2.28 kg and a body score index of 3-4 (scale of 1-5) were divided into four groups with four animals per group. After an adaptation period of 30 days, they were randomly divided into four experimental groups: ...
Richards MA, Clarke JD, Saravanan P, Voigt N, Dobrev D, Eisner DA, Trafford AW, Dibb KM.Transverse (t) tubules are surface membrane invaginations that are present in all mammalian cardiac ventricular cells. The apposition of L-type Ca(2+) channels on t tubules with the sarcoplasmic reticulum (SR) constitutes a "calcium release unit" and allows close coupling of excitation to the rise in systolic Ca(2+). T tubules are virtually absent in the atria of small mammals, and therefore Ca(2+) release from the SR occurs initially at the periphery of the cell and then propagates into the interior. Recent work has, however, shown the occurrence of t tubules in atrial myocytes from sheep. As...
White IG.When sperm of the ram, bull, boar and stallion are cold-shocked by rapid cooling to near freezing point, motility and metabolic activity are irreversibly depressed and the acrosome and plasma membrane disrupted. Ram sperm become susceptible to cold shock in the proximal corpus region of the epididymis when the cytoplasmic droplet has moved backwards to the distal portion of the sperm midpiece. The membrane constituents phospholipids and cholesterol are important in cold shock which causes loss of lipid from sperm. The susceptibility of sperm to cold shock is linked with a high ratio of unsatur...
Huser CA, Davies ME.Chondrocyte apoptosis is an important factor in the progression of osteoarthritis. This study aimed to elucidate the mechanisms involved upstream of caspase 9 activation and, in particular, calcium signaling and mitochondrial depolarization. Methods: Articular cartilage explants obtained from healthy horses were subjected to a single impact load (500-gm weight dropped from a height of 50 mm) and cultured in vitro for up to 48 hours. Chondrocyte death was quantified by the TUNEL method. Release of proteoglycans was determined by the dimethylmethylene blue assay. Weight change was measured, and ...
Scepek S, Coorssen JR, Lindau M.Using the patch-clamp technique, we studied the role of protein phosphorylation and dephosphorylation on the exocytotic fusion of secretory granules with the plasma membrane in horse eosinophils. Phorbol 12-myristate 13-acetate (PMA) had no effect on the amplitude and dynamics of degranulation, indicating that the formation of fusion pores is insensitive to activation of protein kinase C (PKC). Fusion pore expansion, however, was accelerated approximately 2-fold by PMA, and this effect was abolished by staurosporine. Elevating intracellular Ca2+ to 1.5 microM also resulted in a 2-fold accelera...
Textor JA, Tablin F.To investigate and compare clinically relevant Platelet-rich plasma (PRP) activation methods. Methods: Experimental. Methods: PRP was prepared from 6 equine subjects. Activation of the PRP was performed by 4 methods (autologous thrombin, bovine thrombin, calcium chloride (CaCl(2) ), or freeze-thaw). The resultant PDGF-BB (where PDGF is platelet-derived growth factor) and TGFβ1 (where TGFβ is transforming growth factor beta) levels in PRP releasates were quantified by Enzyme-linked immunosorbent assay (ELISA) and compared. Growth factor contents were also compared between platelet-rich clots ...
Medhammar E, Wijesinha-Bettoni R, Stadlmayr B, Nilsson E, Charrondiere UR, Burlingame B.A comprehensive review is presented of the nutrient composition for buffalo, mare, and dromedary camel milks at the level of breed, and species-level data for yak, mithun, musk ox, donkey, Bactrian camel, llama, alpaca, reindeer and moose milks. Average values of nutrients were calculated and compared. Interspecies values (g 100 g⁻¹) were 0.7-16.1 for total fat, 1.6-10.5 for protein, 2.6-6.6 for lactose, and 67.9-90.8 for water. Reindeer and moose milks had the highest fat and protein concentrations and the lowest lactose contents. Mare and donkey milks had the lowest protein and fat conten...
Cheng FP, Fazeli A, Voorhout WF, Marks A, Bevers MM, Colenbrander B.Peanut agglutinin (PNA) was used to assess the sperm acrosomal status and the acrosome reaction during gamete interaction in the equine species. PNA exclusively binds to the outer acrosomal membrane of stallion spermatozoa, as was established by transmission electron microscopy. Fluorescein isothiocyanate-PNA (FITC-PNA) labeling was used to monitor sperm acrosomal changes during a prolonged incubation period of 24 hours and during a 2-hours incubation in the presence of 5 microM calcium ionophore A23187. In addition, after a 4-hours preincubation in SP-TALP medium, sperm samples were incubated...
Verheij HM, Volwerk JJ, Jansen EH, Puyk WC, Dijkstra BW, Drenth J, de Haas GH.It is known that His-48 is part of the active center in pancreatic phospholipase. To further elucidate the role of histidine-48 in the active center of pancreatic phospholipase A2, we have modified the enzyme with a number of bromo ketones and methyl benzenesulfonates. Rapid methylation occurred with methyl p-nitrobenzenesulfonate. Methylated phospholipase shows total loss of enzymatic activity whereas binding of substrate and the cofactor Ca2+ remains intact. Amino acid analysis of methylated equine phospholipase showed the loss of the single molecule of histidine and the formation of one mol...
Wang ZW, Nara M, Wang YX, Kotlikoff MI.The effects of sulfhydryl reduction/oxidation on the gating of large-conductance, Ca(2+)-activated K+ (maxi-K) channels were examined in excised patches from tracheal myocytes. Channel activity was modified by sulfhydryl redox agents applied to the cytosolic surface, but not the extracellular surface, of membrane patches. Sulfhydryl reducing agents dithiothreitol, beta-mercaptoethanol, and GSH augmented, whereas sulfhydryl oxidizing agents diamide, thimerosal, and 2,2'-dithiodipyridine inhibited, channel activity in a concentration-dependent manner. Channel stimulation by reduction and inhibit...
Loux SC, Crawford KR, Ing NH, Gonzu00e1lez-Fernu00e1ndez L, Macu00edas-Garcu00eda B, Love CC, Varner DD, Velez IC, Choi YH, Hinrichs K.In vitro fertilization does not occur readily in the horse. This may be related to failure of equine sperm to initiate hyperactivated motility, as treating with procaine to induce hyperactivation increases fertilization rates. In mice, hyperactivated motility requires a sperm-specific pH-gated calcium channel (CatSper); therefore, we investigated this channel in equine sperm. Motility was assessed by computer-assisted sperm motility analysis and changes in intracellular pH and calcium were assessed using fluorescent probes. Increasing intracellular pH induced a rise in intracellular calcium, w...
Hartmann J, Lindau M.Exocytosis begins with formation of a small fusion pore which then expands allowing rapid release of granular contents. We studied the influence of cytoplasmic free Ca2+ ([Ca2+]i) on the conductance of the initial pore and on the dynamics of subsequent expansion in horse eosinophils using the patch clamp technique. The mean initial conductance is approximately 200 pS independent of [Ca2+]i. This value is close to that previously found in beige mouse mast cells. The pore subsequently expands by 18 nS/s at [Ca2+]i < 10 nM, by 40 nS/s at [Ca2+]i = 1.5 microM and by 90 nS/s at [Ca2+]i = 10 micr...
Pesch S, Bergmann M, Bostedt H.Seminal plasma is very important for sperm metabolism as well as sperm function and survival and transport in the female genital tract. Analysis of enzyme activities and concentrations of elements can estimate integrity and function of sperm cell membranes. In man much data are available about biochemical analyses of seminal plasma. However, not many studies have been conducted in horses yet. We collected ejaculates from 72 stallions, measured the volume, obtained seminal plasma by centrifugation and examined spermatozoa with light microscopy for motility, concentration, for dead sperm and mor...
Byrd SK, McCutcheon LJ, Hodgson DR, Gollnick PD.This study examined the effects of acute high-intensity exercise on the rate and capacity of Ca2+ uptake and Ca2+-stimulated adenosinetriphosphatase (ATPase) activity of the sarcoplasmic reticulum and the reversibility of these effects. Thoroughbred horses were run at maximal O2 uptake on a high-speed treadmill until fatigued. Muscle temperatures and biopsy samples were collected at rest, immediately after exercise, and 30 and 60 min after exercise. Blood samples were collected at rest and 5 min after exercise. Muscle and blood (lactate concentration) were three- and fivefold greater than pre-...
Toribio RE, Kohn CW, Capen CC, Rosol TJ.Parathyroid hormone (PTH) is secreted by the chief cells of the parathyroid gland in response to changes in ionized calcium (Ca(2+)) concentrations. In this study, we measured PTH secretion, and PTH mRNA and calcium-sensing receptor (CaR) mRNA expression by equine parathyroid chief cells in vitro. We also evaluated the effects of interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha on PTH secretion, and PTH and CaR mRNA expression. The relationship between PTH and Ca(2+) was inversely related. PTH secretion decreased from 100% (day 0) to 13% (day 30). PTH mRNA expression decline...
Malisauskas M, Zamotin V, Jass J, Noppe W, Dobson CM, Morozova-Roche LA.The calcium-binding equine lysozyme has been found to undergo conversion into amyloid fibrils during incubation in solution at acidic pH. At pH 4.5 and 57 degrees C, where equine lysozyme forms a partially unfolded molten globule state, the protein forms protofilaments with a width of ca. 2 nm. In the absence of Ca(2+) the protofilaments are present as annular structures with a diameter of 40-50 nm. In the presence of 10 mM CaCl(2) the protofilaments of equine lysozyme are straight or curved; they can assemble into thicker threads, but they do not appear to undergo circularisation. At pH 2.0, ...
Billah MM, Lapetina EG.Stimulation of horse platelets with platelet-activating factor (PAF) induces a rapid degradation of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2]. Addition of 0.1 microM PAF for 5 sec to platelets prelabeled with 32P induces a 50% loss of [32P]PtdIns(4,5)P2. 32P-Labeled phosphatidylinositol 4-monophosphate (PtdIns4P) and [32P]phosphatidylinositol (PtdIns) also are decreased, albeit at a slower rate. Loss of 32P radioactivity correlates with a net loss of fatty acids from both polyphosphoinositides. Stimulation of platelets with PAF also produces formation of [32P]phosphatidic acid and ...
Gustafson MB, Martin RB, Gibson V, Storms DH, Stover SM, Gibeling J, Griffin L.This work determined whether mineral dissolution due to prolonged testing or storage of bone specimens in normal saline would alter their elastic modulus. In one experiment, small pieces of equine third metacarpal bone were soaked in normal saline supplemented with varying amounts of CaCl2. Changing Ca ion concentrations in the bath were monitored and the equilibrium concentration was determined. In a second experiment, the elastic moduli of twenty 4 x 10 x 100 mm equine third metacarpal beams were determined non-destructively in four-point bending. Half the beams were then soaked for 10 days ...
Cu00f4tu00e9 GP, Smillie LB.Whereas skeletal muscle tropomyosin binds strongly to muscle F-actin in a buffer containing 30 mM KCl and 1-2 mM free Mg2+, equine platelet tropomyosin only binds stoichiometrically (1 tropomyosin molecule per 6 actin monomers) at higher Mg2+ concentrations (7-8 mM free Mg2+). At low free Mg2+ concentrations (1.5 mM) the binding of the platelet protein is only marginally increased by raising the KCl concentration to an optimal value (0.10-0.20 M). This weaker binding can be attributed to the relatively poor head-to-tail polymerization of platelet tropomyosin and its fewer actin-binding sites. ...
Gonzu00e1lez-Fernu00e1ndez L, Macu00edas-Garcu00eda B, Loux SC, Varner DD, Hinrichs K.Protein tyrosine phosphorylation (PY) is a hallmark of sperm capacitation. In stallion sperm, calcium inhibits PY at pH 7.8). These results show for the first time a role for calcium/calmodulin-dependent kinases in PRKA-dependent sperm PY; a non-PRKA-dependent pathway regulating sperm PY; and the apparent involvement of the FAK family of protein tyrosine kinases downstream in both pathways.
Mayhew IG, Whitlock RH, Tasker JB.Cerebrospinal fluid (CSF) samples were collected from the atlanto-occipital (AO) and lumbosacral (LS) subarachnoid spaces of 24 horses and 21 ponies that had no clinical evidence of neurologic disease. Depth of needle insertion, pressures, refractive index, rapid reagent strip test (protein, glucose, blood, pH) results, cell counts, content of protein, glucose, sodium, potassium, chloride, calcium, phosphorus, urea nitrogen, and cholesterol, and activities of creatine phosphokinase, aspartate transaminase, lactic dehydrogenase, and alkaline phosphatase were determined. The resulting clinical r...
Burnaugh L, Sabeur K, Ball BA.Low-level production of the superoxide anion (O2*-) is an important signal transduction event in sperm function including capacitation; however, excessive production of O2*- can be detrimental to sperm function. The objective of this study was to assess dihydroethidium (DHE) as a probe for O2*- in equine spermatozoa. Ejaculated spermatozoa were separated by centrifugation over a Percoll gradient (40:80), and loaded with DHE (2.0 microM) as well as with calcein-acetoxymethylester (CAM, 7.8 nM) to determine cell viability. In Experiment 1, cells were incubated with the xanthine-xanthine oxidase ...
Dobrinski I, Smith TT, Suarez SS, Ball BA.Interaction of equine spermatozoa with oviductal epithelial cells (OEC) prolongs sperm viability and maintains low intracellular calcium concentration ([Ca2+]i) in spermatozoa. Experiments were designed to investigate 1) whether release of spermatozoa from OEC in vitro is associated with elevated [Ca2+]i and 2) whether soluble products from OEC or direct membrane contact between spermatozoa and OEC mediates the effects of OEC on sperm [Ca2+]i. In the first experiment, changes in [Ca2+]i in spermatozoa loaded with indo-1 acetoxymethylester were determined in motile spermatozoa released from OEC...
Siess W, Lapetina EG.Phospholipase C has been studied in homogenates, total particulate and soluble fractions of horse and human platelets. This enzyme, assayed with exogenous L-3-phosphatidyl[14C]inositol, is predominantly localized in the soluble fraction and its distribution parallels that of lactate dehydrogenase. A small percentage of activity present in the particulate fraction seems to be due to contamination with soluble enzyme. Enzyme from horse and human platelets appears identical, having a Km of 0.10-0.15 mM, acid pH optimum (pH 5.5) and showing Ca2+-dependency and weak inhibition by deoxycholate. Anal...
The Journal of physiologyFebruary 16, 2000
Volume 523 Pt 1, Issue Pt 1 131-138 doi: 10.1111/j.1469-7793.2000.t01-3-00131.x
Wang YX, Kotlikoff MI.1. The signalling pathway underlying histamine activation of non-selective cation channels was investigated in single equine tracheal myocytes. Application of histamine (100 microM) activated the transient calcium-activated chloride current (ICl(Ca)) and sustained, low amplitude non-selective cation current (ICat). The H1 receptor antagonist pyrilamine (10 microM) blocked activation of ICl(Ca) and ICat. Simultaneous application of histamine (100 microM) and caffeine (8 mM) during H1 receptor blockade activated ICl(Ca), but not ICat. Neither the H2 receptor antagonist cimetidine (20 microM) nor...
The Journal of physiologyApril 15, 1996
Volume 492 ( Pt 2), Issue Pt 2 347-358 doi: 10.1113/jphysiol.1996.sp021313
Fleischmann BK, Wang YX, Pring M, Kotlikoff MI.1. The relationship between voltage-dependent calcium channel current (I(Ca)) and cytosolic free calcium concentration ([Ca2+]i) was studied in fura-2 AM-loaded equine tracheal myocytes at 35 degrees C and 1.8 mM Ca2+ using the nystatin patch clamp method. The average cytosolic calcium buffering constant was 77 +/- 3 (n = 14), and the endogenous calcium buffering constant component is likely to be between 15 and 50. 2. I(Ca) did not evoke significant calcium-induced calcium release (CICR) since (i)[Ca2+]i scaled with the integrated I(Ca) over the full voltage range of evoked calcium currents, ...
Arienti G, Carlini E, De Cosmo AM, Di Profio P, Palmerini CA.Human semen contains membranous vesicles called prostasomes. They are secreted by the prostate gland and contain large amounts of cholesterol, sphingomyelin, and Ca2+. Prostasomes enhance the motility of ejaculated spermatozoa and are involved in a number of additional biological functions. No prostasome-like vesicles have been described in horse semen up to now. We have demonstrated the presence of prostasome-like vesicles in the equine semen and characterized them as to size, morphology, and lipid composition; we have found that they are similar to human prostasomes in many respects. We prop...
van der Harst MR, Brama PA, van de Lest CH, Kiers GH, DeGroot J, van Weeren PR.In articular joints, the forces generated by locomotion are absorbed by the whole of cartilage, subchondral bone and underlying trabecular bone. The objective of this study is to test the hypothesis that regional differences in joint loading are related to clear and interrelated differences in the composition of the extracellular matrix (ECM) of all three weight-bearing constituents. Methods: Cartilage, subchondral- and trabecular bone samples from two differently loaded sites (site 1, dorsal joint margin; site 2, central area) of the proximal articular surface of 30 macroscopically normal equ...
Wilson G, Drust B, Morton JP, Close GL.Professional jockeys are unique amongst weight-making athletes given that they face the requirement to make weight daily. Furthermore, unlike other weight-limited sports, jockeys who have engaged in rapid weight loss cannot fully rehydrate prior to competition because post-race weight must not be more than 1 kg different to their pre-race weight. As such, jockeys have reported a variety of acute and chronic methods to make weight that include sporadic eating, caloric restriction, diuretics, laxatives, vomiting and fluid restriction as well as regular use of sweat suits and saunas. Typical dai...
Ochi S, Oda M, Nagahama M, Sakurai J.Clostridium perfringens alpha-toxin is able to lyse various erythrocytes. Exposure of horse erythrocytes to alpha-toxin simultaneously induced hot-cold hemolysis and stimulated production of diacylglycerol and phosphorylcholine. When A23187-treated erythrocytes were treated with the toxin, these events were dependent on the concentration of extracellular Ca2+ . Incubation with the toxin of BAPTA-AM-treated horse erythrocytes caused no hemolysis or production of phosphorylcholine, but that of the BAPTA-treated erythrocytes did. When Quin 2-AM-treated erythrocytes were incubated with the toxin i...
Wang YX, Kotlikoff MI.We investigated the muscarinic activation of Ca(2+)-activated Cl- currents [ICl(Ca)] in voltage-clamped equine tracheal myocytes. The threshold of cytosolic free Ca2+ concentration ([Ca2+]i) required for activation of ICl(Ca) was 202 +/- 22 nM, and full activation of the current occurred at 771 +/- 31 nM. Hexahydro-sila-difenidol (M3 antagonist) inhibited the methacholine-induced phasic [Ca2+]i increase and ICl(Ca) in a concentration-dependent manner, whereas methoctramine (M2 antagonist) only slightly attenuated the [Ca2+]i increase and ICl(Ca) (14.8 and 21.4%, respectively), consistent with ...
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