Topic:Biochemistry
The study of biochemistry in horses encompasses the chemical processes and substances that occur within equine organisms. This field investigates the molecular interactions and pathways that are fundamental to horse physiology, including metabolism, enzyme activity, and genetic expression. Key areas of interest include the examination of metabolic disorders, nutrient absorption, and the biochemical basis of muscle function and energy production. Researchers utilize biochemical analysis to understand health and disease mechanisms in horses, contributing to the development of diagnostic tools and therapeutic strategies. This page gathers peer-reviewed studies and scholarly articles that explore various biochemical processes and their implications for equine health and performance.
Detection of the growth hormone secretagogue MK-0677 in equine hair following oral administration. MK-0677 (ibutamoren) is an orally active non-peptide growth hormone secretagogue that binds to the ghrelin receptor stimulating the secretion of endogenous growth hormone. It is one of the most prevalent performance-enhancing compounds currently available online and is potentially subject to abuse both in human and equine sports. The aim of the current study was to investigate whether it could be detected in equine hair following oral administration of MK-0677 mesylate to a Thoroughbred racehorse. MK-0677 and its O-dealkylated metabolite were extracted using an existing method for prohibited s...
Plasma Amino Acid Concentration in Obese Horses with/without Insulin Dysregulation and Laminitis. Laminitic horses commonly suffer from an endocrine disease such as equine metabolic syndrome. Hyperinsulinemia is considered a key factor in the pathogenesis of laminitis. Since insulin also affects protein turnover in the body, the resting plasma amino acid concentrations of obese horses that were presented for a combined glucose insulin test (CGIT) were determined. In total, 25 obese horses and two lean horses with recurrent laminitis underwent a CGIT. Of these, five were not insulin dysregulated (obese), 14 were insulin dysregulated (ID), and eight were insulin-dysregulated and laminitic (I...
Analysis of Proteins and Peptides of Highly Purified CD9+ and CD63+ Horse Milk Exosomes Isolated by Affinity Chromatography. Exosomes are nanovesicles with a 40-150 nm diameter and are essential for communication between cells. Literature data suggest that exosomes obtained from different sources (cell cultures, blood plasma, urea, saliva, tears, spinal fluid, milk) using a series of centrifugations and ultracentrifugations contain hundreds and thousands of different protein and nucleic acid molecules. However, most of these proteins are not an intrinsic part of exosomes; instead, they co-isolate with exosomes. Using consecutive ultracentrifugation, gel filtration, and affinity chromatography on anti-CD9- and anti-C...
Ocular penetration of oral acetaminophen in horses. Acetaminophen (paracetamol) is increasingly used to treat painful conditions in horses but its ocular penetration has not been studied. Objective: To determine whether orally administered acetaminophen penetrates the aqueous humour of the normal equine eye and report an aqueous humour:serum acetaminophen concentration ratio in horses. Methods: In vivo experiment. Methods: Six privately owned horses with normal ophthalmic examinations weighing 568 ± 65 kg (mean ± standard deviation) and aged 11 ± 4 years were given 20 mg/kg acetaminophen orally every 12 h for a total of s...
Changes in haematological and biochemical parameters in blood serum of horses during exposition to workload stress. 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...
Cocktail drug usage and etofenamate detection in post-race equine urine sample: A case report. A recent trend in the use of high-resolution accurate mass screening (HRAMS) for doping control testing in both human and animal sports has emerged owing to significant improvement in high-resolution mass spectrometry in terms of sensitivity, mass accuracy, mass resolution and mass stability. Several HRAMS methods have been reported for the detection of multidrug residues in human or equine urine. These improved analytical technologies have led to changes in the use of prohibited substances, and the administration of more than one substance at low concentrations as a "cocktail" has become one ...
Enantioselective CE-MS analysis of ketamine metabolites in urine. The chiral drug ketamine has long-lasting antidepressant effects with a fast onset and is also suitable to treat patients with therapy-resistant depression. The metabolite hydroxynorketamine (HNK) plays an important role in the antidepressant mechanism of action. Hydroxylation at the cyclohexanone ring occurs at positions 4, 5, and 6 and produces a total of 12 stereoisomers. Among those, the four 6HNK stereoisomers have the strongest antidepressant effects. Capillary electrophoresis with highly sulfated γ-cyclodextrin (CD) as a chiral selector in combination with mass spectrometry (MS) was us...
Phosphoproteomics for the identification of new mechanisms of cryodamage: the role of SPATA18 in the control of stallion sperm function†. Although recent research has addressed the impact of cryopreservation on the stallion sperm proteome, studies addressing the stallion sperm phosphoproteome are lacking. In the present study, the data set of proteomes of fresh and cryopreserved spermatozoa were reanalyzed, showing that cryopreservation caused significant changes in the phosphoproteome. The phosphoproteins reduced most significantly by cryopreservation were Ca2+binding tyrosine phosphorylation regulated, protein kinase cAMP-activated catalytic subunit beta (CABYR), mitochondria eating protein (SPATA18), A kinase anchoring protei...
ProAKAP4 Concentration Is Related to Sperm Motility and Motile Sperm Subpopulations in Frozen-Thawed Horse Semen. ProAKAP4 is the precursor of AKAP4 (A-kinase Anchor protein 4), the main structural protein of the fibrous sheath of sperm. The amount of proAKAP4 reflects the ability of spermatozoa to maintain the flagellum activity and functionality up to the site of fertilization and is positively correlated with progressive motility in several mammalian species. The aim of this study was to investigate the relationship between proAKAP4 concentration with horse sperm motility descriptors and spermatic motile subpopulations. For this purpose, a total of 48 ejaculates from 13 different stallions were analyze...
Transient increases in glutamate dehydrogenase (GLDH) activity occur in neonatal foals. Liver analyte measurement is important in the evaluation of sick animals. Liver injury in horses is recognized by increased glutamate dehydrogenase (GLDH), sorbitol dehydrogenase (SDH), and aspartate aminotransferase (AST) activities, whereas biliary pathology is identified by increased alkaline phosphatase and γ-glutamyl transferase (GGT) activities or bilirubin concentrations. We have observed high GLDH, but not SDH, activities in neonatal foals admitted for conditions other than liver disease. Only one previous study have evaluated GLDH activity over time in healthy neonatal foals; however...
Expression of matrix metalloproteinases (MMPs)-2/-7/-9/-14 and tissue inhibitors of MMPs (TIMPs)-1/-2 in bovine cutaneous fibropapillomas associated with BPV-2 infection. Bovine papillomaviruses -1/-2 (BPVs) are small non-enveloped double-stranded DNA viruses able to infect the skin of bovids and equids, causing development of neoplastic lesions such as bovine cutaneous fibropapillomas and equine sarcoid. Matrix metalloproteinases (MMPs) are a group of zinc-dependent endopeptidases that degrade basal membrane and extracellular matrix, whose function is essential in physiological processes such as tissue remodeling and wound healing. MMPs activity is finely regulated by a balancing with expression of tissue inhibitors of MMPs (TIMPs), a process that is impaired ...
Plasma Amino Acids in Horses Suffering from Pituitary Pars Intermedia Dysfunction. Pituitary pars intermedia dysfunction is one of the most common diseases of aged horses and ponies. In Parkinson's disease, which is, similar to PPID, a disease that involves oxidative damage to dopaminergic pathways but with different clinical signs, alterations to the serum amino acid profile have been reported. To examine changes in the plasma amino acid profile in horses with PPID, EDTA plasma of horses that were presented for various reasons that required laboratory examinations of blood anticoagulated with EDTA was collected. With this plasma, the basal ACTH concentration as well as the ...
Short-Term Exposure to Ciprofloxacin Reduces Proteoglycan Loss in Tendon Explants. Fluoroquinolone antibiotics are associated with increased risk of tendinopathy and tendon rupture, which can occur well after cessation of treatment. We have previously reported that the fluoroquinolone ciprofloxacin (CPX) reduced proteoglycan synthesis in equine tendon explants. This study aimed to determine the effects of CPX on proteoglycan catabolism and whether any observed effects are reversible. Equine superficial digital flexor tendon explant cultures were treated for 4 days with 1, 10, 100 or 300 µg/mL CPX followed by 8 days without CPX. The loss of [S]-labelled proteoglycans and che...
Evaluation of a Comprehensive Profile of Salivary Analytes for the Diagnosis of the Equine Gastric Ulcer Syndrome. In this report, the measurement of salivary biomarkers as an aid for diagnosis of equine gastric ulcer syndrome (EGUS) was studied. A comprehensive panel of 23 salivary analytes was measured in the saliva of horses affected by EGUS and compared to healthy animals and horses with other diseases clinically similar to EGUS but with a negative diagnosis at gastroscopic examination. A total of 147 horses were included in the study and divided into heathy population (n = 12), the EGUS group (n = 110), and the group of horses with other diseases (n = 25). From the 23 analytes studied, 17 showed incre...
Comparative Ungual Drug Uptake Studies: Equine Hoof Membrane vs. Human Nail Plate. Human nail diseases, mostly caused by fungal infections, are common and difficult to treat. The development and testing of new drugs and drug delivery systems for the treatment of nail diseases is often limited by the lack of human nail material for permeation studies. Animal material is frequently used, but there are only few comparative data on the human nail plate, and there is neither a standardized test design nor a nail bed analogue to study drug uptake into the nail. In this study, a new permeation device was developed for permeation studies, and the permeation behavior of three model s...
Cartilage-Sparing Properties of Equine Omega Complete in an Organ Culture Model of Cartilage Inflammation. The purpose of this study was to determine anti-inflammatory and/or chondroprotective effects of Equine Omega Complete (EOC) on cartilage explants stimulated with lipopolysaccharide (LPS). Explants were aseptically prepared from the intercarpal joints of 17 market-weight pigs and placed in culture at 37°C for a total of 120 hours. For the final 96 hours, explants were conditioned with a simulated digestion extract of EOC (0, 36 or 180 μL/mL), and for the final 48 hours explants were stimulated with LPS (0 or 15µg/mL). Media was removed and replaced every 24 hours. Samples from the final 48 ...
Relationship between estrus endometrial edema and progesterone production in pregnant mares two weeks after ovulation. Progesterone plays a crucial role in the maintenance of pregnancy from conception to about 100-120 days of gestation when placenta becomes the main source of gestagens. The aim of the study was to test progesterone concentration 14 days after ovulation in pregnant mares and relate it to peak estral endometrial edema and the presence of intrauterine fluid (IUF) after artificial insemination (AI), the number of treatments against IUF, and the time from AI to the day when the uterus was found free of fluid. Results: Mares were divided into two groups: group A (n = 13; age 10.8 ± 4.5 y...
Effects of different grains on bacterial diversity and enzyme activity associated with digestion of starch in the foal stomach. Compared with the stomach of ruminant cattle, the stomach of horse is small and mainly for chemical digestion, but the microorganisms in the stomach play an important role in maintaining the homeostasis of the internal environment. Due to the complexity of the microbes in the stomach, little is known about the diversity and structure of bacteria in the equine stomach. Grains are the main energy source for plant-eating livestock and energy is derived through enzymatic hydrolysis of grains into glucose or their microbial fermentation into Volatile fatty acids (VFA). However, the mechanism throug...
Investigation of high gamma-glutamyltransferase syndrome in California Thoroughbred racehorses. Increases in serum gamma-glutamyltransferase (GGT) activity have been reported in Thoroughbred (TB) racehorses and associated with maladaptation to training but the underlying etiology remains unknown. Objective: Classify the etiology of high GGT syndrome in racing TBs by assessment of pancreatic enzymes, vitamin E concentrations, and both a candidate gene and whole genome association study. We hypothesized that a genetic variant resulting in antioxidant insufficiency or pancreatic dysfunction would be responsible for high GGT syndrome in TBs. Methods: A total of 138 California racing TBs. Amy...
Identification of mare milk adulteration with cow milk by liquid chromatography-high resolution mass spectrometry based on proteomics and metabolomics approaches. Mare milk(MM)production is lower than that of cow milk (CM), making it a premium product. Unfortunately, sellers adulterate MM with cheap CM to unscrupulously gain more profits. This study aimed to analyze MM adulteration with CM using proteomics and metabolomics. Using univariate and multivariate statistical analysis, the relative abundances of certain proteins of caseins and secretoglobin family 1D member were found to be higher with a higher CM admixture percentage. In addition, several metabolites, such as orotic and 4-aminonicotinic acids, increased in the mare-cow milk mixture with an in...
Effects of the Ingestion of Ripe Mangoes on the Squamous Gastric Region in the Horse. Erosions and gastric ulcers may be present in horses at any age and under different conditions of rearing and handling. In tropical regions, horses can feed on fruits rich in soluble carbohydrates, such as mangoes, but little is known about how these foods interact with their digestive systems. To test the hypothesis that the ingestion of ripe mangoes with peels could cause disturbances in the digestive processes of horses, an experiment was developed to monitor animals that had free access to ripe mangoes in their pasture areas. Horses (purebred Arabians, n = 5; ~340 kg, ~13 years) were evalu...
Kallikrein proteoforms and reproductive parameters in stallion are conditioned by climate. Horses are seasonal polyoestrous animals, and the photoperiod is the main factor modulating their reproductive activity. There is no consensus on the andrological and biochemical factors that influence breeding seasonality. To assess the involvement of climate in reproduction, Mangalarga Marchador stallions were monitored over 1 year regarding semen quality and seminal plasma proteome. Here, we show that kallikrein (KLKs) proteoforms in seminal plasma are involved in climate conditioning of reproduction. During the breeding season, greater abundance and different types of KLKs occurred simult...
Metabolic profiling of preovulatory follicular fluid in jennies. Follicular fluid is formed from the transudation of theca and granulosa cells in the growing follicular antrum. Its main function is to provide an optimal intrafollicular microenvironment to modulate oocyte maturation. The aim of this study was to determine the metabolomic profile of preovulatory follicular fluid (PFF) in jennies. For this purpose, PFF was collected from 10 follicles of five jennies in heat. Then, PFF samples were analysed by nuclear magnetic resonance (NMR) and heteronuclear single quantum correlation (2D H/C HSQC). Our study revealed the presence of at least 27 metabolites i...
Changes in Acute Phase Response Biomarkers in Racing Endurance Horses. This study aimed to evaluate if exercise-induced acute phase response (APR) occurs in endurance horses in response to the race. The study included 23 horses competing in an endurance competition with a successfully passed clinical examination before the race. Blood samples were collected before the start and within 30 min after the end of the race. Haematological and biochemical tests were performed and correlated to acute phase biomarkers changes. Values of calprotectin and haptoglobin (Hp) decreased after the races compared to values before, while concentrations of ceruloplasmin and albumin ...
Safety and efficacy of a feed additive consisting of glyceryl polyethyleneglycol ricinoleate (PEG castor oil) for all animal species (FEFANA asbl). Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of glyceryl polyethyleneglycol ricinoleate (PEG castor oil) as technological feed additive for all animal species. PEG castor oil is safe at a maximum concentration in complete feed of 90 mg/kg for chickens for fattening and other minor growing poultry; 134 mg/kg for laying hens and other laying/breeding birds kept for egg production/reproduction; 121 mg/kg for turkeys for fattening; 162 mg/kg for piglets and other minor growing ; 194 mg/kg for pigs for fattening; 23...
Relation of seminal plasma trace mineral in the Arabian stallion’s semen with the semen characteristics and subsequent fertility. Seminal plasma contains several microelements like Zn, Fe, Se, and Cu that affect sperm motility and male fertility. Biochemical evaluation of seminal plasma trace elements is important for assessing fertility and diagnosing male infertility. Unassigned: The present study was designed to evaluate the effect of seminal fluid trace elements on sperm parameters and fertility in Arabian horses. Unassigned: Ninety-four ejaculates from 25 Arabian stallions (4-27 years old) were used to investigate the effect of seminal fluid trace elements on semen parameters and fertility. Data divided according to...
Measuring Biochemical Variables and Serum Amyloid A (SAA) in Working Mules in Central Italy. 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...
Comparative immune responses after vaccination with the formulated inactivated African horse sickness vaccine serotype 1 between naïve horses and pretreated horses with the live-attenuated African horse sickness vaccine. African horse sickness (AHS) is a non-contagious, high mortality, and insect-borne disease caused by a double-stranded RNA virus from the genus Orbivirus. The study aimed to develop inactivated vaccines serotype 1 inactivated AHS vaccine (IAV) and to compare the effect of IAV on antibody responses in young naïve horses and adult horses pre-immunized with live-attenuated AHS virus (AHSV) serotypes 1, 3, and 4 live-attenuated vaccine (LAV). Unassigned: A total of 27 horses were vaccinated in two trials. Twelve AHS naïve young horses and 15 adult horses were divided into three groups of 4 and 5...
The Influence of Age and Gender on the Serum XOR Activity, Leukocyte Gene Expression of XOR and MPO, and Biochemical Parameters in Newborn Foals. One of the initial responses of the host's innate immunity of newborns against pathogens is the use of oxidative enzymes. This study aimed to evaluate changes in serum xanthine oxidoreductase (XOR) activity, the leukocyte myeloperoxidase (MPO) and XOR genes expression, and some biochemical parameters in healthy Darehshuri newborn foals up to 60 days of life. Blood samples were collected from 16 foals at 1, 7, 15, 30, and 60 days and used for detecting XOR activity, biochemical parameters, and also gene expression by real-time RT-PCR. High activity of XOR was observed at birth, explained by phy...
Generic approach for the discovery of drug metabolites in horses based on data-dependent acquisition by liquid chromatography high-resolution mass spectrometry and its applications to pharmacokinetic study of daprodustat. In drug metabolism studies in horses, non-targeted analysis by means of liquid chromatography coupled with high-resolution mass spectrometry with data-dependent acquisition (DDA) has recently become increasingly popular for rapid identification of potential biomarkers in post-administration biological samples. However, the most commonly encountered problem is the presence of highly abundant interfering components that co-elute with the target substances, especially if the concentrations of these substances are relatively low. In this study, we evaluated the possibility of expanding DDA coverag...