Pregnant Mares' Serum Gonadotropin (PMSG), also known as equine chorionic gonadotropin (eCG), is a hormone produced by the endometrial cups of pregnant mares. This hormone is primarily responsible for stimulating ovarian follicular development and supporting the formation of secondary corpora lutea during early gestation in horses. PMSG has both luteinizing and follicle-stimulating hormone activity, contributing to the maintenance of pregnancy. In veterinary and reproductive studies, PMSG is utilized to induce estrus and ovulation in various animal species due to its gonadotropic properties. This page compiles peer-reviewed research studies and scholarly articles that explore the biological function, application, and effects of Pregnant Mares' Serum Gonadotropin in equine reproduction and management.
Blodgett DJ.Most of the tall fescue pastures in the United States are infected by an endophyte, N. coenophialum. The fungus derives nutrients from the plant while supplying the plant with toxins for defense. The most detrimental toxins for animals in tall fescue are ergopeptine alkaloids, especially ergovaline. Ergovaline functions as a dopamine D2 agonist and alters prolactin and several other hormones in the body. Pregnant mares are most susceptible during their last month of gestation. Clinical signs include prolonged gestation, dystocia, retained placentas, agalactia, and dysmature foals that are eith...
Vollmar B, Laschke MW, Rohan R, Koenig J, Menger MD.To develop a model for the study of physiological angiogenesis, we transplanted ovarian follicles onto striated muscle tissue and analyzed the process of microvascularization in vivo using repeated fluorescence microscopy. Follicles were mechanically isolated from unstimulated as well as pregnant mare's serum gonadotropin (PMSG)- or PMSG/luteinizing hormone (LH)-stimulated Syrian golden hamster ovaries and were transplanted as free grafts into dorsal skinfold chambers of untreated or synchronized hamsters. Follicles lacking thecal cell layers did not vascularize regardless whether harvested fr...
Wooding FB, Morgan G, Fowden AL, Allen WR.Equine chorionic gonadotropin (eCG) production by the fetally derived endometrial cups appears to be necessary for the establishment and maintenance of normal equine pregnancy. Starting at about the 27th day of pregnancy, an equatorial band of trophectodermal cells on the surface of the spherical conceptus forms the chorionic girdle. This girdle consists initially of flat trophectodermal epithelium which corrugates into folds as the cells proliferate. The folds are then pressed against the uterine epithelium by expansion of the conceptus. The cells on the apices of the folds become binucleate ...
Allen WR.Four separate components combine to produce the progesterone and biologically active 5 alpha-reduced pregnanes needed to maintain pregnancy in the mare. The primary corpus luteum (CL) is prolonged beyond its cyclical lifespan by the down-regulation of endometrial oxytocin receptors to prevent activation of the luteolytic pathway and its waning progesterone production is supplemented from day 40 of gestation by the formation of a series of accessory CL which develop in the maternal ovaries as a result of the gonadotrophic actions of pituitary FSH and the equine chorionic gonadotrophin (eCG). Fr...
Marshall DE, Mortishire-Smith RJ, Houghton E, Gower DB.Oestradiene-3,17-diol and oestratriene-3,17-diol (or the diol of Heard's ketone (3-hydroxy-5(10),6,8-oestratriene-17-one) have been extracted on a large scale from pooled urines and allantoic fluid obtained from pregnant mares. Initial purification was achieved using column chromatography, and further purification by high performance liquid chromatography or silver nitrate (argentation) thin layer chromatography. The steroids were characterised using gas chromatography-mass spectrometry. Positions of the double bonds in ring B of oestradienediol were deduced on the basis of results of ultravio...
Watson ED, Thomson SR, Howie AF.A steroidogenic acute regulatory (StAR) protein has been identified in several species as a probable important rate-limiting step in steroidogenesis. This protein is believed to be responsible for transporting cholesterol from the outer to the inner mitochondrial membrane. It is known that equine chorionic gonadotrophin (eCG) stimulates steroidogenesis in the corpora lutea of early pregnant mares and that eCG also upregulates StAR mRNA in bovine ovaries. In the present study, ovarian tissue from cyclic and early pregnant mares was immunostained to detect the distribution of the StAR protein. W...
Ahlswede L.Future competition horses may suffer from health impairments due to complex or partial genetic components as well as to management faults in respects to keeping, feeding and health prophylaxis against infectious diseases. This health risks exist during the whole rearing period: from late pregnancy till far beyond weaning. Health impairments reduce trade value and practical use, and interfere with aspects of animal protection. In the field of breeding permission, first in stallions, applied research ist needed. For horse farms a praxis-oriented comprehensive advisory service should be establish...
Rodger FE, Illingworth PJ, Watson ED.Although the mare corpus luteum (CL) is capable of aromatization, the expression of other enzymes involved in estradiol synthesis is not yet clear. This study examined the localization of P450C17 in the mare CL at different stages of its functional development. In ovaries from follicular phase mares P450C17 was localized in the theca cells of ovarian follicles. Following ovulation, no immunostaining for P450C17 was detected in the mature CLs of nonpregnant mares. In pregnant mares, no immunostaining for P450C17 was identified in the corpus luteum prior to secretion of eCG by the feto placental...
Ohnuma K, Yokoo M, Ito K, Nambo Y, Miyake YI, Komatsu M, Takahashi J.Early pregnancy factor (EPF) is an immunosuppressive protein detected in the early pregnancy serum. We have already reported that we developed the rosette inhibition test for mare EPF and detected EPF in thoroughbreds. The aim of this study was to determine whether or not our method could be used clinically. Methods: The rosette inhibition test for equine EPF was carried out on serum from six nonpregnant and six pregnant Shetland ponies, a female and a male Chinese pony, and four nonpregnant and 13 pregnant thoroughbred mares. In the thoroughbreds sera were collected during the pregnancy perio...
Sechin A, Deschamps JC, Lucia T, Aleixo JA, Bordignon V.We evaluated the effect of PMSG on the weaning-to-first service interval, total litter size and born alive litter size in swine. Four doses of PMSG (0, 500, 750 and 1,000 IU) were administered intramuscularly after weaning to sows at 3 different farms, grouped by parities (1, 2 and 3 or higher) and 2 distinct time periods. The associations among main effects and response variables were assessed by analysis of variance. Polynomial orthogonal terms were used to adjust the estimates of weaning-to-first service interval, total litter size and born alive litter size for the interaction effect of pa...
Lagneaux D, Pomarici AM, Sattler M, Bruneau B, Duchamp G, Camillo F, Palmer E.Day 6.5 equine embryos (n=30) were frozen in a medium containing glycerol (2.5-10.0%) supplemented with 0, 20 or 100 mmol L-glutamine 1(-1). After thawing, the embryos were tested individually, using 4',6'-diamidino-2-phenylindole (DAPI) staining to evaluate cell death. Three embryos (one frozen at each L-glutamine concentration) were transferred together into individual recipient mares. Pregnancy diagnosis was performed at day 12 (age of embryo). Embryos were collected at day 14 (age of embryo) and were identified by PCR amplified microsatellite analysis. Nine of ten recipient mares that rece...
Witkowski M, Tischner M.The aim of the present study was to determine the effect of prolonged photoperiod during late pregnancy on subsequent ovarian activity and fertility in mares. Pregnant mares (n=13) due to give birth in January and February were stimulated by a fixed photoperiod (16 h light: 8 h dark) from 15 November (during the last 2-3 months of gestation) until up to 1 month after parturition. A control group of mares (n=9) due to give birth at the same time were kept in the same stable and management regimen, but under natural light conditions. Light-treated mares ovulated during foal oestrus approximately...
Henderson K, Stevens S, Bailey C, Hall G, Stewart J, Wards R.The relative merits of measuring blood concentrations of equine chorionic gonadotrophin (eCG, previously known as pregnant mare serum gonadotrophin (PMSG)), or oestrone sulphate (OS), or faecal OS concentrations for determining pregnancy status in miniature horses were investigated. Pregnant mares between 40 and 140 days after mating had serum eCG concentrations > 1 I.U. mL-1, with the highest concentrations occurring between days 50 and 120. However, eCG measurements were susceptible to returning a 'false positive' diagnosis of pregnancy. Plasma OS concentrations ranged from 0.1 to 3.6 ng ...
Freeman DE, Hungerford LL, Schaeffer D, Lock TF, Sertich PL, Baker GJ, Vaala WE, Johnston JK.Data from 116 mares that had caesarean section or vaginal delivery at 2 university hospitals were analysed in 5 groups, as follows: dystocia corrected by caesarean section, Group DCS (n = 48); elective caesarean section, Group ECS (n = 10); caesarean section concurrently with colic surgery, Group CCS (n = 8); assisted vaginal delivery, Group AVD (n = 22); and controlled vaginal delivery under general anaesthesia, Group CVD (n = 28). Survival rate in all mares that had caesarean section, excluding Group CCS, was 88% (51/58). All mares in Group ECS survived and Group CCS had the lowest survival ...
Sugawara Y, Yamanouchi K, Naito K, Tachi C, Tojo H, Sawasaki T.A cDNA clone encoding equine follistatin was isolated from an equine ovarian cDNA library. Out of 1.2 x 10(5) independent clones screened, one positive clone was isolated and its cDNA sequence determined. The isolated clone, named EQ-FS-1, contained a complete open reading frame encoding 344 amino acid residues. The similarity of its deduced amino acid sequence to these of other mammalian species was greater than 95%. Although its expression level varied among the tissues examined, follistatin mRNA was detected in the equine uteroplacental tissues, follicles and corpora lutea by Northern blot ...
González G, Castro B, Massaldi H.Equine chorionic gonadotrophin (eCG) is a hormone of practical value in veterinary medicine and animal production. Here we report a novel preparation procedure based on its direct adsorption onto anionic-exchange resins in a batch-wise mode. The active plasma is previously conditioned to reduce pH and ionic strength to required levels. After the adsorption stage, a 90% recovery of the initial eCG is achieved, with a concentration factor of about 50 and an enrichment factor around 500, with high preservation of biological activity. Further purification is carried out by cation-exchange column c...
Walker C, Perotti VM, Love DN, Whalley JM.The abortigenic effects of equine herpesvirus 1 (EHV-1) strain HVS25A, given intranasally, were assessed in pregnant BALB/c, C57BL/6J and Quakenbush mice at day 16 of pregnancy. All EHV-1-infected BALB/c mice showed clinical signs typical of EHV-1-induced disease, together with evidence of abortion. However, although there were fetal and neonatal deaths in some C57BL/6J and Quakenbush litters, the respiratory and systemic effects of EHV-1 infection in the dams were inconsistent. BALB/c dams were then inoculated at day 15 of pregnancy with either EHV-1 or rabbit kidney (RK) cell lysate (control...
Lantz KC, Enders AC, Liu IK.In addition to the unique feature of retention of unfertilized ova, the oviducts of mares frequently contain large intraluminal masses with a fibrillar component and some cells. The aim of this study was to identify the cells and examine their relationship to the extracellular components of these masses. Intraluminal masses were examined both in situ and flushed from the oviducts. The nature of the contained cells and their relationship to the fibrils were examined by light microscopy and by transmission and scanning electron microscopy. In some mares the large masses distended the oviduct, bu...
Cardwell BE, Fitch GQ, Geisert RD.Progestogens and follicular stimulants have proved reasonably successful for estrus synchronization, but time of ovulation relative to removal of the progestogen is not clearly established. We monitored time of ovulation in ewes following synchronized estrus. Ovaries of 40 Dorset and Rambouillet x Dorset ewes were evaluated during the spring and fall (20/replicate). Ewes were randomly assigned to one of two treatment groups (n = 20/group): implant-only (I) ewes received a norgestomet implant for 10 d; and implant + PMSG (PI) ewes received a norgestomet implant for 10 d with an i.m. injection o...
Knospe C.The aim of the study was to answer the open questions concerning the development of the horse's testis. This study revealed that the seminiferous tubules originate from the sex cords of the coelomic epithelium and Leydig cells from the proximal part of mesonephric nephrons, whereas the rete and the ductuli efferentes derive from intermediate and distal parts of the mesonephric tubules. During the development the Leydig cells undergo an enormous proliferation due to the PMSG secretion in the mare. The proliferation of these cells prevent the deep penetration of the rete into the medulla and is ...
Pearce SG, Grace ND, Wichtel JJ, Firth EC, Fennessy PF.Pregnant Thoroughbred mares (n = 21) were grazed on tall fescue pasture containing 4.4-8.6 mg Cu/kg dry matter (DM). Twelve mares were supplemented with approximately 0.5 mg Cu/kg liveweight (LW)/day as copper sulphate for the final 13-25 weeks gestation. Plasma copper concentration declined during the third trimester for all mares and was not affected by copper supplementation. Liver copper concentration of mares and foals was determined when the foals were 4-10-days-old. Copper supplementation of the mares tended to increase mare liver copper concentration (P<0.08) and increased foal live...
Goudet G, Leclercq L, Bézard J, Duchamp G, Guillaume D, Palmer E.This study reports the follicular growth and oocyte competence for in vitro maturation and fertilization under the influence of circulating eCG. Three to 7 successive ultrasound-guided follicular punctures were performed on 4 pregnant mares from Day 23 until Day 75 of pregnancy and on 5 control mares whose embryonic vesicle was crushed on Day 22. All follicles larger than 5 mm were punctured 24 h after the largest follicle reached 18 mm. Expanded cumulus oocyte complexes (COCs) were stained at recovery to analyze the nuclear stage. Compact COCs were cultured in vitro for 46 h and either staine...
Powell DG, Dwyer RM, Traub-Dargatz JL, Fulker RH, Whalen JW, Srinivasappa J, Acree WM, Chu HJ.To determine safety, immunogenicity, and efficacy of an inactivated equine rotavirus vaccine. Methods: Prospective randomized controlled trial. Methods: 316 pregnant Thoroughbred mares during the first year of the study and 311 during the second year. Methods: During the first year, mares received 3 doses of vaccine or placebo, IM, at 8, 9, and 10 months of gestation. Serum neutralizing antibody titers were measured before vaccination and 1 and 35 days after foaling. Antibody titers were measured in foals 1, 7, 35, 60, 90, and 120 days after birth. During the second year, mares that had been v...
Hurwitz A, Finci-Yeheskel Z, Milwidsky A, Yagel S, Adashi EY, Laufer N, Mayer M.To examine the participation of the theca-interstitial (TI) compartment in cytokine modulation of ovarian function, the effects of interleukin-1beta (IL-1) on plasminogen activator (PA) activity and on prostaglandin E (PGE) and nitric oxide (NO) production were examined in cultures of pregnant mare serum gonadotrophin (PMSG)-primed rat TI cells. Exposure to IL-1 (10 ng/ml) resulted in a 25% reduction (P < 0.001) in PA activity, concurrent with a 4.6-fold increase in the ability of the corresponding conditioned media to inhibit exogenous urokinase activity. IL-1 also produced a 4.7-fold incr...
Schulman M, Becker A, Ganswindt S, Guthrie A, Stout T, Ganswindt A.Validation of a method for the minimally-invasive measurement of physiological stress will help understanding of risk factors that may contribute to stress-associated events including recrudescence of Equid herpesvirus (EHV), which is anecdotally associated with sales consignment of pregnant Thoroughbred mares. In this study we compared two similar groups of late-gestation Thoroughbred broodmares on the same farm: a consigned Sales group (N = 8) and a non-consigned Control group (N = 6). The Sales mares were separated from their paddock companions and grouped prior to their preparation...
Hannan MA, Haneda S, Itami Y, Wachi S, Saitoh T, Cheong SH, Nambo Y.There has been no report of equine embryo transfer in Japan for the last 24 years. Our objective was to establish an effective protocol for embryo transfer in domestic horse. A Hokkaido native pony was bred by deep-horn artificial insemination with frozen semen from a Connemara pony. Embryo collection was performed using a non-surgical method on day 7. Two embryos were obtained from three flushes (67% recovery) and were transferred fresh into crossbred recipient mares. Both recipient mares were diagnosed pregnant (100% pregnancy rate) 5 days after embryo transfer and had normal progesterone le...
Combarnous Y, Hengé MH.A simple method of purification of equine follicle-stimulating hormone is described by which two forms of the hormone are obtained. The acid dissociation of the most active preparation was studied and a pKa of 5.8 was determined at 37 degrees C. This value is 2 pH units higher than that observed for pregnant mare serum gonadotropin suggesting that the binding areas between subunits are not identical in the two hormones. We also describe an homologous radioreceptor assay of equine follicle-stimulating hormone which is highly specific for this hormone in contrast to the heterologous systems desc...
Schams D, Papkoff H.Highly purified pregnant mare serum gonadotropin (PMSG) can be prepared from crude commercial preparations of PMSG by chromatography on sulfoethyl-Sephadex C-50 and gel filtration on Sephadex G-100. The preparation was examined by disc electrophoresis and gel filtration and found to be of high purity. Amino acid analysis shows similarities to pituitary gonadotropins. The PMSG contains a high content of proline and cystine and low amounts of the aromatic amino acids. Phenylalanine is the major amino terminal amino acid. The carbohydrate content totals 45% of which 10% is the content of sialic a...
Mitchell D, Allen WR.Reproductive performance was studied in 137 yearling mares run with stallions in small groups for 3 months between June and August in 1968 to 1971 (four breeding seasons). Pregnancy diagnosis by repeated rectal palpation and qualitative tests for PMSG, showed that ninety-five mares conceived of which forty-four aborted spontaneously between Days 30 and 160 of gestation. Laboratory examination of twenty-one aborted fetuses failed to show any infectious agents. Serial quantitative and qualitative tests for PMSG in aborting animals gave results similar to those observed in mares with normal pregn...
Terqui M, Palmer E.Plasma total (conjugated + unconjugated) oestrogens were measured from Day 0 to 100 of pregnancy and compared with the levels found during the oestrous cycle. From Day 0 to 35 of gestation, the concentrations were similar to those during dioestrus. An increase in total oestrogens between Days 35 and 40 was followed by a plateau of 3 ng/ml between Days 40 and 60 which was slightly higher than preovulatory concentrations. This first increase in total oestrogen level was produced by the ovaries since values were suppressed after ovariectomy; stimulation may be due indirectly to PMSG causing folli...
McDowell KJ, Webb BA, Williams NM, Donahue JM, Newman KE, Lindemann MD, Horohov DW.A new abortigenic disease, now known as mare reproductive loss syndrome (MRLS), significantly affected the horse industry in the Ohio River Valley of the United States in late April and early May of 2001 and 2002. In 2001, approximately 25% of all pregnant mares aborted within several weeks (over 3,000 mares lost pregnancies), and abortion rates exceeded 60% on some farms. Mare reproductive loss syndrome struck hard and without warning, it was caused by something in the environment, it was not transmitted between animals, and it was not associated with any known abortigenic agent or disease. T...
Gáspárdy A, Renkó E, Somoskői B, Bába A, Cseh S.The objective of this study was to compare the efficiency of artificial insemination (AI) carried out with frozen and fresh, diluted and chilled semen under field conditions. One hundred and twenty-nine mares of different breeds were included in the study. Eighty-one out of the 107 mares inseminated with fresh, chilled semen got pregnant. Seven pregnant mares aborted and 74 foals were born. Out of the 22 mares inseminated with frozen semen, 17 mares got pregnant. Two mares out of the 17 pregnant mares aborted and finally 15 healthy foals were born. No difference was found between the two group...
Palmer E.The use of photoperiod, progestagen, prostaglandin and hCG treatments was investigated to obtain mating of mares at predetermined times. The objectives were: (1) synchronization of oestrus at an early time of the year, (2) simplification of treatment schedules by use of vaginal sponges, and (3) use of several controlled cycles by successive synchronization. The following conclusions were reached. First, after a 16 h photoperiod was applied beginning on 25 November, hormonal synchronization of oestrus and ovulation followed by cyclicity were obtained on 1 February; i.e. 2 months of light are es...
Koskinen E, Kurki E, Katila T.Sixty-four mares (27 foaling, 37 barren or maiden), mainly Finnhorses, were subjected to treatment with 14.5 h of light and 9.5 h of darkness, starting at the beginning of December. The onset of cycling in non-foaling mares was estimated by weekly serum progesterone determinations. All of the non-foaling mares cycled in the middle of March. They started to cycle on average in the middle of February, 11.1 weeks after the beginning of the trial. There were statistically significant differences in relation to breed (Finnhorses started to cycle 2 weeks later than warm blooded, p less than 0.02) an...
Chavatte-Palmer P, Derisoud E, Robles M.Horses have been domesticated by man and historical information mostly associates horses with men. Nowadays, however, horse riding is essentially by women. Women are also very much involved in equine sciences, with a large contribution to the understanding of fetoplacental development. While highlighting the work of female scientists, this review describes the recent advances in equine fetoplacental studies, focusing on data obtained by new generation sequencing and progress on the understanding of the role of placental progesterone metabolites throughout gestation. A second emphasis is made o...
Keiper R, Houpt K.The reproductive rate and foal survival of the free-ranging ponies on Assateague Island National Seashore were studied for 8 years, 1975 to 1982. Most (52%) of the 86 foals were born in May, 13% were born in April, 22.6% in June, 10.4% in July, and less than 1% in August and September. The mean foaling rate was 57.1 +/- 3.9% and the survival rate was 88.3 +/- 3.6%. Forty-eight colts and 55 fillies were born (sex ratio 53% female). Mares less than 3 years old did not foal and the foaling rate of 3-year-old mares was only 23%, that of 4-year-old mares was 46%, that of 5-year-old mares was 53%, a...
Fowden AL, Ralph MM, Silver M.Prostaglandins (PGs) are produced by a variety of uteroplacental tissues during pregnancy and are released into the fetal fluid sacs and both the uterine and umbilical circulations. Uterine PG output increases towards term and is enhanced by maternal undernutrition in pregnant ewes and mares. In both species, withdrawal of food but not water for 30-48 h increases uterine venous PG levels and the uterine venous arterial concentration differences in PGE and 13, 14, dihydro-15-keto-prostaglandin F2 alpha (PGFM), the stable metabolite of PGF2 alpha. The increments in uterine V-A concentration diff...
Murchie TA, Macpherson ML, LeBlanc MM, Luznar S, Vickroy TW.Most current treatments for placentitis in mares are empirical with few control studies to evaluate their effectiveness. Objective: To monitor drug concentrations in allantoic fluid of pregnant pony mares using in vivo microdialysis and establish if this method would be useful for determining allantoic concentrations of drugs in normal mares and those with placentitis. Methods: Five late gestational pony mares had microdialysis probes inserted into the allantoic fluid using transabdominal ultrasound-guided allantocentesis. Single injections of penicillin G (22,000 u/kg), gentamicin (6.6 mg/kg ...
Taylor PM, White KL, Fowden AL, Giussani DA, Bloomfield M, Sear JW.To characterize propofol anaesthesia in pregnant ponies. Methods: Fourteen pony mares, at 256 ± 49 days gestation, undergoing abdominal surgery to implant fetal and maternal vascular catheters. Methods: Pre-anaesthetic medication with intravenous (IV) acepromazine (20 µg kg), butorphanol (20 µg kg) and detomidine (10 µg kg) was given 30 minutes before induction of anaesthesia with detomidine (10 µg kg) and ketamine (2 mg kg) IV Maternal arterial blood pressure was recorded (facial artery) throughout anaesthesia. Arterial blood gas values and plasma concentrations of glucose, lactate, cort...
Taylor PM, Silver M, Fowden AL.The uterine and umbilical vessels of 12 pregnant ponies were catheterised to study foetal metabolism. The effects of this procedure on maternal and foetal cardiovascular, respiratory, metabolic and adrenocortical activity were monitored during and after surgery. Premedication with acepromazine-butorphanol-detomidine was followed by induction of anaesthesia with detomidine and ketamine and maintenance, using mechanical ventilation, with halothane in oxygen and nitrous oxide. Mean maternal arterial blood pressure was greater than 70 mmHg during anaesthesia and arterial oxygen tension remained ov...
Pinto CRF.It has been more than a hundred years that studies aiming to elucidate the processes involved in cyclicity and pregnancy pointed out the requirement of ovaries and corpora lutea for embryo survival and pregnancy establishment. For horses, luteal progesterone is essential for pregnancy only during the first trimester. This progestational support is complex among domestic animals as ovarian luteal function is further enhanced by the LH-action role of equine chorionic gonadotropin (eCG) starting ∼ on Day 35 of pregnancy. Increased eCG secretion leads to the formation of supplementary corpora ...
Ware VC.In an attempt to understand more fully processes that control the selection or recruitment of follicles for ovulation, the superovulation paradigm in combination with the androgen, 5 alpha-dihydrotestosterone, or the antiandrogens, cyproterone or cyproterone acetate, was used in the immature mouse to alter the developmental potential of follicles destined to ovulate or to become atretic. Quantitative analysis of the numbers of eggs ovulated after one or more rounds of stimulation by pregnant mare's serum gonadotrophin followed by human chorionic gonadotrophin (PMSG-hCG), revealed a dose-depend...
Gospodarowicz D.A highly purified preparation of PMSG has been obtained from fresh serum and from a commercial preparation. Carbohydrate and amino acid compositions have been determined. The carbohydrate content of PMSG is 46.7% and the molecule is rich in Sialic Acid (13.5%). The apparent molecular weight of PMSG has been determined by SDS polyacrylamide gel electrophoresis. A molecular weight of 53,000 has been found for the unreduced and unalkylated molecule. After reduction and alkylation, the molecular weight fell to 23,000. From these values it has been concluded that PMSG is an oligomeric molecule comp...
Kormann DC, Locatelli-Dittrich R, Richartz RR, Antunes J, Dittrich JR, Patrício LF.In order to evaluate the seroprevalence and the dynamic of anti-Neospora antibodies in pregnant mares, serum samples from 14 animals in the 8th, 9th, 10th and 11th month of pregnancy were analyzed using indirect immunofluorescense technique. Samples diluted 1:50 showed higher seroprevalence on the 8th month (57%) and higher seropositive conversion on the 10th month. 85,7% of the mares were positive for Neospora sp. on at least one month of pregnancy, and seven from that total were positive on the 11th month, three of which showed the highest titles of 1:200 and 1:400. For the samples diluted 1...
Hillensjö T, Bauminger S, Ahrén K.Preovulatory follicles were explanted on the day before ovulation from immature rats given a single injection of Pregnant Mare's Serum gonadotropin (PMS) 2 days earlier. The follicles were incubated for 4 h in modified Krebs bicarbonate buffer containing glucose and albumin in absence or presence of ovine luteinizing hormone (NIH-LH-S18; 0.1-10 mug/ml). The accumulation of progresterone, androstenedione and 17beta-estradiol in the medium was determined by radioimmunoassay. As in indicator of LH exposure the meiotic stage of the follicle-enclosed oocyte was determined at recovery by interferenc...
Gospodarowicz D, Papkoff H.A simple procedure is described for the purification of pregnant mare serum gonadotropin (PMSG). The purification of PMSG from serum employed pH fractionation with metaphosphoric acid, alcohol precipitation, gel-filtration on Sephadex G-100, and chromatography on sulfoethyl-Sephadex C-50. The specific activity of the final product averaged 15,800 IU/mg and was obtained in yields of 50-80% of the activity initially present in unfractionated serum. The preparation obtained by this procedure has been characterized with respect to biological activity, electrophoresis on columns of polyacrylamide, ...
SAVARD K.The urinary ketonic estrogens were studied at monthly intervals in five pregnant mares. Estrone and equilin appear to be the principal components and equilenin a minor constituent of the mares’ estrogens. The levels of equilin rise from the 4–5th months to equal and in some instances exceed those of estrone in the late months of pregnancy. A partition chromatographic method for the separation of the ketonic phenolic steroids of pregnant mares’ urine is described.
Filipović N, Stojević Z, Prvanović N, Tucek Z.Pregnancy and lactation are periods of significant influence on bone metabolism that has not been investigated in equines. To examine the influence of late pregnancy and lactation on bone metabolism in mares, the changes in the blood serum/plasma total calcium (Ca), inorganic phosphates (Pi), pyridinoline (Pyd) and 17beta-estradiol (E2) concentration and the bone alkaline phosphatase (BAP) activity were investigated. The samples were taken from 11 mares on 60+/-10 and 20+/-10 days before foaling, and 20+/-10 and 60+/-10 days after foaling. The concentration/activity of Ca, Pi, Pyd and BAP incr...
Sielhorst J, Roggel-Buecker U, Neudeck KC, Kahler A, Rohn K, Luettgenau J, Bollwein H, Hollinshead F, Sieme H.The aim of this double-blinded placebo-controlled study was to investigate the effect of acetylsalicylic acid (ASA) on uterine blood flow, gestation length, placental and foal weights in pregnant mares. Sixteen Thoroughbred mares of different age (13.3 ± 4.1) and parity (7.4 ± 3.1) were randomly assigned to three treatment groups. Mares in group C (n = 4) served as controls and received 5,000 mg lactose orally once daily from D 120 (D 0 = day of ovulation) until parturition. Mares in group ASA1 (n = 7) received 5,000 mg ASA orally once daily from D 120 until parturition. Mares in group...
Beachler TM, Gracz HS, Morgan DR, Bembenek Bailey SA, Borst L, Ellis KE, Von Dollen KA, Lyle SK, Nebel A, Andrews NC, Koipalli J, Gadsby JE, Bailey CS.Metabolomics may represent an avenue for diagnosis of equine ascending placentitis. Objective: To characterise the plasma metabolomic profile in healthy mares and mares with induced ascending placentitis, with the goal of identifying metabolites with potential clinical value for early diagnosis of placentitis. Methods: Controlled in vivo experiment. Methods: Placentitis was induced in 10 late-term pregnant pony mares via Streptococcal equi subsp. zooepidemicus inoculation in five mares between days 285 and 290 of gestation, while five mares served as healthy controls. Repeated ultrasound exami...
Wilson CA, ter Haar MB, Bonney RC, Buckingham J, Dixson AF, Yeo T.We have shown previously that pregnant mare serum gonadotrophin (PMSG) induces ovulation only in rats weighing over 60 g on the day of injection. The under-60 g rats do not ovulate although they secrete a preovulatory surge of a pleiomorphic form of LH. Presumably this pleiomorph is inactive. Comparisons were made of plasma hormone concentrations in rats treated with PMSG that weighed over and under 60 g. The measurements were made on samples taken between 13.00 and 22.00 h on the day of the expected preovulatory LH surge. Prolactin and corticosterone levels were lower in the lighter group com...
