Hormones in horses are chemical messengers produced by various glands and tissues, regulating numerous physiological processes essential for maintaining homeostasis. These hormones influence a wide range of functions, including growth, metabolism, reproduction, and stress responses. Key hormones in equine physiology include cortisol, estrogen, testosterone, and insulin, among others. The levels and effects of these hormones can vary based on factors such as age, sex, and environmental conditions, impacting overall health and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the production, regulation, and physiological roles of hormones in equine biology.
Cox JE, Jawad NM.The authors describe the short and long term effects of synthetic adrenocorticotrophin and of cortisol on peripheral plasma testosterone concentrations in 2 stallions. A single injection of either hormone temporarily raised plasma testosterone concentrations but repeated injection (twice daily for 5 days) depressed plasma testosterone concentrations. Cessation of treatment was followed by a rise in plasma testosterone to concentrations higher than those in the pretreatment period. These findings are briefly discussed.
Foster JP, Evans MJ, Irvine CH.Mares at different stages of the oestrous cycle were given a single intravenous injection of 0.5 mg synthetic Gn-RH. The mean area of the induced LH peak was significantly less at mid-cycle (Day 10-11) than at any other time. The mean height of the LH peak above preinjection concentration was greater at late oestrus and early cycle (Day 5-6) than at mid-cycle and early oestrus. There were no significant different in mean FSH responses. The LH:FSH ratio for both height and area of induced peaks was significantly less at mid-cycle than at other times of injection. These results suggest that one ...
Taverne MA, van der Weyden GC, Fontijne P, Dieleman SJ, Pashen RL, Allen WR.Uterine electromyography was performed by means of chronically implanted surface electrodes in 3 Pony mares during spontaneous oestrous cycles and following luteolysis induced by a prostaglandin analogue (fluprostenol). Three distinct patterns were recognized during the oestrous cycle. (1) During oestrus well defined phases of activity with closely grouped high-amplitude spikes were separated by long periods (10-45 min) of complete inactivity. (2) During dioestrus more diffuse phases of activity with low-amplitude spikes were separated by variable periods of relative inactivity. (3) During lut...
Wesson JA, Orr EL, Quay WB, Ginther OJ.Pony pineal glands and female reproductive tracts were collected monthly for 1 year from
a local slaughterhouse. Pineal gland weights did not change significantly throughout the year.
Pineal gland tissue homogenates were assayed for hydroxyindole-O-methyltransferase
(HIOMT) activity with N-acetylserotonin as the primary substrate. The greatest HIOMT
activity was obtained with N-acetylserotonin as substrate. but three other related S-OH
indole substrates (5-hydroxytryptophol, serotonin. and 5-hydroxy-2-methylindole) were also
methylated. HIOMT activity with all substrates was highest duri...
Eiler H, Goble D, Oliver J.The plasma concentration of hydrocortisone was determined in mares given either cosyntropin (100 IU, given IV) or corticotropin (200 IU, given IM). Plasma hydrocortisone concentrations of the mares treated with cosyntropin increased by 46%, 57% and 80% at 30, 60, and 120 minutes, respectively, when compared with base-line values; these values returned to base line at 240 minutes. In mares treated with corticotropin, mean plasma hydrocortisone concentrations increased by 42%, 143%, 101% and 155% at 30, 60, 120, and 240 minutes, respectively, when compared with base-line values. Differences in t...
Neely DP, Stabenfeldt GH, Kindahl H, Hughes JP, Kendrick JW.The intrauterine infusion of 500 ml of warm sterile saline solution into mares on days 12, 13, or 14 after ovulation failed to alter the ovulatory interval, although intervals were shorter for days 12 and 13 (20.6 days) when compared with those in control mares (21.6 days). The IU fusion shortened luteal-life-span on days 12 (12.0 vs 13.8 days) and 13 (13.0 vs 14.4 days) (P is less than 0.05), but not day 14 (14.0 vs 13.5 days), when comparing the effects of IU infusion with an average of before and after base-line data. There was no effect on the interval from corpus luteum regression to ovul...
Sharp DC, Garcia MC, Ginther OJ.Luteinizing hormone (LH) was quantified in pony mares during artificially induced sexual maturation. Ovarian follicular development was also assessed by rectal palpation of the ovaries. With the exception of large periovulatory LH concentrations in two mares that ovulated, LH concentrations were not significantly different in mares undergoing sexual maturation and thus having marked follicular development when compared with mares that were not undergoing sexual maturation and thus did not have marked follicular development. These results indicate a dissociation in time between the onset of fol...
Neely DP, Stabenfeldt GH, Sauter CL.Daily injections of 150 units oxytocin administered to 6 mares on Days 4, 5, 6, 7 and 8 after ovulation (Day 0 = ovulation) failed to induced luteolysis as indicated by the maintenance of normal plasma progestagen concentrations and the occurrence of normal ovulatory intervals. Three additional mares were given oestrogen injections 24 h before an injection of oxytocin on Day 7 after ovulation, but this treatment also failed to induce luteolysis since plasma progestagen concentrations were maintained in all three mares. Two mares exhibited normal ovulatory intervals, while the third developed a...
Moore JN, Steiss J, Nicholson WE, Orth DN.In the horse, a syndrome of hirsutism, hyperglycemia, glucosuria, polydipsia, polyuria, polyphagia, and progressive debilitation has been recognized. Most often the syndrome has been associated with adenomas of the pars intermedia of the pituitary and bilateral adrenal hyperplasia or nodular hyperplasia involving primarily the zona fasciculata. Previously, the syndrome has been ascribed to compression of the hypothalamus by an expanding but functionally inactive pituitary neoplasm. In the present case, with RIA determination of plasma ACTH concentrations, the syndrome was ascribed to pituitary...
Menzer C, Schams D.A double-antibody radioimmunoassay for PMSG, especially for meauring PMSG in cattle blood after exogenous application, has been developed. A rabbit antiserum against PMSG and pure PMSG for radioiodination were used. There was a strong cross-reaction against equine LH and FSH, but the slight cross-reaction against bovine LH and FSH could be eliminated by adding bovine LH to each tube during the assay. Unspecific, interfering influences of equine or cow serum could be eliminated by adding a constant amount of PMSG-free serum to each tube. PMSG added to 200 microliter of serum could be recovered ...
Allen WE.The situations and conditions that can disrupt the mares normal oestrous cycle are described. Season of the year is a major influence; maximum reproductive efficiency does not totally coincide with the artificially defined "breeding season". Other abnormalities are associated with spontaneously persistent luteal function, psychological influences over behavioural activity, the presence of endometritis, multiple ovulation, reproductive behavior after pregnancy failure and granulosa cell tumours.
Zavy JT, Mayer R, Vernon MW, Bazer FW, Sharp DC.Uterine flushings were collected from 30 non-pregnant Pony mares on Days 8, 12, 14, 16, 18 or 20 after oculation. Mares were allowed a recovery period of one oestrous cycle and were mated at the next oestrus. They were then ovario-hysterectomized on days which corresponded to the day of the oestrous cycle to which they were assigned. Uterine flushings were analysed for total recoverable protein and acid phosphatase activity. Least squares analysis indicated a status X day interaction for total protein (P less than 0.10) and acid phosphatase activity (P less than 0.005) in which the latter was ...
Garcia MC, Freedman LJ, Ginther OJ.A working hypothesis for the regulation of LH secretion in the mare is postulated which involves the following two components: (1) a primary central nervous system (CNS)-pituitary component which is responsible for a basal circannual LH rhythm, entrained to an environmental 'Zeitgeber' (most probably photoperiod) and independent of ovarian influences, and (2) a secondary ovarian (steroidal) component which modifies the primary rhythm during the ovulatory season. This hypothesis does not seem to apply in its entirety to FSH secretion; the CNS-pituitary component is demonstrable within the first...
Larsson M, Edqvist LE, Ekman L, Persson S.Peripheral blood plasma Cortisol concentration and its diurnal variation was measured in 4 horses. Mean concentration of Cortisol during 24 hrs. was 42 ng/ml (s ± 20 ng/ml). Peak values occurred at 6 a.m. and the lowest values were observed at about 6 p.m. (mean 65 ng/ml and 20 ng/ml, respectively). Long-acting ACTH at a dose of 150 i.u. was given by intramuscular injection to the 4 horses. Peak Cortisol concentrations markedly exceeding the prestimulation level were obtained between 2 and 4 hrs. after injection. During the immediate 24 hrs. after these peaks, the mean Cortisol level was mark...
Vivrette SL, Irvine CH.Acyclic mare given oestradiol for 3 days to simulate the preovulatory plasma oestradiol surge showed a non-significant 37% decrease in plasma LH during treatment. When GnRH analogue injections were given with oestradiol on Days 1--3, oestradiol had no effect on each GnRH-induced LH increase, but LH increases were more prolonged following subsequent GnRH injections on Days 4--7 when oestradiol was no longer being given. A much greater prolongation of LH release occurred when the course of GnRH injections was commenced after oestradiol treatment ceased; the LH response was almost identical to th...
Raeside JI, Liptrap RM, McDonell WN, Milne FJ.Plasma levels of total oestrogens and dehydroepiandrosterone (DHA) were measured by radioimmunossay in samples taken from various blood vessels in both maternal and fetal compartments in 11 Pony mates. High concentrations of oestrogens (greater than 100 ng/ml of plasma), expressed as oestrone equivalents, were found in the fetal circulation. On both the fetal and maternal sides, oestrogen concentrations were lower in blood going to than from the placenta. DHA concentrations, on the other hand, were higher in blood flowing to the placenta from the fetus. The fetal gonads were seen as the source...
Zarrilli A, Lacalandra GM, Minoia P.In mare, sheep and bitch the action of PGF2 alpha have been studied in the early pregnancy. Prostin F2 alpha (Upjohn) and Gabbrostim (Vetem ) are commercial names of PGF2 alpha used at doses which are luteolytic in the non pregnant female. Seric progesterone showed a temporaneous decrease but after four or five days the initial values were restored and none of the experimental females aborted. In the opinion of authors, embryo per se and/or with its adnexa might have interacted blocking the mechanism of luteolysis induced by the administration of PGF2 alpha.
Cox JE, Redhead PH.The long term effect of a single injection of 6,000 iu of human chorionic gonadotrophin (hCG) was studied in two pony stallions. Peripheral plasma samples were analysed for testosterone and oestrone sulphate. Testosterone concentrations were markedly elevated for five days after injection in both stallions. No adverse effects of these high concentrations were observed on concentrations later in the experiment. There was an initial increase in oestrone sulphate in one stallion, after which concentrations decreased to below pre-injection levels. The other stallion (whose initial oestrone sulphat...
Legacki EL, Bal BA, Corbin CJ, Loux SC, Scoggin KE, Stanley SD, Conley AJ.The authors apologize for errors in Figure 6 of their article published in the October 2017 issue of Reproduction (vol 154 iss 4 pp 445–454). The authors explain that the addition of data (Figure 6) on steroid concentrations in the chorioallantois to their manuscript on fetal adrenal and fetal gonadal steroids during development of the equine fetus was made in response to reviewer comments. However, in compiling, summarizing and graphing the data, the wrong units were used in the final figure. The manuscript as published represents the data in Figure 6 as “ng/g”, when in fact they are ...
Sharma OP.The concentrations of PGF-2alpha in the peripheral blood of five foaling mares were measured by radioimmunoassay. Low levels of PGF-2alpha were detected as early as 1 week before foaling in two of the mares. These levels increased steadily, reaching a peak (1-74 +/- 0-44 ng/ml) during fetal expulsion. A relatively high PGF-2alpha level was found in samples collected 60 min after foaling.
Rivero JL, Cascone O, Biscoglio de Jimenez Bonino MJ.1. The method of Kubota et al. [Biochim. biophys. Acta 701, 242-252 (1982)] was applied to several members of the growth hormone family in order to examine their conformational homology. 2. The method neither detects differences between rat, cow, sheep, horse and alpaca hormones, nor between monkey and human hormones. 3. Lack of homology between primate and non-primate growth hormones was found in segments 42-49 and 184-191. The first fragment could be linked to species-specificity.
Saint-Dizier M, Foulon-Gauze F, Lecompte F, Combarnous Y, Chopineau M.In order to investigate the role of the unique seventh N23-glycosylation site of the equine LH/CG receptor (eLHCGR) in the cAMP pathway activation, COS-7 cells were transiently transfected with either the wild-type or the mutant eLHCGR(N23Q) cDNA and challenged with porcine LH and eCG for cAMP production. We showed that the N23-glycosylation site of the eLHCGR is not required for the functional coupling of the receptor with the cAMP pathway and is not responsible for the limited potency of eCG relative to pLH to activate this receptor.
Rizzo A, Mutinati M, Spedicato M, Minoia G, Trisolini C, Punzi S, Roscino MT, Jirillo F, Sciorsci R.The beta-subunits of thyroid stimulating hormone (TSH) and human chorionic gonadotropin (hCG) share a high homology, just like the ectodomains of their receptors, do. As a consequence, hCG was shown to exert a thyrotropic action in humans and hamsters. This study aimed to investigate whether hCG, used to induce ovulation, displays a thyrotropic effect in the equine species too. Forty mares at estrus were divided in two groups; 20 were intravenously treated with sterile saline solution (NaCl 0.9%) (group A); 20 were intravenously treated with 4000 I.U. of hCG (group B). All the mares were artif...
Pal AK, Gupta T, Chatterjee A.A single consistent luteolytic dose of 10 IU PMSG given on day 5 of pregnancy caused complete resorption of foetuses and placentae associated with a polyfollicular ovarian state in rats. Concomitant treatment with progesterone or prolactin given concurrently with PMSG was found to overcome the antifertility efficacy of PMSG and maintained the endocrine balance favouring pregnancy maintenance. It was postulated that the PMSG-induced ovarian polyfolliculogenesis might be responsible for luteolysis of the corpus luteum gravidarum.
al-Timimi I, Gaillard JL, Amri H, Silberzahn P.Whereas mare corpus luteum does not produce androgens or estrogens in vivo, the incubation of mare corpus luteum microsomes with progesterone and NADPH resulted in 17 alpha-hydroxyprogesterone and estrogen production with a small yield of androstenedione. In the presence of an aromatase inhibitor (4-hydroxyandrostenedione), 17 alpha-hydroxyprogesterone and androstenedione were accumulated. Aromatization of testosterone and androstenedione occurred via stereospecific loss of the 1 beta, 2 beta hydrogen atoms and was inhibited by MgCl2, KCl, and EDTA. The Km of estrogen synthetase from equine co...
Colquhoun KM, Eckersall PD, Renton JP, Douglas TA.Six mares were studied over a period of two years under varying conditions of lighting from total darkness to normal ambient lighting. The mares continued to cycle during the winter under natural lighting and also when kept in total darkness. Circulating melatonin, progesterone and oestrogen concentrations were determined and related to clinical changes in the reproductive tract.
Mozzaquatro FD, Verstegen JP, Douglas RH, Troedsson MH, DeLaCorte FD, Silva CA, Rubin MI.Ultrasonic-guided transvaginal follicle aspiration was performed in 58 crossbreed mares in order to determine whether aspiration of various dominant follicle diameters resulted in luteal tissue capable of producing progesterone (P(4)). The mares were randomly assigned to three groups according to follicular diameter (25-29 mm; 30-35 mm and >35 mm). Mares that had ovulations naturally served as controls. The serum progesterone (P(4)) concentrations in the aspirated mares were greater (P < 0.0001; r(2) = 0.6687; CV = 21.52) in mares with natural ovulation compared to mares with aspirated follicl...
Nádasdi L, Yamashiro D, Li CH, Izdebski J.Five analogs of equine β-melanotropin have been synthesized by the solid phase method. The NH2-terminal aspartic acid was substituted with amino acids (Gly, Trp, Ile, Lys and Nα-acetyl-Asp) differing widely in physicochemical properties. On the basis of their lipolytic potencies it was concluded that this position plays a negligible role in this activity.
Skrabalak DS, Maylin GA.Dexamethasone and a metabolite, 9-fluoro-16α-methyl-6β, 11β, 16β-trihydroxy-1, 4-androstadiene-3, 17-dione, were detected in the urine of horses injected parenterally with the parent drug. The structure of the metabolite was elucidated by thin-layer chromatography, infrared spectroscopy, mass spectroscopy and nuclear magnetic resonance spectroscopy.
Bedford SJ, Hinrichs K.It has recently been reported that large insemination volumes might affect fertility of mares. The results from these studies are confounded by other factors, however, such as inadequate number of spermatozoa in the inseminate. We conducted a study to test whether volume alone affects fertility when sufficient numbers of spermatozoa are present. Semen from one stallion was collected, extended at 50 x 10(6) spermatozoa/ml, and stored in a commercial semen cooling device for 18 to 30 h before insemination. Ten pony mares were assigned during estrus in random pairs to be bred every other day with...
Dumasia MC, Houghton E.The research investigates the biosynthesis of a particular isomer called 5(10)-estrene-3 alpha, 17 beta-diol in stallion testes and how it affects the formation of 19-nor steroids and oestrogens. Summary of […]
Carnevale EM, Squires EL, Maclellan LJ, Alvarenga MA, Scott TJ.In some mares with lesions of the reproductive tract, embryo collection and survival rates are low, or collection of embryos is not feasible. For these mares, oocyte transfer has been proposed as a method to induce pregnancies. In this report, a method for oocyte transfer in mares and results of oocyte transfer performed over 2 breeding seasons, using mares with long histories of subfertility and various reproductive lesions, are described. Human chorionic gonadotropin or an implant containing a gonadotropin-releasing hormone analog was used to initiate follicular and oocyte maturation. Oocyte...
Stabenfeldt GH, Hughes JP, Wheat JD, Evans JW, Kennedy PC, Cupps PT.The effect of hysterectomy on ovarian activity was studied
in four mares. The cyclic secretion pattern of plasma progestins normally
observed in the intact mare was interrupted by hysterectomy. Follicular
activity was observed in all four hysterectomized mares, in spite of pro-
longed luteal activity, with a large number of follicles attaining ovulatory
size without the occurrence of ovulation. Some ovulations were observed
at irregular intervals in two out of four hysterectomized mares in spite
of plasma progestin levels which ranged from 2 to 6 ng/ml. While all
ovulations which occur...
Ginther OJ, Pinaffi FL, Rodriguez MB, Duarte LF, Beg MA.During the luteolytic period in mares, the peak of 65% of pulses of a PGF2α metabolite (PGFM) and the peak of a pulse of PRL have been reported to occur at the same hour. It is unknown whether the synchrony reflects an effect of PGF2α on PRL or vice versa. Controls, a flunixin meglumine (FM)-treated group (to inhibit PGF2α), and a bromocriptine-treated group (to inhibit PRL), were used at 14 days postovulation in June and in September (n = 6 mares/group/mo). Blood samples were collected hourly from just before treatment (Hour 0) to Hour 10. Concentrations of PGFM in the FM group were lower ...
Shand N, Alexander SL, Irvine CH.For aqueous extracts of pituitary glands of oestrous mares, luteinizing hormone (LH) profiles were found to be similar to each other and to earlier work after chromatofocussing (CF) and isoelectricfocussing (IEF). After CF, both LH and follicle-stimulating hormone (FSH) in pituitary extracts focussed in multiple peaks in the acidic range, with 86% of LH and 80% of FSH found between pH 4 and 6. By contrast, in pituitary venous plasma, only 18% of the LH focussed in this range, whereas a significantly greater proportion (P less than 0.01) eluted above pH 7 than occurred in pituitary extracts (37...
Purcell SH, Seidel GE, McCue PM, Squires EL.The aim of this study was to compare the efficacy of three approaches for recovering equine oocytes via transvaginal ultrasound-guided follicular aspiration. Fourteen mares were used as oocyte donors during the spring transition period and physiologic breeding season, and 11 mares were bred for use as oocyte donors during early gestation. In all mares, large (>20 mm) and small (10-20 mm) follicles were aspirated in eight rounds every 10-11 days. In each of the four rounds during the transition period, half the mares received 12.5 mg eFSH once daily for 4 days prior to aspiration. For each of t...
Rossdale PD, McGladdery AJ, Ousey JC, Holdstock N, Grainger L, Houghton E.Maternal plasma progestagen concentrations increase about 20 days before parturition. The major contributors to the increase are reduced metabolites (ie 5 alpha-pregnanes). Precocious increases (ie less than 310 days of gestation) in these metabolites may occur in abnormal pregnancies. The effects of CRH, ACTH or betamethasone administered to the foetus at gestational ages ranging from about 250 to 320 days were examined. Sixteen healthy pony mares were used for foetal injection employing aseptic techniques. Water or normal saline were used as controls. Maternal plasma progestagen concentratio...
Scanlon PF.Thirteen cows (8 Holsteins, 3 Ayrshire,
2 Shorthorn; 3 to 7 years old) were
treated with pregnant mare serum gonadotrophin (PMSG) during two successive
estrous cycles. The gonadotrophin was
injected on Day 16 of the cycle (estrus ---
Day 0) and again on Day 16 of the next
cycle (10 cows) or 21 days after previous
PMSG injection (3 cows). Doses of
PMSG injected during the first cycle were
3,000 IU (6 cows: Group A) and 2,000
IU (7 cows: Group B). These doses were
reversed for the individual cow during
its next estrous cycle. Cows were
slaughtered 10 to 14 days after the second
PMS...
Jeffcott LB, Hyland JH, MacLean AA, Dyke T, Robertson-Smith G.Pregnant Standardbred mares were allocated to 2 groups. On Day 45 of gestation, 20-45 ml saline (240 g NaCl/l) were injected into the fetal sacs of 10 mares, and the other 10 mares were given sham treatment. Post-operative plasma oestrone sulphate concentrations were lower (P less than 0.01) on Days 48-55 in saline-treated mares than in sham-treated mares. Mean plasma progesterone profiles were similar in the two groups of mares, although post-operative luteolysis occurred in 4 saline-treated mares. There was no difference in plasma CG profiles between the 2 groups, except that CG concentratio...
Hillman RB, Loy RG.The rate of urinary oestrogen excretion was studied in four ovariectomized mares. In two animals ovariectomized when urinary oestrogen concentration was high, levels fell to a minimun within 48 hr. Intramuscular injection of oestradiol-17beta produced maximum urinary oestrogen levels within 3 to 6 hr and a return to minimum detectable levels within 24 hr. The major urinary oestrogen in mares was oestrone. In nine maiden mares studied between September and June, the cycle, the durations of dioestrus and oestrus, and the time of ovulation were similar in autumn (September to December) and spring...
Roser JF, Lofstedt RM.Blood and urine samples collected from 12 mares at frequent intervals from 25 to 210 d of pregnancy were analyzed for equine chorionic gonadotropin (eCG). Blood and urine samples were collected daily through two consecutive ovulatory periods from five cyclic mares for comparative purposes. Separate radioimmunoassays (RIA) were developed to detect eCG in the urine and plasma. A simple and quick commercial dipstick enzyme-linked immunospecific assay (ELISA), developed for eCG in the blood, was also utilized in this study to detect eCG in the urine. In the 12 pregnant mares, eCG concentrations in...
Douglas RH, Del Campo MR, Ginther OJ.On the day of ovulation (Day 0), 20 pony mares were randomly assigned to one of five groups (4 mares/group) which were given intracarotid arterial (ICA) and intraovarian arterial (IOA) injections on Day 7 as follows: 1) vehicle ICA, vehicle IOA (control); 2) .125 mg PGF2α ICA, vehicle IOA; 3) vehicle ICA, .125 mg PGF2α IOA; 4) .250 mg PGF2α ICA, vehicle IOA; or 5) vehicle ICA, .250 mg PGF2α IOA. Peripheral plasma progesterone and LH concentrations were determined for 0 (pretreatment) and .1, .25, .50, .75, 1, 6, 12, 24, 48, 72 and 96 h posttreatment. The intervals (days) from treatment to ...
Rance TA, Park BK.Oestrone, equilin and dehydroepiandrosterone were measured by radioimmunoassay in peripheral plasma from five pony mares; samples were taken from day 60 of pregnancy at approximately weekly intervals through to parturition. Of the three steroids measured, dehydroepiandrosterone showed the most consistent pattern of secretion. DHA concentrations remained low until day 105, increased rapidly from day 120 and attained maximum values between days 168–210; levels declined to day 300, but there was considerable variation between mares in DHA patterns prior to parturition. There was great variation...
van der Linden LS, Bustamante-Filho IC, Souza APB, Lopes TN, da Silva AFT, Tomé LM, Timmers LFMS, Dos Santos SI, Neves AP.The protein disulphide isomerase A1 (PDIA1) is an important chaperone involved in protein quality control and redox regulation. Also, the ability of PDIA1 to bind to oestrogens suggests that it may play a role in epididymal maturation and male fertility. The goals of this study were to (a) verify the possible interaction between 17β-estradiol and equine PDIA1 using bioinformatics; (b) identify and quantify PDIA1 protein in equine cauda epididymis throughout peripuberty; and (c) determine whether the amounts of PDIA1 in equine seminal plasma and spermatozoa are associated with fertility. Using...
Esteller-Vico A, Ball BA, Bridges JW, Hughes SE, Squires EL, Troedsson MHT.Reproductive steroids testosterone (T) and estrone sulfate (E1S) are used as diagnostic markers for cryptorchidism in horses. The human chorionic gonadotropin (hCG) stimulation test is used as a diagnostic aid because administration of this hormone results in greater incremental differences in circulating steroid concentrations. Thoughts regarding optimal sampling times following hCG administration, however, are inconsistent. Additionally, determination of half-life of these steroids is important in postsurgical samples to confirm complete removal of testicular tissue. Objectives of this study...
