Passive immunization of cyclic mares against androgen: gonadotropin and progesterone concentrations and estrous characteristics.
Abstract: Antiserum generated in a horse against testosterone conjugated to bovine serum albumin (BSA) was administered to six lighthorse mares (androgen-immunized mares) 1 to 3 d before a prostaglandin-induced estrus and twice again at 2-d intervals. Six control mares were administered antiserum generated against BSA on the same schedule. Relative to testosterone, cross-reactivities of other steroids with the testosterone antiserum were (%): dihydrotestosterone, 52; 5 alpha-androstane-3 alpha,17 beta-diol, 8.6; androst-4-ene-3,17-dione, 1.2; and all others tested less than .1. Tritiated testosterone binding in plasma increased (P less than .01) in androgen-immunized mares within 1 h and remained elevated (P less than .01) relative to controls for greater than 21 d. There was no effect (P greater than .10) of passive immunization against androgen on interval to estrus after prostaglandin injection, duration of estrus, ovarian volume, number of palpable follicles or follicular volume during estrus. In contrast, concentrations of luteinizing hormone (LH) were higher (P less than .05) in androgen-immunized mares than in control mares during estrus and early diestrus. Concentrations of follicle stimulating hormone (FSH) and progesterone at those times were not affected (P greater than .10). From these data, we conclude that androgens in the mare during estrus may be involved with the regulation of LH secretion. In contrast, no involvement with FSH secretion was apparent under these short-term conditions.
Publication Date: 1987-03-01 PubMed ID: 3106293DOI: 10.2527/jas1987.643797xGoogle Scholar: Lookup
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- Journal Article
Summary
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The research examines the effect of an androgen immunization on the hormonal and estrous behavior of female horses. It suggests that while androgens may regulate luteinizing hormone (LH) secretion during estrus, they do not appear to affect follicle stimulating hormone (FSH) secretion in short-term scenarios.
Immunization Process
- The study was conducted on six lighthorse mares that were immunized against androgens. The immunization was done using antiserum generated in a horse against testosterone linked to bovine serum albumin (BSA).
- The control group in this study involved six mares which were administered antiserum produced against BSA without any testosterone linkage.
- This immunization was delivered one to three days prior to a prostaglandin-induced estrus, and two more doses were given at two-day intervals.
Evaluation of Immunization Effects
- The researchers tested the cross-reactivities of several steroids with the testosterone antiserum. Dihydrotestosterone had a 52% cross-reactivity, and all other tested steroids had less than 0.1% cross-reactivity.
- Observations revealed that within one hour of immunization, tritiated testosterone (a form of testosterone bound with tritium for tracking) binding in the plasma of immunized mares increased significantly and remained elevated for over 21 days.
Impact on Estrous Behavior and Hormone Secretion
- The study found that passive immunization against androgen had no significant effect on the time to estrus post prostaglandin injection, the duration of estrus, ovarian volume, or the number of palpable follicles/follicular volume during estrus.
- However, levels of luteinizing hormone (LH) were significantly higher in androgen-immunized mares compared to the control group during estrus and early diestrus.
- No significant changes were recorded in the concentrations of follicle-stimulating hormone (FSH) and progesterone at these times.
Conclusion
- The findings suggest that androgens in female horses (mares) during estrus may play a role in the regulation of luteinizing hormone (LH) secretion.
- In contrast, no apparent involvement was found with follicle-stimulating hormone (FSH) secretion under these short-term conditions.
Cite This Article
APA
Thompson DL, Wiest JJ, Garza WF, Ashley KB, McNeill DR.
(1987).
Passive immunization of cyclic mares against androgen: gonadotropin and progesterone concentrations and estrous characteristics.
J Anim Sci, 64(3), 797-804.
https://doi.org/10.2527/jas1987.643797x Publication
Researcher Affiliations
MeSH Terms
- Androgens / immunology
- Animals
- Dinoprost
- Estrus / drug effects
- Female
- Follicle Stimulating Hormone / blood
- Horses / immunology
- Immunization, Passive
- Luteinizing Hormone / blood
- Progesterone / blood
- Prostaglandins F / pharmacology
Citations
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