Effects of in vivo administration of testosterone propionate on in vitro production of follicle-stimulating hormone and luteinizing hormone by pituitaries of pony mares.

The in vitro incorporation of [3H]leucine into immunoprecipitable follicle-stimulating hormone (FSH) and luteinizing hormone (LH) was assessed for pituitaries from pony mares treated with testosterone propionate (TP) or oil (controls). Mares were treated every other day with TP (n = 4) at 350 micrograms/kg of body weight or with an equivalent volume of oil (n = 4). One day following the sixth injection of TP, each mare received an intravenous injection of gonadotropin releasing hormone (GnRH) at 1.0 micrograms/kg body weight and was bled frequently for 4 h. Treatment of mares with TP reduced FSH (P less than 0.05) and LH (P less than 0.01) concentrations in daily blood samples and increased (P less than 0.01) the amount of FSH secreted in response to GnRH compared with control mares. Incorporation of [3H]leucine into immunoprecipitable FSH was also greater (P less than 0.01) in pituitaries from TP-treated mares compared with control mares on both a per mg tissue and per anterior pituitary basis. The amount of LH secreted after GnRH, the amount left in the pituitary and the incorporation of [3H]leucine into LH were not affected by treatment. These results confirm earlier conclusions drawn from indirect evidence that androgens increase the production of FSH in the mare.

[1]  D. Thompson,et al.  Testosterone effects on gonadotropin response to GNRH: cows and pony mares. , 1984, Journal of animal science.

[2]  D. Thompson,et al.  Effects of testosterone, dihydrotestosterone and estradiol on gonadotropin release after gonadotropin releasing hormone administration in cyclic mares. , 1983, Biology of reproduction.

[3]  D. Thompson,et al.  Testosterone administration to mares during estrus: duration of estrus and diestrus and concentrations of LH and FSH in plasma. , 1983, Journal of animal science.

[4]  D. Thompson,et al.  Testosterone effects on mares during synchronization with altrenogest: FSH, LH, estrous duration and pregnancy rate. , 1983, Journal of animal science.

[5]  D. Thompson,et al.  Effect of testosterone and estradiol-17 beta alone and in combination on LH and FSH concentrations in blood serum and pituitary of geldings and in serum after administration of GnRH. , 1979, Biology of reproduction.

[6]  E. Steinberger,et al.  The effects of testosterone propionate and estradiol benzoate on the vitro synthesis of FSH. , 1977, Biology of reproduction.

[7]  D. Thompson,et al.  Reproductive physiology of the stallion. VIII. Artificial photoperiod, collection interval and seminal characteristics, sexual behavior and concentrations of LH and testosterone in serum. , 1977, Journal of Animal Science.

[8]  E. Steinberger,et al.  Biosynthesis of gonadotrophins by rat pituitaries in vitro. , 1975, The Journal of endocrinology.

[9]  E. M. Bogdanove,et al.  Qualitative and quantitative gonad-pituitary feedback. , 1975, Recent progress in hormone research.

[10]  V. Gay,et al.  Follicle-stimulating hormone secretion in the female rat: cyclic release is dependent on circulating androgen. , 1975, Science.

[11]  T. Louis,et al.  Luteinizing Hormone Release by Gonadotropin Releasing Hormone Before and After Castration in Bulls 1 , 1974, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[12]  B. W. Pickett,et al.  REPRODUCTIVE PHYSIOLOGY OF THE STALLION , 1974 .

[13]  V. Gay,et al.  Follicle-Stimulating Hormone Secretion in the Female Rat: Cyclic Release Is Dependent on Circulating Androgen , 1974, Science.

[14]  H. Hafs,et al.  Analysis of repeated measurements of animals. , 1971, Journal of animal science.

[15]  H. M. Radford,et al.  The effect of testosterone propionate on ovarian activity in sheep. , 1971, Journal of reproduction and fertility.

[16]  E. M. Bogdanove,et al.  Plasma and pituitary LH and FSH in the castrated rat following short-term steroid treatment. , 1969, Endocrinology.

[17]  E. M. Bogdanove,et al.  Changes in pituitary and plasma levels of LH and FSH after cessation of chronic androgen treatment. , 1967, Endocrinology.

[18]  F. N. David,et al.  Principles and procedures of statistics. , 1961 .

[19]  O. H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.