Effects of growth hormone and gonadotrophin releasing hormone antagonists on ovarian follicle growth in sheep.
Our objective was to determine the effects of the administration of growth hormone (GH) alone or plus teverelix, a gonadotrophin releasing hormone antagonist (GnRHa), on follicle development in sheep. Ewes were treated daily for 6 days by the intramuscular route with 15 mg of GH alone (GH group; n = 6) or combined with two subcutaneous doses of GnRHa (1.5 mg) on days 0 and 3 of GH treatment (GH/GnRHa group; n = 6); the control group (n = 6) received similar treatment with saline solution. Plasma follicle stimulating hormone levels were significantly lower in the GH/GnRHa group than in the control (P < 0.001) and GH groups (P < 0.05). The number of follicles > or =2 mm increased to reach significant differences with control (18.7 +/- 0.6) on day 4 in GH/GnRHa group (22.7 +/- 0.5, P < 0.001) and on day 5 in GH group (20.3 +/- 0.4 vs. 17.0 +/- 0.6, P < 0.05). These results indicate that GH and GnRHa may be useful for increasing the number of gonadotrophin-responsive follicles in the ovary. However, follicle function could be affected as both GH and GH/GnRHa groups showed lower plasma inhibin A concentrations than control sheep (90-110 pg/mL vs. 170-185 pg/mL, P < 0.005).
Gonzalez Añover
P
P
Cátedra de Farmacología, Facultad de Veterinaria, UCM, Madrid, Spain.
Gonzalez-Bulnes
A
A
Veiga-Lopez
A
A
Garcia-Garcia
R M
RM
McNeilly
A S
AS
Encinas
T
T
D000818:Animals; D004347:Drug Interactions; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors*; D013006:Growth Hormone / Q000494:pharmacology*; D006727:Hormone Antagonists / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology*; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000254:growth & development; D012756:Sheep; D014463:Ultrasonography
D006727:Hormone Antagonists; D009842:Oligopeptides; D007987:Gonadotropin-Releasing Hormone; D013006:Growth Hormone; C084350:antarelix