Effects of in-vivo administration of GnRH on the release of gonadotrophins in the female rabbit.
Developing female rabbits were studied weekly from Day 22 of life to Day 100. At all ages GnRH (1.5 micrograms/kg) induced a large increase in LH release 15 min later. By contrast, FSH was significantly increased only on Days 22, 29 and 72 and no significant increase was detected up to 2 h after GnRH administration at other ages. Functional corpora lutea were absent at the start of all treatments as indicated by circulating concentrations of progesterone less than 2 ng/ml. It is concluded that the immature rabbit pituitary is functionally capable of responding to GnRH with an increase in LH secretion, whereas the control of FSH secretion may be regulated by other factors.
YoungLai
E V
EV
Department of Obstetrics and Gynecology, McMaster University, Hamilton, Ontario, Canada.
Thompson
N
N
Foster
W
W
D000818:Animals; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000378:metabolism*; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D011817:Rabbits; D012741:Sexual Maturation; D013268:Stimulation, Chemical
D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone