Effect of suppression of plasma prolactin on ovulation, plasma gonadotrophins and corpus luteum function in LH-RH-treated anoestrous ewes.
Nineteen Scottish Blackface ewes were given LH-RH (3 X 30 micrograms i.v., 90-min intervals) during anoestrus when prolactin levels were elevated. Plasma levels of prolactin were suppressed with CB 154 (twice daily, i.m.) on Days -5 to 0 (N = 5), 0 to +5 (N = 5) or -5 to +5 (N = 5) around the day of LH-RH treatment (Day 0). Control animals (N = 4) received saline on Days -5 to +5. Nine animals ovulated forming corpora lutea as judged by laparoscopy on Day +7. No difference in FSH or LH levels was found between treatments and ovulations occurred equally in all treatment groups. Progesterone levels were less than ng/ml in all animals up to Day 14. It is concluded that short-term suppression of prolactin does not affect the incidence of ovulation or corpus luteum progesterone production in LH-RH-treated anoestrous ewes.
D000780:Anestrus; D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology; D003338:Corpus Luteum / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000097:blood*; D010060:Ovulation / Q000187:drug effects; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood*; D012756:Sheep
D007987:Gonadotropin-Releasing Hormone; D001971:Bromocriptine; D011374:Progesterone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone