title: Increased ovulation rate in the cyclic guinea-pig after a single injection of an antiserum to LH.
abstract: Cyclic guinea-pigs were injected s.c. on Day 12 (Day 1 = day of ovulation) of the cycle with 0.4 or 0.8 ml equine antiserum to bovine LH or with 0.4 ml normal horse serum (NHS). Treatment with 0.4 or 0.8 ml anti-LH delayed vaginal opening by 3 days and prolonged the oestrous cycle to 20 days compared with 16 days in controls; ovulation rates for these treatments were 5.6 +/- 0.6 ova (P < 0.01), 4.5 +/- 0.9 ova and 2.9 +/- 0.3 ova respectively. Serum concentrations of oestradiol and progesterone were not affected but androgen values were decreased by treatment with LH antiserum. The number of antral follicles (< 520 micron diam./ovary) 48 h after 0.4 ml anti-LH (Day 14) was similar to that observed in controls, but on Day 18 6.0 +/- 1.4 follicles/ovary were present in antiserum-treated guinea-pigs, whereas in controls on Day 16 there were only 2.4 +/- 0.5 antral follicles. The results indicate that the increased ovulation rate induced in the guinea-pig by LH antiserum is not associated with recruitment of increased numbers of antral follicles but may be related to reduced atresia at the end of the cycle.
mesh_terms: D000728:Androgens / Q000097:blood; D000818:Animals; D004958:Estradiol / Q000097:blood; D004971:Estrus; D005260:Female; D006168:Guinea Pigs; D007986:Luteinizing Hormone / Q000502:physiology*; D006080:Ovarian Follicle / Q000254:growth & development; D010060:Ovulation; D011247:Pregnancy; D011374:Progesterone / Q000097:blood
chemical_list: D000728:Androgens; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone