Effect of LHRH immunoneutralization on follicular development, the LH surge and luteal function in the stumptailed macaque monkey (Macaca arctoides)

Abstract

A dose of 100 \ g=m\ l of a potent ovine LHRH gamma globulin inhibited ovulation in the cyclic rat when administered at 12:00 h on the day of pro-oestrus. A dose of 10 ml of the preparation was administered i.v. to female stumptailed macaques to achieve circulating antibody titres 3\p=n-\4-fold higher than in the rat. In an ovariectomized macaque, this caused a marked fall in serum concentrations of LH to less than 10% of pretreatment values and also a significant, though less pronounced, fall in FSH. Six monkeys were treated with the LHRH gamma globulin during the mid\p=n-\latefollicular phase of the cycle. In 2 monkeys in which serum oestradiol concentrations were <100 pg/ml at the time of antibody administration, the rising oestradiol levels were abruptly suppressed and the normal mid-cycle LH surge failed to occur. Serum concentrations of LH and FSH declined to low levels for 8\p=n-\10 days after which time normal follicular development occurred. In the remaining 4 monkeys in which follicular development was more advanced as indicated by serum oestradiol concentrations of >100 pg/ml, the antibodies induced either a transient decline or had no effect on the rising serum concentration of oestradiol. An LH/FSH surge followed by a rise in serum progesterone occurred in these macaques. When the antibodies were administered to a further 6 macaques, which had also been treated with oestradiol benzoate during the early follicular phase to induce an LH surge, the neutralization of LHRH again failed to block the surge even when the dose of antibody was increased to 20 ml. The results show that LHRH antibodies were unable to block the LH surge in the macaque. They contrast with results obtained with LHRH immunoneutralization in the sheep, rat, hamster, mouse and bird and suggest that the ability of oestrogen to induce an LH surge by acting directly on the LHRH-primed anterior pituitary gland is more dominant in the primate.

Follicle-Stimulating Hormone-Inhibin B Interactions during the Follicular Phase of the Primate Menstrual Cycle Revealed by Gonadotropin-Releasing Hormone Antagonist and Antiestrogen Treatment

“…The assays used 50 L serum in duplicate and had sensitivities of 4 ng/L for inhibin A and 16 ng/L for inhibin B. Estradiol-17␤ and progesterone were measured by RIAs (13), detection limits being 30 pmol/L and 0.7 nmol/L, respectively. Macaque FSH was measured as described (14) using a heterologous RIA with a detection limit of 2 g/L NICHHD cyn-FSH-RP1, and inter-and intraassay coefficients of variance of 15 and 11%, respectively. LH was measured by RIA, based upon recombinant cynomolgus monkey LH and supplied by the National Hormone and Pituitary Program, NIDDKD.…”

Immunoneutralization and immunocytochemical localization of inhibin α subunit during the mid-luteal phase in the stump-tailed macaque

“…Hormone assays and analysis of data Serum concentrations of FSH were measured by a heterologous radioimmunoassay as described pre¬ viously (Fraser, McNeilly, Abbott & Steiner, 1986), using antibody M94, raised in a rabbit against human FSH. Ovine FSH-I-l-NIH was used as tracer and results are expressed in terms of NICHHD cyn-FSH-RPI (supplied by Dr S. Raiti, National Hormone and Pituitary Program, Baltimore, MD, U.S.A.).…”

“…The detection limit of the assay was 2 pg/1 and inter-and intra-assay coefficients of variance were 15 and 11 % respectively. In addition, selected samples were assayed using antibody NIAMDKD hFSH-4 (Dr S. Raiti) in an assay also described by Fraser et al (1986) which utilized a human FSH tracer (supplied by Dr . Ferguson, Chelsea Hospital for Women, London, U.K.) and had a detection limit of 5 pg NICHHD cyn-FSH-RPI/1.…”

Effects of an LH-releasing hormone antagonist on the secretion of LH, FSH, prolactin and ovarian steroids at different stages of the luteal phase in the stumptailed macaque (Macaca arctoides)

“…Luteinizing hormone and FSH were measured by radioimmunoassay (RIA) as described previously (Fraser, Laird & Blakeley, 1980;Fraser, McNeilly, Abbott & Steiner, 1986). Intra-and interassay coef¬ ficients of variation were less than 12% in each RIA.…”