No abstract

These experiments establish the specificity and dose-dependent ability of PDE3, but not PDE4, inhibitors to block resumption of meiosis in macaque oocytes in vitro. Thus, PDE3 inhibitors have potential use as contraceptives in primates.

Immunocytochemical detection of androgen receptors (ARs) in several compartments of the macaque ovary, including the germinal epithelium, follicle, and corpus luteum, suggests a role for androgens in modulating ovarian function via the classical receptor-mediated pathway. To examine AR mRNA expression in the rhesus monkey ovary, total RNA was isolated from whole ovaries, the germinal epithelium-enriched cortical and medullary compartments of the ovary, and corpora lutea from early (d 3-5), mid (d 6-8), mid-late (d 10-12), and late (d 13-15) stages of the luteal phase of the menstrual cycle. RNA was also obtained from luteinized granulosa cells from monkeys receiving gonadotropin treatment to stimulate the development of multiple ovarian follicles. After reverse transcription of total RNA using oligo-dT as a primer, polymerase chain reaction (PCR) was used to amplify a unique 329 bp segment of the monkey AR hormone-binding region. Reverse transcriptase (RT)-PCR products of the expected size were detected in all ovarian and control tissues. Sequence analysis of the AR cDNA from the macaque ovary revealed 99% nucleotide homology and 100% predicted amino acid homology to the cDNA for the hormone-binding region of human AR. Northern analysis demonstrated the presence of a major AR mRNA species at 9.5 kb in corpus luteum, luteinized granulosa cells, and prostate, with additional bands detected in the corpus luteum and prostate at 7.9 and 3.4 kb, respectively. A sensitive RNase protection assay was used to examine AR mRNA levels in ovarian tissues and showed AR mRNA expression throughout the life-span of the corpus luteum. Thus, detection of AR mRNA in the primate ovary, including the periovulatory follicle and corpus luteum, supports the concept that these tissues are targets for receptor-mediated androgen action during the menstrual cycle.

The amplitude and duration of the midcycle LH surge required for periovulatory changes in the primate follicle are incompletely defined. We reported that short (4- to 14-h) LH surges were insufficient to induce periovulatory events after multiple follicular development in macaques. In contrast, an 18- to 24-h LH surge induced oocyte maturation plus granulosa cell luteinization, but did not support corpus luteum function. In this study, the periovulatory changes following LH surges of 48 h elicited using pituitary (pit) or recombinant (r) human (h) LH were compared to those after 24-h LH surge durations or after urinary hCG (u-hCG) treatment. Beginning at menses, rhesus monkeys were treated with human gonadotropins for 9 days to stimulate follicular growth. On day 10, animals (n = 3-5/group) received 1) a single injection of u-hCG [79 +/- 3 micrograms RP-1 equivalents (equiv), im], 2) two injections of pit-hLH (91 +/- 4 micrograms RP-1 equiv, im), 3) one injection of r-hLH (21 +/- 1 micrograms RP-1 equiv, im), or 4) two injections of r-hLH (21 +/- 1 micrograms RP-1 equiv). Oocytes and granulosa cells were obtained via follicle aspiration 27 h after the initial LH or hCG injection. In all groups, serum estradiol rose to similar peak levels by day 10. Circulating LH-like bioactivity was elevated for more than 48 h after u-hCG. Peak serum LH bioactivities were proportional to the administered LH doses, as determined in the in vitro bioassay. Two injections of either r-hLH or pit-hLH elicited surge levels (> 100 ng/mL) of bioactive LH for 36-48 h, whereas one injection sustained surge levels for only 18-24 h. The proportions of oocytes resuming meiosis (68-76%) were similar in all groups. Immunocytochemical staining for progesterone receptor and in vitro progesterone production by granulosa cells in all LH-treated groups were comparable to those of cells form the hCG-treated group. Peak levels of progesterone in the luteal phase were comparable in monkeys treated with two doses of pit-hLH and r-hLH (18.5 +/- 10.4 vs. 8.1 +/- 1.5 ng/mL) and approached that in u-hCG treated monkeys (39.5 +/- 18.0 ng/mL). However, progesterone levels in animals treated once with r-hLH (3.4 +/- 1.5 ng/mL) were less (P < 0.05) than those in u-hCG-treated monkeys.(ABSTRACT TRUNCATED AT 400 WORDS)