Twenty-three rhesus monkeys were subjected to 9 days of ovarian hyperstimulation with sequential exposure to human follicle-stimulating hormone (hFSH) and then human luteinizing hormone (hLH) + hFSH. Six animals (26%) did not exhibit sustained, elevated levels of circulating estradiol, primarily due to the occurrence of a premature surge of endogenous LH (n = 4). Seventeen animals (74%) responded with supraphysiologic levels of circulating estradiol (peak value: means = 4480 pg/ml) and received human chorionic gonadotropin (hCG) on Day 10. Oocytes were collected 26 h later by aspiration of large antral follicles. Oocyte quantity (means = 18/animal) and quality (63% mature) were evaluated by in vitro fertilization (IVF), embryonic development, and embryo transfer to foster mothers. Modified conditions for the successful fertilization of oocytes used a Tyrode's augmented (TALP) medium supplemented with 0.3% bovine serum albumin (BSA). Oocytes were inseminated at the metaphase II stage with ejaculated, washed sperm (50 100 x 10(3)/ml) preexposed at ambient temperature to caffeine and dibutyryl cyclic adenosine 3'5'-monophosphate. Successful fertilization ranged from 26% to 75%. In one experiment, 5 of 11 embryos produced by IVF developed in vitro to hatched blastocysts. Embryo freezing employed a propanediol-based protocol and was applied to early cleavage-stage embryos with 100% (5 of 5) post-thaw survival. Two frozen-thawed embryos were transferred transtubally on 3 occasions into rhesus monkeys during the early luteal phase of spontaneous menstrual cycles. One pregnancy resulted, which proceeded normally to the unassisted delivery of a male offspring 170 days after the LH surge. We conclude that this sequential regimen of human gonadotropins provides a cohort of oocytes from rhesus monkeys that will complete meiotic maturation and fertilize in vitro, with embryonic development proceeding in vitro and in vivo. The production of putative antibodies to human gonadotropins, assessed by the presence of Protein A-precipitated hCG binding components in sera, limits the repeated use of monkeys in the hyperstimulation protocol. Nevertheless, this model system should facilitate further studies on oocyte maturation, fertilization, and early embryogenesis in primates.

This study was designed to identify suitable treatment regimens of human gonadotropin for superovulation of rhesus monkeys. At menses, female monkeys were given one of three regimens: Plan A [days 1 to 6, 60 IU human follicle-stimulating hormone (hFSH); days 7 to 9, 60 IU hFSH/60 IU human luteinizing hormone (hLH)], Plan B [days 1 to 3, 75 IU FSH/20 IU LH; days 4 to 6, 60 IU FSH/20 IU LH; days 7 to 9, 45 IU FSH/45 IU LH], or Plan C [days 1 to 9, 60 IU FSH/60 IU LH]. On day 10, human chorionic gonadotropin (hCG; 1000 IU) was administered. Serum estrogen levels peaked on the day of hCG treatment (day 10) in Plans A and C but earlier (day 8) in Plan B. An oviduct lavage recovered 1 to 3 oocytes in Plan B but 3 to 13 oocytes in the other treatment groups. Peak progesterone levels in the luteal phase were greater (P less than 0.05) in animals receiving Plan A or C than Plan B. Regardless of treatment group, progesterone levels declined abruptly 7 days after ovulation induction; the length of the luteal phase in all groups was significantly less than that of normal menstrual cycles. We conclude that regimens of hFSH and hLH (i.e., Plans A and C), followed by hCG, reliably superovulate rhesus monkeys. However, the premature decline in luteal function around the typical time of implantation may compromise pregnancy initiation and maintenance.

To determine whether dideoxyinosine is actively transported across the placenta, four pregnant macaques (Macaca nemestrina) near term and their fetuses were infused intravenously in random order with simultaneous doses of dideoxyinosine (42.5 ,ug/min/kg of body weight) and antipyrine (41.7 ,ug/min/kg) for 30 h. The infusions took place after the dams had been chronically catheterized at 128 ± 0.8 days of gestation. In a third infusion, the dams alone received a higher dosage of dideoxyinosine (425 ,ug/min/kg) and the same dosage of antipyrine (41.7 ,ug/min/kg). Samples of maternal and fetal blood and amniotic fluid were collected at intervals for up to 30 h. The concentrations of dideoxyinosine and antipyrine were determined by high-performance liquid chromatography. The transplacental maternal-fetal drug clearances were compared by the paired Student's t test. The ratio (mean ± standard deviation) of the steady-state plasma dideoxyinosine concentration in the fetus to that in the dam was 0.49 ± 0.10 at the low dideoxyinosine infusion rate and 0.51 ± 0.00 at the high dideoxyinosine infusion rate. The clearance associated with maternal-fetal transfer of the drug, CLdf (0.38 ± 0.21 ml/min/kg), was not significantly different (P > 0.05) from the clearance associated with fetal-maternal transfer of the drug, CLfd (0.56 ± 0.27 ml/min/kg). Also, CLdf was not significantly different (P > 0.05) from CLfd when normalized with respect to the corresponding transplacental clearance of antipyrine (0.07 ± 0.04 CLdf versus 0.09 ± 0.04 CLfd). Our data indicate that passage of dideoxyinosine across the placenta in pregnant M. nemestrina near term is passive and constant over the dosage range studied.Dideoxyinosine (2',3'-dideoxyinosine; didanosine) is the second dideoxynucleoside to be approved for use in the treatment of AIDS. Although not presently approved for use during pregnancy, dideoxyinosine may be of benefit to pregnant women who cannot tolerate or have become resistant to zidovudine. In addition, data from animal models indicate that dideoxynucleoside therapy of the dam during pregnancy may delay the onset and progression of the disease in offspring infected in utero (15). Thus, information on the extent and mechanisms of transplacental transfer of dideoxynucleosides, including dideoxyinosine, is necessary in the development of therapeutic strategies for the pregnant woman and her potentially infected unborn child. As part of an ongoing series of studies on the dideoxynucleosides, we studied the extent and mechanisms of transfer of dideoxyinosine in vivo across the placenta in a representative nonhuman primate model, Macaca nemestrina.The macaque was chosen because of its anatomical and physiological similarities to humans. It is particularly suitable since it is susceptible to both the simian immunodeficiency virus (12), which produces an AIDS-like syndrome, and the human immunodeficiency virus (1). In addition, the pharmacokinetics of dideoxyinosine in M. nemestrina have been shown to be similar to those in humans (1...

The physiological significance of locally produced prostaglandins (PGs) in the regulation of the functional lifespan of the primate corpus luteum is unknown. In the current study, the PG synthesis inhibitor sodium meclofenamate was administered to adult female rhesus monkeys beginning in the midluteal phase of the menstrual cycle. Meclofenamate was infused continuously for 7 days into the corpus luteum (100 micrograms/h, n = 6) or the jugular vein (100 micrograms/h, n = 3; 1000 micrograms/h, n = 3) via osmotic minipump. As controls, PBS was infused into the corpus luteum (n = 7) or jugular vein (n = 5). In some of the monkeys receiving intraluteal infusions, chronic aortic and utero-ovarian venous catheters were implanted, and blood samples were collected on alternate days for the measurement of PGE and PGF2 alpha by RIA. Saphenous venous blood was collected daily, and progesterone and cortisol levels were determined by RIA. LH levels were determined by the mouse Leydig cell bioassay. Progesterone levels over 5 days preceding treatment were not different among groups. A decline in progesterone levels on day 1 after surgery was observed in all treatment groups and was accompanied by a 1-day elevation in cortisol levels. Thereafter, five of seven monkeys who received intraluteal infusions of PBS displayed normal progesterone patterns during treatment and normal luteal phase lengths of 15.4 +/- 1.2 days (mean +/- SEM). In six monkeys that received intraluteal infusions of meclofenamate, progesterone levels typically fell to less than 1 ng/ml within 72 h after initiation of infusion; progesterone levels during 7 days of intraluteal infusion were significantly lower (P less than 0.01) in meclofenamate- vs. PBS-treated monkeys. Meclofenamate infusion into the corpus luteum significantly shortened (P less than 0.01) the luteal phase to 10.5 +/- 1.0 days. In contrast, progesterone levels during 7 days of meclofenamate infusion into the jugular vein did not differ from those in PBS-treated monkeys, and the length of the luteal phase was unaltered. LH levels, measured daily, did not differ among groups either before or during treatment. Although an venous/arterial gradient in PGE was detected at the time of surgery, we were unable to detect a significant gradient across the ovary in PGE or PGF2 alpha at any time after surgery in monkeys treated with either PBS or meclofenamate. The present data suggest an obligatory luteotropic role for locally produced metabolites of arachidonic acid, but a physiological role for either PGE or PGF2 alpha in regulating the primate corpus luteum remains equivocal.

No abstract