Endocrine antecedents of polycystic ovary syndrome in fetal and infant prenatally androgenized female rhesus monkeys

Abstract

Experimentally induced fetal androgen excess induces polycystic ovary syndrome-like traits in adult female rhesus monkeys (Macaca mulatta). Developmental changes leading to this endocrinopathy are not known. We therefore studied 15 time-mated, gravid female rhesus monkeys with known female fetuses. Nine dams received daily s.c. injections of 15 mg of testosterone propionate (TP), and six received injections of oil vehicle (control) from 40 through 80 days of gestation (term, 165 days; range, +/-10 days). All fetuses were delivered by cesarean section using established methods at term. Ultrasound-guided fetal blood sample collection and peripheral venous sample collection of dams and subsequent infants enabled determination of circulating levels of steroid hormones, LH and FSH. The TP injections elevated serum testosterone and androstenedione levels in the dams and prenatally androgenized (PA) fetuses. After cessation of TP injections, testosterone levels returned to values within the reference range for animals in these age groups, whereas serum androstenedione levels in PA infants were elevated. The TP injections did not increase estrogen levels in the dams or the PA fetuses or infants, yet conjugated estrogen levels were elevated in the TP-injected dams. Serum levels of LH and FSH were elevated in late-gestation PA fetuses, and LH levels were elevated in PA infants. These studies suggest that experimentally induced fetal androgen excess increases gonadotropin secretion in PA female fetuses and infants and elevates endogenous androgen levels in PA infants. Thus, in this nonhuman primate model, differential programming of the fetal hypothalamo-pituitary unit with concomitant hyperandrogenism provides evidence to suggest developmental origins of LH and androgen excess in adulthood.

Figure 1

Diagrammatic representation of the experimental design, illustrating days of maternal subcutaneous injections (15 mg TP: n=9; oil: n=6) during 40-80 days of gestation, days of blood sample collection in dams, fetuses and infants, timing of caesarean-section delivery, and fetal and infant GnRH tests.

Figure 2

Serum testosterone levels (backtransformed means [95% confidence limits]) in (a) gravid female rhesus monkeys receiving 15 mg TP (filled circles, dashed line) or oil (open circles, solid line) injections during 40-80 days of gestation, and their fetuses (b) and infants (c). * p <0.001, # p<0.006 vs controls on the same day of gestation.

Figure 3

Serum androstenedione levels (backtransformed means [95% confidence limits]) in (a) gravid female rhesus monkeys receiving 15 mg TP (filled circles, dashed line) or oil (open circles, solid line) injections during 40-80 days of gestation, and their fetuses (b) and infants (c). * p<0.001 vs controls on the same day of gestation, # p<0.03 vs controls on postnatal days 1 and 30 combined.

Figure 4

Serum estradiol levels (backtransformed means [95% confidence limits]) in (a) gravid female rhesus monkeys receiving 15 mg TP (filled circles, dashed line) or oil (open circles, solid line) injections during 40-80 days of gestation, and their fetuses (b) and infants (c).

Figure 5

Serum estrone levels (backtransformed means [95% confidence limits]) in (a) gravid female rhesus monkeys receiving 15 mg TP (filled circles, dashed line) or oil (open circles, solid line) injections during 40-80 days of gestation, and their fetuses (b) and infants (c). * p<0.03, † p<0.05 vs controls on the same day of gestation.

Figure 6

Serum bioLH levels (backtransformed means and individual values) in prenatally androgenized (filled bars and symbols) and control (open bars and symbols) female (a) fetuses on the last day of TP or oil subcutaneous injections, and 20 and 40 days later, and (b) newborn and 30-day old infants. * p<0.001, # p<0.025 vs controls on the same day of gestation, † p<0.015 vs controls on postnatal days 1 and 30 combined.

Figure 7

Serum gonadotropin levels following an intravenous injection of exogenous GnRH in prenatally androgenized (PA; filled circles) and control (open circles) female monkeys: fetal responses to 5μg GnRH at 120 days of gestation (a) bioLH and (b) FSH, and infant responses to 20μg GnRH at (c) 30 days postpartum (bioLH; ∼0700h), and (d) 37 days postpartum (bioLH; ∼2100h). * p<0.05 vs controls, all times combined, † p<0.05, vs. 0 min, all females combined, †† p<0.002, vs. 0 min, all females combined, §§ p<0.015, vs 10 min, PA females only, § p<0.03, vs 20 min, PA females only.