Experimentally induced gestational androgen excess disrupts glucoregulation in rhesus monkey dams and their female offspring

Abstract

Discrete fetal androgen excess during early gestation in rhesus monkeys (Macaca mulatta) promotes endocrine antecedents of adult polycystic ovary syndrome (PCOS)-like traits in female offspring. Because developmental changes promoting such PCOS-like metabolic dysfunction remain unclear, the present study examined time-mated, gravid rhesus monkeys with female fetuses, of which nine gravid females received 15 mg of testosterone propionate (TP) subcutaneously daily from 40 to 80 days (first to second trimesters) of gestation [term, mean (range): 165 (155-175) days], whereas an additional six such females received oil vehicle injections over the same time interval. During gestation, ultrasonography quantified fetal growth measures and was used as an adjunct for fetal blood collections. At term, all fetuses were delivered by cesarean section for postnatal studies. Blood samples were collected from dams and infants for glucose, insulin, and total free fatty acid (FFA) determinations. TP injections transiently accelerated maternal weight gain in dams, very modestly increased head diameter of prenatally androgenized (PA) fetuses, and modestly increased weight gain in infancy compared with concurrent controls. Mild to moderate glucose intolerance, with increased area-under-the-curve circulating insulin values, occurred in TP-injected dams during an intravenous glucose tolerance test in the early second trimester. Moreover, reduced circulating FFA levels occurred in PA fetuses during a third trimester intravenous glucagon-tolbutamide challenge (140 days gestation), whereas excessive insulin sensitivity and increased insulin secretion relative to insulin sensitivity occurred in PA infants during an intravenous glucose-tolbutamide test at ∼1.5 mo postnatal age. Data from these studies suggest that experimentally induced fetal androgen excess may result in transient hyperglycemic episodes in the intrauterine environment that are sufficient to induce relative increases in pancreatic function in PA infants, suggesting in this nonhuman primate model that differential programming of insulin action and secretion may precede adult metabolic dysfunction.

Fig. 1.

Diagrammatic representation of the experimental design, illustrating days of maternal subcutaneous injections [15 mg testosterone propionate (TP): n = 9; oil: n = 6] during 40–80 days gestation; days of blood sample collection in dams, fetuses, and infants; timing of cesarean section delivery; and dam, fetal, and infant tests of glucoregulation [dam: iv glucose tolerance test (ivGTT); fetus: iv tolbutamide-modified glucagon test; infant: iv tolbutamide-modified glucose test].

Fig. 2.

Mean ± SE body weight (A) and rate of weight gain (B) during pregnancy in 5 oil (○)- and 9 TP-injected (●) dams. †P < 0.03 vs. control dams at 80 days gestation. ***P < 0.001 vs. control dams at 40–80 days gestation. δP < 0.015 vs. control dams at 80–120 days gestation.

Fig. 3.

Mean ± SE body weight (A), %birth weight (B), crown-rump length (C), and femur length (D) in 5 concurrent control (◊) and 9 prenatally androgenized (PA) (■) female infants. #P < 0.04 and *P < 0.05 vs. control infants at 8 wk postnatal age.

Fig. 4.

Mean (95% confidence limits) of basal circulating glucose levels in 5 concurrent control (○) and 9 TP-exposed (●) dams between 40 and 160 days gestation (A), fetuses between 40 and 140 days gestation (B), and infants between postnatal days 1 and 45 (C). *P < 0.025 vs. 100, 120, and 140 days gestation, both female fetal groups combined. The duration of gestational treatment is indicated by the open (control) and filled (TP-treated) boxes designating the female groups. ***P < 0.001 vs. postnatal days 30 and 45, both female infant groups combined.

Fig. 5.

Mean (95% confidence limits) of basal circulating insulin levels in 5 concurrent control (○) and 9 TP-exposed (●) dams between 40 and 160 days gestation (A), fetuses between 40 and 140 days gestation (B), and infants between postnatal days 1 and 45 (C). The duration of gestational treatment is indicated by the open (control) and filled (TP-treated) boxes designating the female groups. *P < 0.018–0.01 and ***P < 0.001 vs. 40 days of gestation, both groups of dams combined.

Fig. 6.

Negative relationship between ivGTT-determined glucose clearance (K_G) in dams at 80 days of gestation and dam preconception body weight (○, oil-injected control dams; ●, TP-injected dams).

Fig. 7.

Individual values for fetal circulating levels of glucose (mg/dl) (A) and fetal circulating levels of insulin (μU/ml) (B) between 80 and 140 days of gestation and infant circulating levels of glucose (mg/dl) between postnatal days 1 and 45 (C) in 5 concurrent control (open symbols) and 9 PA (filled symbols) infants showing the PA values that exceed control ranges. The same individuals designated by the same symbol appear in all three panels, as either fetus or infant.