Developmental programming: exposure to testosterone excess disrupts steroidal and metabolic environment in pregnant sheep

Abstract

Gestational exposure to excess T leads to intrauterine growth restriction, low birth weight, and adult metabolic/reproductive disorders in female sheep. We hypothesized that as early mediators of such disruptions, gestational T disrupts steroidal and metabolic homeostasis in both the mother and fetus by both androgenic and metabolic pathways. Maternal blood samples were measured weekly for levels of insulin, glucose, and progesterone from four groups of animals: control; gestational T (twice weekly im injections of 100 mg of T propionate from d 30 to d 90 of gestation); T plus an androgen antagonist, flutamide (15 mg/kg·d oral; T-Flutamide); and T plus the insulin sensitizer, rosiglitazone (0.11 mg/kg·d oral; T-Rosi) (n = 10-12/group). On day 90 of gestation, maternal and umbilical cord samples were collected after a 48-hour fast from a subset (n = 6/group) for the measurement of steroids, free fatty acids, amino acids, and acylcarnitines. Gestational T decreased maternal progesterone levels by 36.5% (P < .05), which was prevented by flutamide showing direct androgenic mediation. Gestational T also augmented maternal insulin levels and decreased medium chained acylcarnitines, suggesting increased mitochondrial fatty acid oxidation. These changes were prevented by rosiglitazone, suggesting alterations in maternal fuel use. Gestational T-induced increases in fetal estradiol were not prevented by either cotreatment. Gestational T disrupted associations of steroids with metabolites and progesterone with acylcarnitines, which was prevented either by androgen antagonist or insulin sensitizer cotreatment. These findings suggest a future combination of these treatments might be required to prevent alteration in maternal/fetal steroidal and metabolic milieu(s).

Figure 1.

Maternal progesterone (top), LH (middle), and FSH (bottom) plasma levels (mean ± SEM) from days 30 to 86 of gestation at weekly intervals (C, n = 12; T, n = 12, T-Flutamide, n = 10; T-Rosi, n = 10). Values with asterisk differ significantly (P < .05) from the control group. C, controls; T, treated with T; TF, treated with T plus flutamide; TR, treated with T plus rosiglitazone.

Figure 2.

Maternal (left panels) and fetal (right panels) samples. T (top; A), androstenedione (upper middle; B), estradiol (lower middle; C), and estrone (bottom; D) plasma levels (mean ± SEM) on day 90 of gestation are shown. For maternal samples, a subset of the entire group was randomly selected for steroid measures (n = 6/group). The corresponding fetal subset (range per group: n = 6–9) samples were assayed. Values with asterisks differ significantly from controls. **, P < .01; *, P < .05). C, controls; T, treated with T; TF, treated with T plus flutamide; TR, treated with T plus rosiglitazone.

Figure 3.

Maternal (left panels) and fetal (right panels) samples. Progesterone (top; A), cortisol (upper middle; B), insulin (lower middle; C), and glucose (bottom; D) plasma levels (mean ± SEM) on day 90 of gestation are shown. All maternal (range per group: n = 10–12) and fetal (range per group: n = 7–12) samples were included in these measures. Values with asterisks differ significantly from controls. *, P < .05. C, controls; T, treated with T; TF, treated with T plus flutamide; TR, treated with T plus rosiglitazone.