In the agonadal, androgenized ewe testosterone before birth produces a precocious pubertal rise in circulating LH and abolishes the LH surge mechanism. The present study tested two predictions from this model in the ovary-intact female: 1) prenatal androgen exposure produces early ovarian stimulation; and 2) despite early ovarian stimulation, progestogenic cycles would not occur because of the abolition or disruption of the LH surge. Pregnant ewes were injected with testosterone propionate twice per week from either d 30-90 (T60 group; 100 mg/injection) or d 60-90 (T30 group; 80 mg/injection) of gestation (term, 147 d). Control ewes received no injections. At birth, the androgenized and control lambs were divided into two groups: ovary-intact to determine the effects of prenatal androgen on the timing of puberty and subsequent ovarian function, and ovariectomized to assess the timing of the pubertal decrease in sensitivity to estrogen negative feedback and the subsequent increase in LH. Neonatally orchidectomized, estrogen-treated males were included for comparison of the timing of this pubertal rise in LH secretion. Neuroendocrine puberty (determined on the basis of LH increase) was advanced in the androgenized females to a similar age as in males. Repeated progesterone cycles of the same duration and number occurred in the ovary-intact ewes, and they began at the same time as for control females, thus negating both predictions. Differences appeared during the second breeding season, when reproductive cycles were either absent (T60) or disrupted (T30 group). Our findings reveal that exposure to androgens in utero causes a progressive loss of cyclic function in adulthood.
We studied the impact of prenatal androgen exposure on the timing of onset of puberty, maintenance of cyclicity in the first breeding season, and the LH surge mechanism in female sheep. Pregnant sheep were injected with testosterone propionate (100 mg i.m.) twice each week from Day 30 to Day 90 (D30-90) or from Day 60 to Day 90 (D60-90) of gestation (term = 147 days). Concentrations of plasma progesterone and gonadotropins were measured in blood samples collected twice each week from control (n = 10), D60-90 (n = 13), and D30-90 (n = 3) animals. Rate of weight gain and initiation of estrous behavior were also monitored. After the first breeding season, when the animals entered anestrus, competency of the gonadotropin surge system to respond to estradiol positive feedback was tested in the absence or presence of progesterone priming for 12 days. Prenatally androgenized females had similar body weight gain and achieved puberty (start of first progestogenic cycle) at the same time as controls. Duration of the breeding season and the number of cycles that occurred during the first breeding season were similar between control and prenatally androgenized sheep. In contrast, prenatal exposure to androgens compromised the positive feedback effects of estradiol. Onset of LH/FSH surges following the estradiol stimulus was delayed in both groups of androgenized ewes compared with the controls in both the absence and presence of progesterone priming. In addition, the magnitude of LH and FSH surges in the two animals that surged in the D30-90 group were only one third and one half, respectively, of the magnitudes observed in the control and D60-90 groups. The present findings indicate that disruption of the surge system can account for the fertility problems that occur during adulthood in prenatally androgenized sheep.
Exposure of the female sheep fetus to exogenous testosterone in early pregnancy permanently masculinizes the reproductive neuroendocrine axis. Specifically, in utero androgens given to female lambs from day 30 to 90 of a 147 day pregnancy dramatically altered the response of the gonadotropin releasing hormone (GnRH) neuronal network in the hypothalamus to both estrogen (E) and progesterone (P) feedback. Elevated concentrations of estrogen stimulated a massive release of GnRH in gonadectomized female sheep; however, male and androgenized female lambs were unable to respond to high E concentrations by producing this preovulatory-like "surge" of GnRH. Further, the inhibitory actions of progesterone (P) were also sexually differentiated and adult males and androgenized females were much less responsive to P-negative feedback than normal ewes. The consequences of these abnormal steroid feedback mechanisms were reflected in the fact that only 72% of ovary-intact androgenized ewes exhibited normal estrous cycles in their first breeding season whereas none had a single estrous cycle during the second breeding season. In contrast, 100% of the control animals exhibited repeated reproductive cycles in both seasons. These data indicate that a relatively short exposure to male hormones during in utero life permanently alters the neural mechanisms that control reproduction and leads progressively to a state of infertility.
Studies investigating autistic community research priorities indicate a mismatch between what autism research focuses on and what autistic people want to see researched. Further, there has not been a research priority-setting exercise specifically with autistic people in Scotland, where there are unique cultural, political, and social contexts. Using a community-based participatory design, we aimed to identify the research priorities of autistic adults living in Scotland. Autistic and non-autistic researchers designed and conducted a survey where 225 autistic adults rated and ranked research topics in order of importance and provided qualitative feedback on issues and questions important to them. The top five research priorities were: mental health/wellbeing, identification and diagnosis of autistic people, support services, knowledge and attitudes towards autistic people, and issues impacting autistic women. There were differences in priorities according to different intersections of identity, and qualitative responses indicated a desire for research to focus on support and understanding. The bottom three priorities concerned genetics, treatments and interventions, and causes. These findings emphasise the need to address the gap between what autism research focuses on and the everyday lives of autistic people.
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