Exposure of female sheep fetuses to excess testosterone (T) during early to midgestation produces postnatal hypergonadotropism manifest as a selective increase in LH. This hypergonadotropism may result from reduced sensitivity to estradiol (E 2 ) negative feedback and/or increased pituitary sensitivity to GnRH. We tested the hypothesis that excess T before birth reduces responsiveness of LH and FSH to E 2 negative feedback after birth. Pregnant ewes were treated with T propionate (100 mg/kg in cotton seed oil) or vehicle twice weekly from d 30 -90 gestation. Responsiveness to E 2 negative feedback was assessed at 12 and 24 wk of age in the ovaryintact female offspring. Our experimental strategy was first to arrest follicular growth and reduce endogenous E 2 by administering the GnRH antagonist (GnRH-A), Nal-Glu (50 g/kg sc every 12 h for 72 h), and then provide a fixed amount of exogenous E 2 via an implant. Blood samples were obtained every 20 min at 12 wk and every 10 min at 24 wk before treatment, during and after GnRH-A treatment both before and after E 2 implant. GnRH-A ablated LH pulsatility, reduced FSH by approximately 25%, and E 2 production diminished to near detection limit of assay at both ages in both groups. Prenatal T treatment produced a precocious and selective reduction in responsiveness of LH but not FSH to E 2 negative feedback, which was manifest mainly at the level of LH/GnRH pulse frequency. Collectively, these findings support the hypothesis that prenatal exposure to excess T decreases postnatal responsiveness to E 2 inhibitory feedback of LH/GnRH secretion to contribute to the development of hypergonadotropism. (Endocrinology 146: 4281-4291, 2005)

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Seasonal variations in the concentrations of groundwater with respect to arsenic, lead, cadmium and aluminium has been studied in Dhemaji district of Assam, India. The water samples were collected from 20 different sites in both dry and wet seasons. The metals were analysed by using atomic absorption spectrometer, Perkin Elmer AAnalyst 200 model. The concentrations of aluminium, lead and cadmium in groundwater were found to be significantly elevated. High concentrations of all the metals were recorded in the dry season than in the wet season. Univariate statistics along with skewness, kurtosis and confidence limit have been calculated for both the seasons to test the distribution normality for each metal. Statistical analyses of the data reveal non-uniform distribution of the metals in the area. The metal contamination of groundwater in the district follows the trend Al>Pb>Cd>As in both the seasons.