Sex differences in estradiol stimulated progesterone synthesis in adult hypothalamic astrocytes. Estradiol at 1 and 100 nmol/l stimulated significant progesterone synthesis in female wild type astrocytes (P < 0.05 versus control). Conversely, male wild type astrocytes were not stimulated by estradiol (1 or 100 nmol/l) to synthesize progesterone (P > 0.05 versus controls). *Significantly different compared with female control and all male groups (P < 0.05, one-way ANOVA with Student-Newman-Keuls post hoc test). †Significantly different compared with female astrocytes stimulated with 1 nmol/l estradiol (P < 0.05, one-way ANOVA with Student-Newman-Keuls post hoc test).