Plasma dopamine-β-hydroxylase activity and norepinephrine levels during the human menstrual cycle

Plasma samples obtained throughout the normal menstrual cycles of six women were analyzed for dopamine-β-hydroxylase activity (DBH), norepinephrine (NE), follicle-stimulating hormone, luteinizing hormone, and prolactin. Neither DBH activity nor NE concentrations paralleled changes in plasma gonadotropins and prolactin. No consistent pattern of either plasma DBH activity or NE concentrations during the normal menstrual cycle was noted. Thus, an association between peripheral sympathetic nervous system activity and the midcycle surge in plasma gonadotropins reported by others was not reproducible in our study of normally menstruating women.