Inhibition by Melatonin of Dopamine Release from Rat Hypothalamus in vitro: Variations with Sex and the Estrous Cycle

摘要: The inhibitory effect of melatonin on evoked dopamine release from whole hypothalamus as well its three regions (preoptic area, median and posterior hypothalamus) was studied in male rats female during various stages the estrous cycle. Inhibition by 1 μM significantly higher at lower diestrous than metestrous proestrous stages. variations inhibition cycle occurred predominantly preoptic were nonsignificant other hypothalamic regions. In rats, a constant level observed. addition, concentration needed to produce half maximal shifted approximately 0.6 nM more corresponding order μM, did not change.