Abstract
To evaluate the role of prolactin (PRL) in nonshivering thermogenesis (NST), the effects of hyper- and hypo-prolactinemia on in vitro brown adipose tissue (BAT) thermogenesis were investigated. In male rats cold-exposure for 1 hr or 1 day decreased plasma PRL levels, but after cold-acclimation the levels returned to the warm-acclimated control values. Saline injection elevated the plasma PRL level and this elevation was blocked by noradrenaline (NA) . In female animals haloperidol-treatment suppressed, while bromocriptine-treatment enhanced the in vitro responsiveness of BAT to glucagon (G), but not to NA. Dopamine mimicked the responses of BAT to bromocriptine. PRL may inhibit nonshivering thermogenesis, especially by modifying the thermogenic action of G in BAT.
