Chan E, Swaminathan R
Department of Chemical Pathology, Chinese University of Hong Kong, Shatin, New Territories.
Am J Physiol. 1990 Jan;258(1 Pt 2):R51-6. doi: 10.1152/ajpregu.1990.258.1.R51.
During lactation the efficiency of energy utilization is increased and brown adipose tissue (BAT) thermogenesis is suppressed. We have examined the role of prolactin in the suppression of BAT during lactation in the rat. Changes in BAT were studied using an enzyme-linked immunosorbent assay for the uncoupling protein (UCP). In the first experiment BAT from pregnant and lactating rats was examined at various times. Total UPC content of BAT decreased from 364 +/- 34 to 32 +/- 9 micrograms during late lactation (20 days). Serum prolactin (PRL) concentration was elevated during lactation and was highest at 10 days. When endogenous PRL was stimulated by injection of metoclopramide (1.67 mg/kg) for 5 days, UCP content of BAT decreased by 50%. This action of metoclopramide could be blocked by simultaneous administration of bromocriptine, an inhibitor of PRL secretion. Serum PRL concentration was elevated during metoclopramide administration but not when metoclopramide and bromocriptine were given together. We conclude that PRL is a possible mediator of the suppression of BAT during lactation.
在哺乳期，能量利用效率提高，棕色脂肪组织（BAT）的产热受到抑制。我们研究了催乳素在大鼠哺乳期抑制BAT中的作用。使用针对解偶联蛋白（UCP）的酶联免疫吸附测定法研究了BAT的变化。在第一个实验中，在不同时间检查了怀孕和哺乳期大鼠的BAT。在哺乳期后期（20天），BAT的总UPC含量从364±34微克降至32±9微克。哺乳期血清催乳素（PRL）浓度升高，在第10天时最高。当通过注射甲氧氯普胺（1.67mg/kg）刺激内源性PRL 5天时，BAT的UCP含量降低了50%。甲氧氯普胺的这种作用可被同时给予的溴隐亭（一种PRL分泌抑制剂）阻断。在给予甲氧氯普胺期间血清PRL浓度升高，但当同时给予甲氧氯普胺和溴隐亭时则不升高。我们得出结论，PRL可能是哺乳期抑制BAT的介质。
