Egawa M, Yoshimatsu H, Bray G A
Department of Medicine, University of Southern California School of Medicine, Los Angeles 90033.
Am J Physiol. 1993 Jan;264(1 Pt 2):R109-15. doi: 10.1152/ajpregu.1993.264.1.R109.
beta-Endorphin was injected into the third cerebroventricle to investigate its effects on sympathetic nerve activity to interscapular brown adipose tissue (IBAT) in rats. Multiunit discharges of sympathetic nerves to IBAT were recorded electrophysiologically in anesthetized rats. The intracerebroventricular injection of beta-endorphin (125, 250, and 500 pmol/rat in 10 microliters) suppressed sympathetic nerve activity in a dose-related fashion (-23.9 +/- 20.4, -38.7 +/- 7.1, and -66.7 +/- 7.6% 30 min after injection) compared with preinjection baseline. N-acetyl-beta-endorphin (250 pmol) had no effect on sympathetic nerve activity to IBAT. The intraperitoneal injection of naloxone (5.0 mg/rat) did not affect sympathetic nerve activity, but preinjection of naloxone inhibited the suppressive effect of intracerebroventricular injection of beta-endorphin (250 pmol). We conclude that the intracerebroventricular administration of beta-endorphin suppressed the sympathetic nerve activity to IBAT through opioid receptors. The results of this experiment are consistent with the hypothesis that beta-endorphin has a reciprocal effect on food intake and the sympathetic nervous system.
将β-内啡肽注入第三脑室，以研究其对大鼠肩胛间棕色脂肪组织（IBAT）交感神经活动的影响。在麻醉的大鼠中，通过电生理学方法记录了支配IBAT的交感神经的多单位放电。脑室内注射β-内啡肽（10微升中含125、250和500皮摩尔/大鼠）以剂量相关的方式抑制交感神经活动（注射后30分钟分别为-23.9±20.4、-38.7±7.1和-66.7±7.6%），与注射前基线相比。N-乙酰-β-内啡肽（250皮摩尔）对支配IBAT的交感神经活动没有影响。腹腔注射纳洛酮（5.0毫克/大鼠）不影响交感神经活动，但注射纳洛酮预处理可抑制脑室内注射β-内啡肽（250皮摩尔）的抑制作用。我们得出结论，脑室内给予β-内啡肽通过阿片受体抑制了对IBAT的交感神经活动。本实验结果与β-内啡肽对食物摄入和交感神经系统具有相互作用的假说一致。
