Nishizawa Y, Bray G A
J Clin Invest. 1978 Mar;61(3):714-21. doi: 10.1172/JCI108984.
We have explored the effects of ventromedial hypothalamic lesions on the mobilization of free fatty acids in rats exposed to several stresses. The rise in free fatty acids and glycerol in response to norepinephrine had the same time-course and dose-response characteristics in the sham-operated and lesioned animals, indicating comparable degrees of peripheral responsiveness to this hormone. Forced swimming significantly lowered insulin and increased glycerol and free fatty acids more in control than in ventromedial hypothalamic-lesioned rats. During fasting, the rise in glycerol and free fatty acids was smaller in the lesioned rats, but the fall in insulin was greater. Exposure to cold raised fatty acids and glycerol more in the control than in the sham-operated animals, but had no significant effect on plasma insulin or glucose concentration. Injection of 2-deoxyglucose was done on lesioned or control rats with intact or removed adrenal medullas. The rise in free fatty acids and glycerol was less in the lesioned rats than in the controls, and was not affected by adrenodemedullation. The rise in glucose, however, was completely blocked in the adrenodemedullated rats. Changes in insulin were small and not statistically significant. The reduced mobilization of fatty acids from adipose tissue depots after ventromedial hypothalamic injury is consistent with the hypothesis that the ventromedial hypothalamic region serves to modulate activation of the sympathetic nervous system.
我们研究了下丘脑腹内侧核损伤对暴露于多种应激状态下的大鼠游离脂肪酸动员情况的影响。在假手术组和损伤组动物中，去甲肾上腺素引起的游离脂肪酸和甘油水平升高具有相同的时程和剂量反应特征，这表明两组动物对该激素的外周反应程度相当。强迫游泳使对照组大鼠的胰岛素水平显著降低，甘油和游离脂肪酸水平升高幅度大于下丘脑腹内侧核损伤组大鼠。禁食期间，损伤组大鼠甘油和游离脂肪酸的升高幅度较小，但胰岛素的下降幅度更大。与假手术组动物相比，对照组动物暴露于寒冷环境后脂肪酸和甘油水平升高幅度更大，但对血浆胰岛素或葡萄糖浓度无显著影响。对肾上腺髓质完整或切除的损伤组或对照组大鼠注射2-脱氧葡萄糖。损伤组大鼠游离脂肪酸和甘油的升高幅度小于对照组，且不受肾上腺髓质切除的影响。然而，肾上腺髓质切除的大鼠葡萄糖升高完全受阻。胰岛素的变化较小且无统计学意义。下丘脑腹内侧核损伤后脂肪组织中脂肪酸动员减少，这与下丘脑腹内侧核区域调节交感神经系统激活的假说一致。
