Lazzarini S J, Wade G N
Neuroscience and Behavior Program, University of Massachusetts, Amherst 01003.
Am J Physiol. 1991 Jan;260(1 Pt 2):R47-51. doi: 10.1152/ajpregu.1991.260.1.R47.
Two experiments examined the role of the sympathetic nerves in estradiol-induced fat pad weight losses in ovariectomized (OVX) rats. Rats were OVX, and the retroperitoneal white adipose tissue (RWAT) was unilaterally denervated 4 wk later. After 14 days of treatment with estradiol benzoate (EB, 2 micrograms/day), the intact pads lost 23% more weight than the denervated pads. There was no effect of denervation on fat pad weight or on cytosol estrogen receptor concentration in RWAT in the animals treated with sesame oil vehicle. These data suggest that the sympathetic nerves play a role in estrogen-induced reductions in fat pad weight but not via changes in adipose tissue cytosol estrogen receptors. A second experiment examined whether estradiol-induced fat pad weight losses are accompanied by increased norepinephrine (NE) turnover, an index of sympathetic activity, in adipose tissue. Rats were OVX and treated with EB or sesame oil vehicle. NE turnover was assessed by measuring the decline of tissue NE over time after injection of alpha-methyl-p-tyrosine, an inhibitor of tyrosine hydroxylase activity and thus NE biosynthesis. NE turnover in RWAT, but not heart, was significantly greater in animals treated with EB, suggesting that estradiol decreases fat pad weight in part by increasing sympathetic nervous system activity. It is possible that estradiol acts in the brain to regulate the activity of the sympathetic nerves to white adipose tissue and peripherally to alter adipose tissue responsiveness to catecholamines.
两项实验研究了交感神经在去卵巢（OVX）大鼠中雌二醇诱导的脂肪垫重量减轻中的作用。大鼠接受去卵巢手术，4周后对其腹膜后白色脂肪组织（RWAT）进行单侧去神经支配。在用苯甲酸雌二醇（EB，2微克/天）治疗14天后，完整的脂肪垫比去神经支配的脂肪垫多减轻了23%的重量。在用芝麻油载体处理的动物中，去神经支配对RWAT中的脂肪垫重量或细胞质雌激素受体浓度没有影响。这些数据表明，交感神经在雌激素诱导的脂肪垫重量减轻中起作用，但不是通过改变脂肪组织细胞质雌激素受体来实现的。第二项实验研究了雌二醇诱导的脂肪垫重量减轻是否伴随着脂肪组织中去甲肾上腺素（NE）周转率的增加，NE周转率是交感神经活动的一个指标。大鼠接受去卵巢手术，并用EB或芝麻油载体进行处理。通过测量注射α-甲基-p-酪氨酸（一种酪氨酸羟化酶活性抑制剂，从而抑制NE生物合成）后组织NE随时间的下降来评估NE周转率。用EB处理的动物中，RWAT而非心脏中的NE周转率显著更高，这表明雌二醇部分通过增加交感神经系统活动来降低脂肪垫重量。雌二醇可能在大脑中起作用，调节交感神经对白色脂肪组织的活性，并在外周改变脂肪组织对儿茶酚胺的反应性。
