Davidović V, Radojicić R, Cvijić G, Durasević S, Petrović N
Institute of Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Yugoslavia.
Comp Biochem Physiol C Pharmacol Toxicol Endocrinol. 1997 Jun;117(2):181-6. doi: 10.1016/s0742-8413(97)00065-0.
The effects of different doses of insulin (INS) (0.4 or 4.0 IU/kg body mass, i.p., for 3 hr) and 6-hydroxydopamine (6-HDA) (100 mg/kg., i.p.) on the activities of antioxidant enzymes--copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), catalase (CAT) and catecholamine degrading enzyme monoamine oxidase (MAO-A)--in the rat interscapular brown adipose tissue (IBAT) were studied. In vivo 6-HDA administration, which induces the destruction of sympathetic nerves, markedly reduced IBAT CuZnSOD activity but did not change MnSOD and CAT activities. However, the low dose of INS, which did not induce hypoglycemia, significantly increased the activity of both IBAT mitochondrial enzymes (MnSOD and MAO-A) of control rats. This INS effect on MnSOD was abolished by 6-HDA. On the contrary, CuZnSOD activity was markedly reduced under the influence of INS in both control and 6-HDA-treated rats, whereas for the maintenance of the control level of this enzyme activity, the intact sympathetic nervous system (SNS) is necessary. INS, independent of the dose applied, did not affect CAT activity in control rats, whereas only low INS dose increased the activity of this enzyme in 6-HDA-treated rats. The results indicate that the stimulatory effect of INS on the IBAT mitochondrial enzymes studied is dose dependent and in the case of MnSOD is mediated by SNS. However, the depression in the activity of CuZnSOD is independent of the above-mentioned factors.
研究了不同剂量胰岛素（INS）（0.4或4.0国际单位/千克体重，腹腔注射，持续3小时）和6-羟基多巴胺（6-HDA）（100毫克/千克，腹腔注射）对大鼠肩胛间棕色脂肪组织（IBAT）中抗氧化酶——铜锌超氧化物歧化酶（CuZnSOD）、锰超氧化物歧化酶（MnSOD）、过氧化氢酶（CAT）以及儿茶酚胺降解酶单胺氧化酶（MAO-A）活性的影响。体内给予6-HDA可诱导交感神经破坏，显著降低IBAT的CuZnSOD活性，但不改变MnSOD和CAT活性。然而，低剂量的INS未诱导低血糖，却显著增加了对照大鼠IBAT两种线粒体酶（MnSOD和MAO-A）的活性。6-HDA消除了INS对MnSOD的这种作用。相反，在对照大鼠和6-HDA处理的大鼠中，INS均显著降低CuZnSOD活性，而要维持该酶活性的对照水平，则完整的交感神经系统（SNS）是必需的。INS无论应用何种剂量，均不影响对照大鼠的CAT活性，而仅低剂量INS可增加6-HDA处理大鼠中该酶的活性。结果表明，INS对所研究的IBAT线粒体酶的刺激作用具有剂量依赖性，对于MnSOD而言，其作用由SNS介导。然而，CuZnSOD活性的降低与上述因素无关。
