Brito S M R C, Moura M A F, Kawashita N H, Festuccia W T L, Garófalo M A R, Kettelhut I C, Migliorini R H
Department of Physiology, School of Medicine, University of São Paulo, Brazil.
Can J Physiol Pharmacol. 2005 Jun;83(6):477-82. doi: 10.1139/y05-035.
We have previously shown that in vivo lipogenesis is markedly reduced in liver, carcass, and in 4 different depots of adipose tissue of rats adapted to a high protein, carbohydrate-free (HP) diet. In the present work, we investigate the activity of enzymes involved in lipogenesis in the epididymal adipose tissue (EPI) of rats adapted to an HP diet before and 12 h after a balanced diet was introduced. Rats fed an HP diet for 15 days showed a 60% reduction of EPI fatty acid synthesis in vivo that was accompanied by 45%-55% decreases in the activities of pyruvate dehydrogenase complex, ATP-citrate lyase, acetyl-CoA carboxylase, glucose-6-phosphate dehydrogenase, and malic enzyme. Reversion to a balanced diet for 12 h resulted in a normalization of in vivo EPI lipogenesis, and in a restoration of acetyl-CoA carboxylase activity to levels that did not differ significantly from control values. The activities of ATP-citrate lyase and pyruvate dehydrogenase complex increased to about 75%-86% of control values, but the activities of glucose-6-phosphate dehydrogenase and malic enzyme remained unchanged 12 h after diet reversion. The data indicate that in rats, the adjustment of adipose tissue lipogenic activity is an important component of the metabolic adaptation to different nutritional conditions.
我们之前已经表明，在适应高蛋白、无碳水化合物（HP）饮食的大鼠的肝脏、胴体以及4种不同脂肪组织库中，体内脂肪生成显著减少。在本研究中，我们调查了适应HP饮食的大鼠在引入均衡饮食之前和之后12小时附睾脂肪组织（EPI）中参与脂肪生成的酶的活性。喂食HP饮食15天的大鼠体内EPI脂肪酸合成减少了60%，同时丙酮酸脱氢酶复合体、ATP-柠檬酸裂解酶、乙酰辅酶A羧化酶、葡萄糖-6-磷酸脱氢酶和苹果酸酶的活性降低了45%-55%。恢复到均衡饮食12小时导致体内EPI脂肪生成正常化，并且乙酰辅酶A羧化酶活性恢复到与对照值无显著差异的水平。ATP-柠檬酸裂解酶和丙酮酸脱氢酶复合体的活性增加到对照值的约75%-86%，但饮食恢复12小时后葡萄糖-6-磷酸脱氢酶和苹果酸酶的活性保持不变。数据表明，在大鼠中，脂肪组织脂肪生成活性的调节是对不同营养条件代谢适应的重要组成部分。
