Morimoto C, Tsujita T, Sumida M, Okuda H
Second Department of Medical Biochemistry, Central Research Laboratory, School of Medicine, Ehime University, Shigenobu-cho, Onsen-gun, Ehime, 791-0295, Japan.
Biochem Biophys Res Commun. 2000 Aug 11;274(3):631-4. doi: 10.1006/bbrc.2000.3190.
The relationship between isoproterenol-induced lipolysis and the phosphorylation of perilipin and hormone-sensitive lipase (HSL) was examined using cell-free systems consisting of lipid droplets isolated from rat fat cells and HSL, and/or trioleoylglycerol emulsified with gum arabic and HSL. Isoproterenol was found to stimulate lipolysis in the cell-free system with the lipid droplets without an increase in the phosphorylation of either perilipin or HSL. On the other hand, no stimulation of lipolysis was found in the cell-free system containing lipid droplets despite increases in the phosphorylation of perilipin and HSL. In the cell-free system consisting of trioleoylglycerol emulsified with gum arabic and HSL, neither isoproterenol nor increases in the phosphorylation of perilipin and HSL accelerated lipolysis. These results suggest that isoproterenol-induced lipolysis may not be mediated through the phosphorylation of perilipin and HSL, and may rather be dependent on the substrate of HSL.
使用由从大鼠脂肪细胞分离的脂滴和激素敏感性脂肪酶（HSL）组成的无细胞系统，以及/或者用阿拉伯胶乳化的三油酰甘油和HSL，研究了异丙肾上腺素诱导的脂肪分解与围脂滴蛋白和激素敏感性脂肪酶（HSL）磷酸化之间的关系。发现在含有脂滴的无细胞系统中，异丙肾上腺素可刺激脂肪分解，而围脂滴蛋白或HSL的磷酸化均未增加。另一方面，尽管围脂滴蛋白和HSL的磷酸化增加，但在含有脂滴的无细胞系统中未发现脂肪分解受到刺激。在用阿拉伯胶乳化的三油酰甘油和HSL组成的无细胞系统中，异丙肾上腺素以及围脂滴蛋白和HSL磷酸化的增加均未加速脂肪分解。这些结果表明，异丙肾上腺素诱导的脂肪分解可能不是通过围脂滴蛋白和HSL的磷酸化介导的，而可能更依赖于HSL的底物。
