Blackmore P F, Augert G
Department of Pharmacology, Eastern Virginia Medical School, Norfolk.
Cell Calcium. 1989 Nov-Dec;10(8):561-7. doi: 10.1016/0143-4160(89)90018-3.
Some studies have indicated that insulin was able to increase the level of free cytosolic calcium in adipocytes [e.g. 7]. The present study was designed to examine this phenomenon. Insulin did not increase free cytosolic calcium, however oxytocin, vasopressin, alpha-adrenergic agonists and ATP did increase free cytosolic calcium in adipocytes. Other agonists which also did not alter calcium were epidermal growth factor, angiotensin II, glucagon, and beta-adrenergic agonists. The effect of oxytocin at increasing free cytosolic calcium was inhibited by activation of protein kinase C with phorbol 12-myristate 13-acetate and by ADP ribosylation of a Gi like protein with islet activating protein. The hormones that did increase cytosolic free calcium did so by mobilizing internal calcium and by promoting calcium influx. Even though insulin did not increase free cytosolic calcium, it was able to attenuate the alpha-adrenergic mediated increase in cytosolic free calcium. The fact that certain hormones can increase the level of the second messenger calcium in adipocytes implies that it may be a key intracellular regulator of adipocyte function as it is in many other tissues.
一些研究表明，胰岛素能够提高脂肪细胞中游离胞质钙的水平[例如7]。本研究旨在检验这一现象。胰岛素并未增加游离胞质钙，但催产素、血管加压素、α-肾上腺素能激动剂和ATP确实增加了脂肪细胞中游离胞质钙。其他同样未改变钙水平的激动剂有表皮生长因子、血管紧张素II、胰高血糖素和β-肾上腺素能激动剂。用佛波醇12-肉豆蔻酸酯13-乙酸酯激活蛋白激酶C以及用胰岛激活蛋白对一种类Gi蛋白进行ADP核糖基化，可抑制催产素增加游离胞质钙的作用。确实增加胞质游离钙的激素是通过动员细胞内钙和促进钙内流来实现的。尽管胰岛素并未增加游离胞质钙，但它能够减弱α-肾上腺素能介导的胞质游离钙增加。某些激素能够提高脂肪细胞中第二信使钙的水平，这一事实表明，钙可能是脂肪细胞功能的关键细胞内调节因子，就像在许多其他组织中一样。
