Kather H
Int J Obes. 1981;5(6):659-63.
To elucidate the mechanisms of prostaglandin action in human adipose tissue the effects of prostaglandin E2 on isoproterenol-stimulated lipolysis in intact human fat cells and on adenylate cyclase activity of fat-cell ghosts were compared. In intact fat cells prostaglandin E2 caused a dose-dependent inhibition of isoproterenol -stimulated lipolysis which has a maximum of about 40 per cent; half maximal effects were observed at approximately 30 nmol/l prostaglandin E2. In broken cell preparation prostaglandin E2 displayed biphasic effects on adenylate cyclase activity with inhibition occurring in the nanomolar concentration range and stimulation at prostaglandin E2-concentrations above 1 mumol/l. The inhibitory component of prostaglandin E2-action was critically dependent on relatively high concentrations of GTP (greater than 1 mumol/l) and was augmented by sodium ions. The inhibitory component of prostaglandin E2-action on adenylate cyclase reflected the antilipolytic effects of this C-20 fatty acid in intact fat cells with respect to the effective concentration range and degree of inhibition suggesting that the antilipolytic effects of prostaglandins are in fact mediated via inhibition of human fat-cell adenylate cyclase.
为阐明前列腺素在人体脂肪组织中的作用机制，比较了前列腺素E2对完整人体脂肪细胞中异丙肾上腺素刺激的脂肪分解作用以及对脂肪细胞空壳腺苷酸环化酶活性的影响。在完整脂肪细胞中，前列腺素E2对异丙肾上腺素刺激的脂肪分解产生剂量依赖性抑制，最大抑制率约为40%；在前列腺素E2浓度约为30 nmol/l时观察到半数最大效应。在破碎细胞制剂中，前列腺素E2对腺苷酸环化酶活性表现出双相作用，在纳摩尔浓度范围内出现抑制，在前列腺素E2浓度高于1 μmol/l时出现刺激。前列腺素E2作用的抑制成分严重依赖于相对高浓度的GTP（大于1 μmol/l），并被钠离子增强。前列腺素E2对腺苷酸环化酶作用的抑制成分反映了这种C-20脂肪酸在完整脂肪细胞中的抗脂解作用，就有效浓度范围和抑制程度而言，提示前列腺素的抗脂解作用实际上是通过抑制人体脂肪细胞腺苷酸环化酶介导的。
