Lobo M V, Mendoza R R, Marusic E T
Department of Physiology and Biophysics, Faculty of Medicine, University of Chile, Santiago.
J Steroid Biochem. 1990 Jan;35(1):29-33. doi: 10.1016/0022-4731(90)90141-e.
In order to elucidate the possible role in glomerulosa cells of diacylglycerol released by angiotensin II we have studied the action of a synthetic diacylglycerol, sn-1,2-dioctanoylglycerol (DiC8), on aldosterone production and potassium permeability in bovine adrenal cells. DiC8 elicited an increase in 86Rb efflux from cells previously equilibrated with the isotope. The action of DiC8 on the rate coefficient for 86Rb efflux was similar to that previously described for angiotensin II (Am. J. Physiol. 254 (1988) E144-149), i.e. DiC8 induced an immediate increase in 86Rb efflux followed by a sustained decrease in potassium permeability. This DiC8 induced inhibition was observed even in the presence of depolarizing concentrations of potassium. The effect of DiC8 on aldosterone secretion from adrenal glomerulosa cells was measured using a perifusion system. DiC8 (300 microM) caused a significant increase of aldosterone production, comparable to that seen with angiotensin II (100 nM). These results indicate that DiC8 has similar effects to angiotensin II on both potassium permeability and steroidogenesis, which suggests that activation of protein kinase C is involved in the changes of ionic permeability induced by this hormone in bovine adrenal glomerulosa cells.
为了阐明血管紧张素II释放的二酰基甘油在球状带细胞中的可能作用，我们研究了合成二酰基甘油sn-1,2-二辛酰甘油（DiC8）对牛肾上腺细胞醛固酮分泌和钾通透性的作用。DiC8使先前用该同位素平衡的细胞中86Rb外流增加。DiC8对86Rb外流速率系数的作用与先前描述的血管紧张素II的作用相似（《美国生理学杂志》254 (1988) E144 - 149），即DiC8诱导86Rb外流立即增加，随后钾通透性持续降低。即使在存在去极化浓度钾的情况下，也观察到这种DiC8诱导的抑制作用。使用灌流系统测量DiC8对肾上腺球状带细胞醛固酮分泌的影响。DiC8（300 microM）使醛固酮分泌显著增加，与血管紧张素II（100 nM）的作用相当。这些结果表明，DiC8在钾通透性和类固醇生成方面具有与血管紧张素II相似的作用，这表明蛋白激酶C的激活参与了该激素在牛肾上腺球状带细胞中诱导的离子通透性变化。
