Poggioli J, Leslie B A, McKinney J S, Weiss S J, Putney J W
J Pharmacol Exp Ther. 1982 Apr;221(1):247-53.
The effects of ionomycin (SQ 23,377), a carboxylic acid Ca-ionophore, on the rat parotid acinar cell were investigated. Ionomycin stimulated 86Rb efflux from parotid slices and was substantially more potent and efficacious than the Ca-ionophore, A-23187. The release of 86Rb was dependent on the concentration of ionomycin and of Ca. Ionomycin also stimulated 22Na uptake and 3H-protein secretion, but did not stimulate the incorporation of 32PO4 into phosphatidylinositol. These observations are consistent with an action of ionomycin in increasing cytosolic Ca by acting as an ionophore and not involving endogenous receptors. Pretreatment with ionomycin inhibited the transient, Ca-independent responses to carbachol or physalaemin. When ionomycin was added to parotid cells pre-equilibrated with 45Ca, a net loss of radiocalcium was observed. These observations suggest that ionomycin can release the receptor-regulated cellular Ca pool. Morphological studies did not reveal any nonspecific deleterious effects in the cells after incubation with 2.67 microM ionomycin.
研究了羧酸钙离子载体离子霉素（SQ 23,377）对大鼠腮腺腺泡细胞的影响。离子霉素刺激腮腺切片中86Rb外流，其效力和效果比钙离子载体A - 23187强得多。86Rb的释放取决于离子霉素和钙的浓度。离子霉素还刺激22Na摄取和3H - 蛋白质分泌，但不刺激32PO4掺入磷脂酰肌醇。这些观察结果与离子霉素作为离子载体增加胞质钙的作用一致，且不涉及内源性受体。用离子霉素预处理可抑制对卡巴胆碱或毒扁豆碱的短暂、钙非依赖性反应。当将离子霉素添加到用45Ca预平衡的腮腺细胞中时，观察到放射性钙的净损失。这些观察结果表明离子霉素可以释放受体调节的细胞钙库。形态学研究未发现用2.67 microM离子霉素孵育后细胞有任何非特异性有害影响。
