阴离子和阳离子对心脏腺苷酸环化酶的作用：与异丙肾上腺素和鸟苷三磷酸的相互作用。

The effect of anions and cations on cardiac adenylate cyclase: interactions with isoprenaline and GTP.

作者信息

Leclerc L, Harding S E, Harris P

出版信息

Biochem Biophys Res Commun. 1984 Jan 30;118(2):561-6. doi: 10.1016/0006-291x(84)91339-1.

Abstract

Anions stimulated rabbit heart adenylate cyclase in the order chloride greater than phosphate greater than acetate, while the cations sodium and potassium had little effect. Activation by KCI was multiplicative with that of fluoride. Isoprenaline (10(-4) M) and GTP(10(-4) M) stimulated the cyclase independently, and their combined effects were multiplicative. GTP stimulated less than chloride but more than acetate. Activation by chloride or acetate was more than additive with that by GTP. The effect of isoprenaline was reduced in the presence of chloride or acetate, and this reduction was not modified by sodium or potassium. It was concluded that ionic influence may be biologically important in modifying cyclase activity and the extent of beta-receptor stimulation.

摘要

阴离子对兔心脏腺苷酸环化酶的刺激作用顺序为

氯离子＞磷酸根离子＞醋酸根离子，而阳离子钠和钾的影响很小。氯化钾的激活作用与氟化物的激活作用呈相乘关系。异丙肾上腺素（10⁻⁴ M）和鸟苷三磷酸（10⁻⁴ M）可独立刺激环化酶，它们的联合作用呈相乘关系。鸟苷三磷酸的刺激作用小于氯离子但大于醋酸根离子。氯离子或醋酸根离子的激活作用与鸟苷三磷酸的激活作用呈相加以上的关系。在有氯离子或醋酸根离子存在时，异丙肾上腺素的作用减弱，且这种减弱不受钠或钾的影响。得出的结论是，离子影响在调节环化酶活性和β受体刺激程度方面可能具有生物学重要性。