Van Meel J C, Haigh R M
Department of Biochemistry, Dr Karl Thomae GmbH, Biberach an der Riss, Germany.
Eur J Pharmacol. 1993 Nov 15;247(3):357-8. doi: 10.1016/0922-4106(93)90207-p.
Mastoparan preferentially activates the G protein Gi in transmembrane signalling pathways. In heart tissue Gi couples receptors to negative inotropy so we have examined the effect of mastoparan on contractility in cardiac myocytes electrically stimulated at 0.5 Hz. Mastoparan (10(-5) mol/l) caused a time-dependent increase in cell shortening to a maximum of 83.7 +/- 18.0% (n = 7) of the resting cell length at between 4 and 7 min. This could be the result of either stimulation of other G proteins or the release of beta gamma subunits from Gi which activate phospholipase C.
马斯托帕兰在跨膜信号通路中优先激活G蛋白Gi。在心脏组织中，Gi将受体与负性肌力作用偶联，因此我们研究了马斯托帕兰对以0.5Hz进行电刺激的心肌细胞收缩性的影响。马斯托帕兰（10^(-5)mol/L）导致细胞缩短随时间增加，在4至7分钟时达到最大缩短值，为静息细胞长度的83.7±18.0%（n = 7）。这可能是刺激其他G蛋白的结果，也可能是Gi释放出βγ亚基激活磷脂酶C的结果。
