Anderson A J, Duncan G P, Spedding M, Patmore L
Syntex Research Centre, Edinburgh, Scotland.
J Cardiovasc Pharmacol. 1990 Oct;16(4):681-3. doi: 10.1097/00005344-199010000-00023.
Pretreatment of embryonic chick cardiac myocytes with pertussis toxin (1-2.5 micrograms ml-1 for 22 h) abolished the negative chronotropic effects of carbachol but not the positive inotropic effects of Bay K 8644. Neither guanosine 5'-O-3-thiotriphosphate (GTP gamma S 500 microM intracellularly), nor pertussis toxin (0.5-1 microgram ml-1 for 22 h) modified the agonist effects of Bay K 8644 on calcium channel currents recorded under whole-cell voltage clamp. These findings indicate that pertussis-sensitive guanine nucleotide binding (G)-proteins does not modulate the effects of calcium channel activators in embryonic chick cardiac myocytes.
用百日咳毒素（1 - 2.5微克/毫升，处理22小时）预处理鸡胚心肌细胞，可消除卡巴胆碱的负性变时作用，但不影响Bay K 8644的正性变力作用。细胞内500微摩尔的5'-O-3-硫代三磷酸鸟苷（GTPγS）和百日咳毒素（0.5 - 1微克/毫升，处理22小时）均未改变Bay K 8644对全细胞膜片钳记录的钙通道电流的激动剂作用。这些发现表明，百日咳敏感的鸟嘌呤核苷酸结合（G）蛋白不调节鸡胚心肌细胞中钙通道激活剂的作用。
