钙离子在激动剂引起豚鼠胆囊肌条收缩中的作用

本工作采用肌肉等张收缩记录法和 cGMP、cAMP 的放射免疫测定法,来研究乙酰胆碱、碳酰胆碱和胃肠激素(雨蛙肽)引起豚鼠胆囊肌条(GBMS)收缩中 Ca~(2+)的作用。结果表明,在有钙液中 GBMS 收缩较无钙液中强。在无钙液、在 EDTA-零钙液或异搏定-Krebs液中,GBMS 对激动剂的收缩反应降低到对照组的30%左右(P<0.01)。异搏定使碳酰胆碱刺激的 GBMS 内 cGMP 和 CAMP 含量降低(P<0.01或0.05)。这些结果提示,在激动剂引起胆囊肌条收缩中,细胞内、外钙离子均参与作用,从而影响胆囊肌条收缩。

EFFECTS OF CALCIUM ION ON CONTRACTILE RESPONSE OF GUINEA-PIG GALLBLADDER MUSCLE STRIP TO AGONISTS

The effects of calcium ion on the contractile response of gallbladder musclestrip(GBMS)in guinea pigs to acetylcholine,carbachol and caerulein were in-vestigated by method of isotonic contraction and by RIA of cGMP and cAMPin the tissue.It was shown that the contractile response of GBMS to these ago-nists was stronger in Krebs solution than that in the calcium-free solution.In calcium-free solution,EDTA-zero calcium solution or verapamil-Krebs Solu-tion,the contractile response of GBMD was decreased to about 30% of the con-trol(P<0.01).Verapamil significantly decreased carbochol induced enhance-ment of cGMP and cAMP of gallbladder tissue(P<0.01 or 0.05).The resultssuggest that both extra-and intra-cellular calcium take part in the contractileresponse of GBMS to agonists.