摘要
实验以单个Wistar大鼠胰腺 β细胞为对象 ,用穿孔膜片箝和细胞贴附式记录技术研究ATP敏感K+通道 (KATP)、延迟整流型K+通道 (KDR)、Ca2 +通道和Na+通道的有关特性。结果表明 :( 1)KATP通道的内流电导约 6 5pS ,外流电导约 31pS ,反转电位在 - 6 0mV左右 ;( 2 )KDR通道在延迟 2 0ms后达到最大激活 ,KDR电流约为KATP的1/ 3;( 3)钙电流在 0mV左右达到 40～ 6 0pA的峰值 ,L 型钙通道是大鼠 β细胞主要的钙通道 ,其上还含另一种高电压激活的钙通道 ;( 4)约有一半的 β细胞有明显的钠电流 ,钠通道在 10mV左右达到 2 0 0～ 40
Using perforated and cell attached patch clamp techniques, the characteristics of ATP sensitive K + channels (K ATP ), delayed rectifier K + channels (K DR ), Ca 2+ and Na + channels on single rat pancreatic β cell membranes were studied. The results showed that (1) the efflux and influx conductance of K ATP channels was about 31 and 65 pS respectively, and the reversal potential of K ATP was about -60 mV; (2) K DR was activated completely after a latency of 20 ms, and K DR was about 1/3 of K ATP ; (3) whole cell Ca 2+ current reached a peak (40～60 pA) at 0 mV; L type Ca 2+ channel was the main Ca 2+ channel in β cells, but other types of high voltage activated Ca 2+ channels existed as well; and (4) whole cell Na + current reached a peak (200～400 pA) at 10 mV; but the expression level of Na + channel in β cells varied among the cells. About half of the β cells virtually had no Na + currents.
出处
《生理学报》
CAS
CSCD
北大核心
2000年第2期98-102,共5页
Acta Physiologica Sinica
基金
SupportedbyCNSFgrants 39525009(ZZ)69571014(QAL)TheLiFoundationHeritagePrize(USA)andCAS"10 0LeadingScientistsP
