| Project/Area Number |
61570055
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
General physiology
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| Research Institution | School of Med.,Fukuoka University |
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Principal Investigator |
SAKAMOTO Yasuzi Associate Professor,School of Med.,Fukuoka University, 医学部, 助教授 (30078761)
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| Co-Investigator(Kenkyū-buntansha) |
ASANO Takashi Associate Professor,School of Med.,Fukuoka University, 医学部, 助教授 (00078792)
浅野 喬 福岡大学, 医学部, 助教授 (40122668)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Pancreatic B cells / Electrical activity / Ca channel / PN 202-791 / Carbachol / Clイオン / 膵β細胞 / Ca-agonist,Ca-antagonist / Ca-チャンネル / Ca依存性K電流 |
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| Research Abstract |
We examined the effects of carbachol and PN 202-791,affecting on Ca channel, on the burst-type activities induced by 11.2mM D-glucose in the pancreatic B cells of the mouse.The S-enatiomer prolonged the plateau duration of the slow wave by 200-300%,but it had no effect on an amplitude,a rate of rise and fall, of spike in concentration ranges from 5 X 10^<-8>M to 10^<ユ6>M.In the most cells,the electrical activities with small amplitude less than that of spike were distinctly observed on the plateau in the presence of the S-enatiomer. The R-enatiomer reduced the plateau duration and then blocked the electrical activities induced by D-glucose.
Carbachol(10^<-7>M-10^<-6>M)increased frequencies of spikes and slow waves induced by D-glucose(11.2mM).These efffects of carbachol may be due to membrane depolarization by the drug,since the increase in the frequencies of the slow waves and spikes depended on the membrane potential.This depolarization was marked in the B cells dissected from non-staved mouse,but was not in that from the strved mouse(one night).In the pretreated the B cells with carbachol in the Krebs solution,D-glucos did not induce the electrical activities in early period,but induced the membrane depolarization.
Thus we conclude that there are two type of Ca channel in the B cell membrane:one is related with geneses of spike potential and other is rather related with the plateau formation than spike,and that carbachol activates Ca channel resulting in increasing Ca-influx.Furthermore the membrane depolarization by carbachol may be related to CL^-,since the depolarization was reduced by CL-deficient solution.However further experiments are needed to evaluate the precise role of CL-in the electrical activities.
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