Y A Mei, L X Huang, H Wei, J T Sun, H Q Zhou, Z H Zhang
{"title":"Characterization of outward potassium current in embryonic chick heart cells.","authors":"Y A Mei, L X Huang, H Wei, J T Sun, H Q Zhou, Z H Zhang","doi":"","DOIUrl":null,"url":null,"abstract":"<p><strong>Aim: </strong>To characterize a voltage-dependent outward K+ current in cultured heart cells of 14-16-day-old embryos of yellow chick.</p><p><strong>Methods: </strong>The patchclamp technique in the whole-cell configuration was used.</p><p><strong>Results: </strong>The kinetics and the pharmacology of the outward K+ current in our cell mold were different from those described in white chick. Like the calcium-activated K+ current, blocker of calcium channel, CdCl2, eliminated the current of more than 95%. Isoproterenol provoked an increase of peak amplitude (137% +/- 47%, n = 16 cells) and acceleration of activation kinetics in the outward K+ current (the time reaching a peak current reduced from 36 ms +/- 10 ms to 16 ms +/- 9 ms). This effect of isoproterenol was mimiced by cAMP. In addition, a frequency-dependent decrease in peak amplitude of the current occurred after cAMP-induced phosphorylation.</p><p><strong>Conclusion: </strong>There are species- and/or cell-type-specific difference in the K+ channels properties. In embryonic yellow chick heart cells, the phospholation of channel could not only modulate the activation kinetic properties of the calcium-activated potassium channel, but also change their recovery kinetics.</p>","PeriodicalId":24002,"journal":{"name":"Zhongguo yao li xue bao = Acta pharmacologica Sinica","volume":"20 4","pages":"303-7"},"PeriodicalIF":0.0000,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Zhongguo yao li xue bao = Acta pharmacologica Sinica","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Aim: To characterize a voltage-dependent outward K+ current in cultured heart cells of 14-16-day-old embryos of yellow chick.
Methods: The patchclamp technique in the whole-cell configuration was used.
Results: The kinetics and the pharmacology of the outward K+ current in our cell mold were different from those described in white chick. Like the calcium-activated K+ current, blocker of calcium channel, CdCl2, eliminated the current of more than 95%. Isoproterenol provoked an increase of peak amplitude (137% +/- 47%, n = 16 cells) and acceleration of activation kinetics in the outward K+ current (the time reaching a peak current reduced from 36 ms +/- 10 ms to 16 ms +/- 9 ms). This effect of isoproterenol was mimiced by cAMP. In addition, a frequency-dependent decrease in peak amplitude of the current occurred after cAMP-induced phosphorylation.
Conclusion: There are species- and/or cell-type-specific difference in the K+ channels properties. In embryonic yellow chick heart cells, the phospholation of channel could not only modulate the activation kinetic properties of the calcium-activated potassium channel, but also change their recovery kinetics.