血管钠素肽对大鼠心室肌细胞L-型钙通道电流的影响  

THE EFFECT OF VASONATRIN PEPTIDE ON L TYPE CALCIUM CHANNELS IN RAT SINGLE VENTRICULAR MYOCYTES

作　　者：程树亮[1] 牛国保[1] 王跃民[1] 冯华松[1] 裴建明[1] 

机构地区：[1]第四军医大学基础部生理教研室

出　　处：《中国应用生理学杂志》1999年第2期107-110,共4页Chinese Journal of Applied Physiology

基　　金：国家自然科学基金

摘　　要：目的和方法：采用膜片钳全细胞记录方式观察血管钠素肽（ＶＮＰ）对大鼠单个心室肌细胞Ｌ型钙通道电流（ＩＣａ，Ｌ）的影响。结果：当心室肌细胞由保持电压４０ｍＶ除极到０ｍＶ时，０．１，０．２和０．４μｍｏｌ／Ｌ的ＶＮＰ分别使ＩＣａ，Ｌ内向电流峰值降低３１．０５％，４６．９５％和６０．７５％。该抑制作用与ＩＣａ，Ｌ的ｒｕｎｄｏｗｎ现象无关，且对ＩＣａ，Ｌ的最大激活电位无明显影响。当ＩＣａ，Ｌ被异丙肾上腺素（１０－７ｍｏｌ／Ｌ）预先激活后，ＶＮＰ（０．２μｍｏｌ／Ｌ）仍可使ＩＣａ，Ｌ电流峰值下降１８．２３％。结论：ＶＮＰ对大鼠心室肌细胞ＩＣａ，Ｌ具有明确的抑制作用，该作用可能是ＶＮＰ发挥其心血管效应的离子通道机制之一。Aim and Methods: The effect of external application of vasonatrin peptide (VNP) on L type calcium current (T Ca,L ) was stu died in single cells isolated from rat ventricle using the whole cell patch clamp technique.Results: It was found that 0.1, 0. 2 and 0.4 μmol/L VNP reduced I Ca,L peak currernt by an average of 31. 05%, 46. 95%,60. 75% respectively when the ventricular myocytes were depolarized to 0 mV from the holding potential ( 40 mV). This inhibitory effect of VNP on I Ca,L had no relation with the“rundown”phenomenon and little effect on the maxium activing potential of I Ca,L . When I Ca,L was increased by isoprenaline (10 -7 mol/L) preferentially, VNP (0. 2 μmol/L) could still decrease I Ca,L peak current by 18. 23%.Conclusion: These results indicate that VNP do have inhibitory effect on I Ca,L and this effect might be one of the mechanisms by which VNP regulates cardiovascular system. 〖HS1*2]

关 键 词：利钠尿肽 血管钠素肽 L-型钙电流 

分 类 号：R331.38[医药卫生—人体生理学] Q516[医药卫生—基础医学]