Interaction between Ca2+ channel blockers and isoproterenol on L-type Ca2+ current in canine ventricular cardiomyocytes

被引：4

作者：

Farkas, V. ^{[1
]}

Szentandrassy, N. ^{[2
]}

Barandi, L. ^{[2
]}

Hegyi, B. ^{[2
]}

Ruzsnavszky, F. ^{[2
]}

Ruzsnavszky, O. ^{[2
]}

Horvath, B. ^{[2
]}

Banyasz, T. ^{[2
]}

Magyar, J. ^{[2
]}

Marton, I. ^{[1
]}

Nanasi, P. P. ^{[2
]}

机构：

[1] Univ Debrecen, Dept Dent, H-4012 Debrecen, Hungary

[2] Univ Debrecen, Dept Physiol, H-4012 Debrecen, Hungary

来源：

ACTA PHYSIOLOGICA | 2012年 / 206卷 / 01期

关键词：

adrenergic activation; calcium channel blockers; calcium current; dog myocytes; isoproterenol; patch clamp; CALCIUM-CHANNELS; CARDIAC MYOCYTES; ACTION-POTENTIALS; HEART-CELLS; VOLTAGE; MODULATION; RAT; SENSITIVITY; INHIBITION; SUBUNIT;

D O I：

10.1111/j.1748-1716.2012.02448.x

中图分类号：

Q4 [生理学];

学科分类号：

071003 ;

摘要：

Aim The aim of this work was to study antagonistic interactions between the effects of various types of Ca2+ channel blockers and isoproterenol on the amplitude of L-type Ca2+ current in canine ventricular cells. Methods Whole-cell version of the patch clamp technique was used to study the effect of isoproterenol on Ca2+ current in the absence and presence of Ca2+ channelblocking agents, including nifedipine, nisoldipine, diltiazem, verapamil, CoCl2 and MnCl2. Results Five micromolar Nifedipine, 1 similar to mu M nisoldipine, 10 similar to mu M diltiazem, 5 similar to mu M verapamil, 3 similar to mM CoCl2 and 5 similar to mM MnCl2 evoked uniformly a 9095% blockade of Ca2+ current in the absence of isoproterenol. Isoproterenol (100 similar to nM) alone increased the amplitude of Ca2+ current from 6.8 similar to +/-similar to 1.3 to 23.7 similar to +/-similar to 2.2 pA/pF in a reversible manner. Isoproterenol caused a marked enhancement of Ca2+ current even in the presence of nifedipine, nisoldipine, diltiazem and verapamil, but not in the presence of CoCl2 or MnCl2. Conclusion The results indicate that the action of isoproterenol is different in the presence of organic and inorganic Ca2+ channel blockers. CoCl2 and MnCl2 were able to fully prevent the effect of isoproterenol on Ca2+ current, while the organic Ca2+ channel blockers failed to do so. This has to be born in mind when the effects of organic Ca2+ channel blockers are evaluated either experimentally or clinically under conditions of increased sympathetic tone.

引用

页码：42 / 50

页数：9

共 39 条

[1] Endocardial versus epicardial differences in L-type calcium current in canine ventricular myocytes studied by action potential voltage clamp [J].