@article{APS5274,
author = {Dai-yuan WANG and Hong-zhan WANG and Cheng-ming ZHOU and Ke-jin ZHANG},
title = {Effects of nicotinamide on action potentials of sinoatrial node cell and depolarized papillary muscle cell of guinea pig},
journal = {Acta Pharmacologica Sinica},
volume = {7},
number = {5},
year = {2016},
keywords = {},
abstract = {The effects of nicotinamide (Nic) on action potentials (AP) of guinea pig SA node cell, normal papillary muscle cell and papillary muscle cell depolarized by high K+ were studied. Nic 33 mmol/L increased the slope of phase 4 of AP of SA node cell by 43%; APD90 of normal papillary muscle cell was shortened by 10%; Vmaxs of phase 0 of AP of depolarized papillary muscle cell was not much changed; Vmaxf of phase 0 of AP of depolarized papillary muscle cell was decreased by 21%; excitability of the depolarized papillary muscle was inhibited. Verapamil 0.22 micromol/L decreased the slope of phase 4 and Vmax of AP of SA node cell respectively by 44% and 80%; Vmaxs of AP of the depolarized papillary muscle cell was decreased by 23%; Vmaxf was not significantly changed.
The results suggest: 1) There may be a difference between Isi in the phase 4 of SA node AP and Isi in the phase 0 of SA mode AP and Vmaxs of AP of the partially depolarized papillary muscle cell; 2) The inhibition of Nic on excitability of myocardium may be related to the effect on Na+ channel.},
issn = {1745-7254}, url = {http://www.chinaphar.com/article/view/5274}
}