Activating protein kinase C enhances ventricular action potential duration restitution and increase arrhythmia susceptibility in Langendorff-perfused rabbit hearts
10.3760/cma.j.issn.0253-3758.2012.09.013
- VernacularTitle:激活蛋白激酶C对离体兔心室电整复性及心律失常的影响
- Author:
Tao LIU
1
;
Mu QIN
;
He HU
;
He HUANG
;
Cong-Xin HUANG
Author Information
1. 武汉大学
- Keywords:
Electrophysiology;
Protein kinase C;
Action potentials;
Arrhythmia
- From:
Chinese Journal of Cardiology
2012;40(9):780-785
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine effects of activating protein kinase C (PKC) on ventricular action potential duration restitution (APDR) and Burst stimulus induced arrhythmia in Langendorff-perfused rabbit hearts.Methods Male rabbits were equally divided into three groups randomly: control group (Tyrode's solution perfusion),PKC agonist phorbol-12-myristate-13- acetate (PMA,100 nmol/L) group and PKC inhibitor bisindolylmaleimide (BIM,500 nmol/L) group.Thirty minutes after perfusion,the monophasic action potential (MAP) and effective refractory period (ERP) were determined in right basal ventricle (RB),right apex ( RA ),left basal ventricle (LB) and left apex (LA) of all the animals,and APDR curve was drawn.Burst stimulus method was used to induce ventricular arrhythmia in perfused rabbit hearts; Real-time PCR was used to detect the mRNA expression of PKC in four different areas of ventricle.Results Compared with the control group,the ERP,90％ of monophasic action potential duration ( MAPD90 ) and ERP/MAPD90 were significantly shortened ( all P ＜ 0.01 ),the max slopes ( Smax ) of APDR curve were significantly steeper (RB:1.22 ±0.23 vs.0.65 ± 0.19 ; RA:2.99 ± 0.29 vs.1.02 ± 0.18 ;LB:1.84 ±0.21 vs.0.85 ±0.12; LA:4.02 ±0.32 vs.1.12 ±0.23,all P ＜0.01 ) and the incidences of ventricular arrhythmia were significantly increased in the PMA group.All parameters were similar between the BIM group and the control group (all P ＞ 0.05).Conclusion Activating PKC could enhance the max slopes of APDR curve at various ventricular areas and subsequently increase arrhythmia susceptibility in Langendorff-perfused rabbit hearts.
