Journal of Jilin University Medicine Edition ›› 2017, Vol. 43 ›› Issue (01): 6-10.doi: 10.13481/j.1671-587x.20170102

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Influence of ADMA in electrical activity of pacemaker cells in guinea-pig left ventricular outflow tract

ZHAO Lanping1, XUE Shufang1, CHEN Yanjing2, WANG Xuefang1, CHEN Lifeng1, HUANG Jiacheng1   

  1. 1. Department of Physiology, Hebei North University, Zhangjiakou 075000, China;
    2. Institute of Basic Theories of TCM, China Academy of Chinese Medical Sciences, Beijing 100700, China
  • Received:2016-04-27 Online:2017-01-28 Published:2017-02-08

Abstract:

Objective: To study the influence of endogenous nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) in the electrical activity of pacemaker cells in the guinea-pig left ventricular outflow tract,and to explore the effect of ADMA on the occurrence and development of ventricular outflow tract arrhythmias.Methods: The isolated guinea-pig left ventricular outflow tract tissue was perfused with fully oxygenated Locke solution under constant temperature and constant flow velocity.The spontaneous slow action potentials(sAP) of guinea-pig left ventricular tract were recorded by conventional intracellular microelectrode technique.The effects of NOS inhibitor ADMA(1,10 and 100 μmol·L-1) on the spontaneous sAP were studied.And the effects of ADMA under the condition of pretreatment of sodium nitroprusside(SNP) were also explored(control group,10 μmol·L-1 SNP group,and SNP+ADMA group).Results: Compared with control group,the different indexes of sAP in 1 μmol·L-1 ADMA group had no significant changes(P>0.05).Compared with control group, the velocity of diastolic depolarization (VDD),the rate of pacemaker firing (RPF) and the maximal rate of depolarization(Vmax) in 10 and 100 μmol·L-1 ADMA groups were siginificantly decreased(P<0.05),and the 50% and 90% of duration of action potential(APD50 and APD90) were markedly increased(P<0.05). Compared with 1 μmol·L-1ADMA group,the RPF in 10 μmol·L-1 ADMA group was siginificantly decreased(P<0.05) and the APD90 was markedly increased(P<0.05); compared with 1 μmol·L-1ADMA group,the RPE,Vmax,and APD50 had significant changes (P<0.05).Compared with 10 μmol·L-1ADMA group,the APA in 100 μmol·L-1ADMA group was significantly decreased (P<0.05). After pretreatment of 10 μmol·L-1 SNP for 10 min,followed by 10 μmol·L-1 SNP and 10 μmol·L-1 ADMA,the inhibitory effects of spontaneous activity induced by ADMA could be reversed;compared with control group,the VDD and RPF were significantly increased (P<0.05),the Vmax and APA had no significant changes(P>0.05), and the APD90 was markedly decreased (P<0.05).Conclusion: Endogenous NOS inhibitor ADMA can decrease the spontaneous activity of left ventricular outflow tract,and the inhibitory effects induced by ADMA can be reversed under the condition of pretreatment of NO donor SNP.

Key words: left ventricular outflow tract, spontaneous slow action potentials, asymmetric dimethylarginine

CLC Number: 

  • Q463