- 作者: Denis V Abramochkin; Nail N Haertdinov; Maria V Porokhnya; Andrew L Zefirov; Gusel F Sitdikova
- 作者服務機構: Department of Human and Animal Physiology, Moscow State University, Moscow, Russia
- 中文摘要: --
- 英文摘要:
Background: Carbon monoxide (CO) is a toxic gas, which also acts in the organism as a
neurotransmitter. It is generated as a by-product of heme breakdown catalyzed by
heme oxygenase. We have investigated changes in electrical and contractile activity
of isolated rat atrial and ventricular myocardium preparations under the influence of
CO.
Methods: Standard microelectrode technique was used for intracellular registration of electrical
activity in isolated preparations of atrial and ventricular myocardium. Contractions of
atrial myocardial stripes were registered via force transducer.
Results: CO (10-4 - 10-3 M) caused prominent decrease of action potential duration (APD) in
working atrial myocardium as well as significant acceleration of sinus rhythm. In
addition CO reduced force of contractions and other parameters of contractile activity.
Inhibitor of heme oxygenase zinc protoporphyrin IX exerts opposite effects:
prolongation of action potential, reduction of sinus rhythm rate and enhancement of
contractile function. Therefore, endogenous CO, which may be generated in the heart
due to the presence of active heme oxygenase, is likely to exert the same effects as
exogenous CO applied to the perfusing medium. In ventricular myocardium
preparations exogenous CO also induced shortening of action potential, while zinc
protoporphyrin IX produced the opposite effect.
Conclusions: Thus, endogenous or exogenous carbon monoxide may act as an important regulator
of electrical and contractile cardiac activity. - 中文關鍵字: --
- 英文關鍵字: --