Acute effect of thymoquinone on action potential and ionic currents of rat cardiac myocytes. - GreenMedInfo Summary
Acute effect of thymoquinone on action potential and ionic currents of rat cardiac myocytes.
Bratisl Lek Listy. 2021 ;122(6):424-431. PMID: 34002617
OBJECTIVES: This study aims to investigate the acute effects of thymoquinone (TQ) which has been suggested to be a cardioprotective agent, on ventricular myocytes.
METHODS: Freshly isolated rat ventricular myocytes were exposed to TQ and using standard whole-cell patch-clamp technique action potential (AP), sodium current (INa), L-type calcium current (ICaL) and transient outward potassium current (Ito) were measured.
RESULTS: TQ prolonged the duration of AP and decreased the peak value compared to that of control myocytes. Consistently, it inhibited INa in a concentration-dependent manner and shifted the channel kinetics to more hyperpolarized voltages. Besides, TQ not only inhibited Ito and ICaL but also significantly attenuated the isoproterenol-induced increase in ICaL.
CONCLUSION: The effect of TQ on cardiomyocytes has been demonstrated for the first time. TQ changes AP morphology along with ionic currents and alleviatesβ-adrenergic response in adult ventricular myocytes. These results indicate that TQ may be considered as a therapeutic agent in cases such as diabetic cardiomyopathy and cardiac hypertrophy, wherein the β-adrenergic system is over-activated (Tab. 2, Fig. 6, Ref. 30).