Effects Of Anandamide On Electrophysiological Properties In Isolated Rat Ventricular Myocytes

This study aimed to investigate the effects of anandamide, a kind of endocannabinoids, on electrophysiological properties of rat ventricular myocytes. Method Whole-cell patch-clamp technique was used to record Action Potential (AP), calcium-independently transient outward potassium current (Ito), delay rectifier potassium current (IK) and inward rectifier potassium current (IK1) before and after anandamide perfusion at different concentrations. Results (1)Anandamide(10-9M)can significantly decrease Action Potential Duration (APD50 and APD90),while it has no effects on Resting Membrane Potential(RMP) and Action Potential Amplitude(APA). (2) Anandamide (10-9-10-5M) has dual effects on Ito. Anandamide(10-5M) can decrease Ito by 20.2±3.6%, from 22.5±1.3pA/pF to 17.9±1.8pA/pF , p<0.05, n=8; while in lower concentration(10-9M), it can increase Ito by 25.8±2.6%, from 20.6±1.2 pA/pF to 25.9±1.6pA/pF, p<0.05, n=8. (3) Anandamide (10-9and 10-5M) has no effects on IK and IK1. Conclusion Anandamide(10-9M) can significantly decrease Action Potential Duration(APD50 and APD90); anandamide(10-9 to10-5M) has dual effects on Ito, while it has no effects on IK and IK1.