Activation of δ-opioid receptors inhibits L-type Ca(2+) current and transient outward K(+) current in rat ventricular myocytes.
- Author:
Yuan-Yuan LIN
1
;
Dong-Mei WU
;
Lei LIU
;
Qing-Hua LIU
;
Zhe-Yi YAN
;
Bo-Wei WU
Author Information
1. Department of Physiology, Shanxi Medical University, Taiyuan 030001, China.
- Publication Type:Journal Article
- MeSH:
Animals;
Anti-Arrhythmia Agents;
Benzamides;
pharmacology;
Calcium Channels, L-Type;
metabolism;
Cells, Cultured;
Heart Ventricles;
cytology;
Myocytes, Cardiac;
drug effects;
metabolism;
Naltrexone;
analogs & derivatives;
pharmacology;
Patch-Clamp Techniques;
Piperazines;
pharmacology;
Potassium Channels;
metabolism;
Rats;
Receptors, Opioid, delta;
agonists
- From:
Acta Physiologica Sinica
2008;60(1):38-42
- CountryChina
- Language:English
-
Abstract:
In the present study, whole-cell patch-clamp technique was used to observe the effects of SNC162, a selective agonist of δ-opioid receptors, on L-type Ca(2+) current (I(Ca-L)) and transient outward K(+) current (I(to)) in rat ventricular myocytes. The results showed that SNC162 significantly inhibited I(Ca-L) and I(to) in rat ventricular myocytes. The maximal inhibition rate of I(Ca-L) and I(to) reached (46.13±4.12)% and (36.53±10.57)%, respectively. SNC162 at 1×10(-4) mol/L inhibited the current density of I(Ca-L) from (8.98±0.40) pA/pF to (4.84±0.44) pA/pF (P<0.01, n=5) and inhibited that of I(to) from (18.69±2.42) pA/pF to (11.73±1.67) pA/pF (P<0.01, n=5). Furthermore, the effects of naltrindole, a highly selective antagonist of δ-opioid receptors, on I(Ca-L) and I(to) were also observed. The results showed that naltrindole alone had no effects on I(Ca-L) and I(to), while it abolished the inhibitory effects of SNC162 on I(Ca-L) and I(to). In conclusion, SNC162 concentration-dependently inhibited I(Ca-L) and I(to) in rat ventricular myocytes via activation of the δ-opioid receptors, which may be a fundamental mechanism underlying the antiarrhythmic effect of activating δ-opioid receptors.
