Effects of calcium channel blockers on nicotinic acetylcholine receptor current in rat chromaffin cells / 中国病理生理杂志

ABSTRACT

AIM: To study the effects of calcium channel blockers (CCB) on nicotinic acetylcholine receptor current (I_(NIC)) in rat adrenal medullar chromaffin cells (RAMCs). METHODS: By using the whole-cell clamp-patch technique, we have investigated the effects of nifedipine(NIF)、?-conotoxin GVIA and ?-agatoxin IVA on I_(NIC) induced by nicotine(NIC) before and after RAMCs perfusion. RESULTS: After perfusing RAMCs for 5 min, different kinds of calcium channel blockers at different concentration showed significant inhibitory effects on I_(NIC) induced by 50 ?mol/L NIC. The peak inhibition rates of 10 ?mol/L NIF、400 nmol/L ?-conotoxin GVIA and 100 nmol/L ?-agatoxin IVA were (61.7?5.1)%,(29.3?7.4)% and (17.6?7.5)%, respectively. CONCLUSION: The acute effects of different kinds of CCBs on RAMC were that they obviously inhibited I_(NIC) induced by NIC. These results suggest that CCBs may inhibit catecholamine secretion by directly blocking nicotinic acetylcholine receptor channel. [