Modulation of L-type calcium current in rat cardiac myocytes by sulfur dioxide derivatives.
The effects of sulfur dioxide (SO(2)) derivatives (bisulfite and sulfite, 1:3M/M) on voltage-dependent L-type calcium current (I(Ca,L)) in isolated rat ventricular myocytes were studied using the whole cell patch-clamp technique. SO(2) derivatives increased I(Ca,L) in a concentration-dependent manner. SO(2) derivatives shifted both the steady-state activation and the inactivation curves of I(Ca,L) to more positive potentials, the effect on the latter being more pronounced. SO(2) derivatives markedly accelerated the recovery of I(Ca,L) from inactivation. SO(2) derivatives also significantly shortened the fast and slow time constants of inactivation. These results suggested that SO(2) inhalation might cause cardiac myocyte injury through increasing intracellular calcium via voltage-gated calcium channels.
Nie
Aifang
A
Institute of Environmental Medicine and Toxicology, Shanxi University, Taiyuan, China.
Meng
Ziqiang
Z
D000393:Air Pollutants / Q000494:pharmacology* / Q000633:toxicity; D000818:Animals; D020746:Calcium Channels, L-Type / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D008564:Membrane Potentials / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D013458:Sulfur Dioxide / Q000494:pharmacology* / Q000633:toxicity
D000393:Air Pollutants; D020746:Calcium Channels, L-Type; D013458:Sulfur Dioxide