Hydrogen peroxide modulates whole cell Ca2+ currents through L-type channels in cultured rat dentate granule cells.
Modification of voltage-gated Ca(2+) channels by hydrogen peroxide, a membrane-permeable form of reactive oxygen species, in cultured dentate granule cells was examined using the whole cell patch clamp technique. Pretreatment with hydrogen peroxide (1 and 10 microM) for 2 h enhanced the Ca(2+) current without affecting its voltage dependence. The enhancement was completely cancelled by 1 mM glutathione, an antioxidant, and 2 microM nifedipine, an L-type Ca(2+) channel blocker. In contrast, the enhancement of the Ca(2+) current was not mimicked by pretreatment with 10 microg/ml tunicamycin, an endoplasmic reticulum stressor. These results suggest that oxidative stress induced by hydrogen peroxide selectively regulates the activity of L-type Ca(2+) channels.
Akaishi
Tatsuhiro
T
Department of Pharmacology, College of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan.
Nakazawa
Ken
K
Sato
Kaoru
K
Saito
Hiroshi
H
Ohno
Yasuo
Y
Ito
Yoshihisa
Y
D000818:Animals; D020746:Calcium Channels, L-Type / Q000502:physiology*; D002478:Cells, Cultured; D018891:Dentate Gyrus / Q000187:drug effects* / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D020746:Calcium Channels, L-Type; D006861:Hydrogen Peroxide