Cromakalim, a vasodilator, differentially inhibits Ca2+ currents in NG108-15 neuroblastoma x glioma hybrid cells.
Extracellular perfusion with the antihypertensive agent cromakalim produced an inhibition of 22-66% in the low-threshold transient Ca2+ (T-like) current in NG108-15 hybrid cells. Cromakalim suppressed the high-threshold and long-lasting Ba2+ current (L-like Ca2+ current) by 29-73%, but had almost no effect on the high-threshold and inactivating Ba2+ current (N-like Ca2+ current). IC50 for T-like and L-like currents was the same at about 100 microM. The inhibitory effect developed relatively fast and was reversible. These results indicate that cromakalim can selectively inhibit the activity of inward Ca2+ currents.
Ito
Y
Y
Department of Biophysics, Kanazawa University School of Medicine, Japan.
Miyamori
I
I
Matsubara
T
T
Takeda
R
R
Higashida
H
H
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001578:Benzopyrans / Q000494:pharmacology*; D001692:Biological Transport; D002118:Calcium / Q000037:antagonists & inhibitors*; D019806:Cromakalim; D005910:Glioma / Q000378:metabolism*; D006822:Hybrid Cells; D008564:Membrane Potentials; D051379:Mice; D009447:Neuroblastoma / Q000378:metabolism*; D010276:Parasympatholytics / Q000494:pharmacology*; D011758:Pyrroles / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014665:Vasodilator Agents / Q000494:pharmacology*
D000959:Antihypertensive Agents; D001578:Benzopyrans; D010276:Parasympatholytics; D011758:Pyrroles; D014665:Vasodilator Agents; D019806:Cromakalim; D002118:Calcium