Calcium channel blocker-like action of 1,9-dideoxyforskolin in vascular smooth muscle.
The inhibitory effect of 1,9-dideoxyforskolin (DFK) on the contraction of rat aorta was compared with that of forskolin. DFK inhibited the contraction induced by high K+ more strongly than that induced by norepinephrine, whereas forskolin more strongly inhibited the norepinephrine-induced contraction. The inhibitory effect of DFK on high K(+)-induced contraction was antagonized by an increase in extracellular Ca2+ concentration. DFK inhibited the increase in cytosolic Ca2+ level and contraction in parallel whereas forskolin inhibited the contraction more strongly than the cytosolic Ca2+ level. These results suggest that DFK, but not forskolin, inhibits vascular smooth muscle contraction by a Ca2+ channel blocker-like action.
Abe
A
A
Department of Veterinary Pharmacology, Faculty of Agriculture, University of Tokyo, Japan.
Karaki
H
H
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D005576:Colforsin / Q000031:analogs & derivatives* / Q000494:pharmacology; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D016257:Fura-2; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology; D011188:Potassium / Q000037:antagonists & inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D002121:Calcium Channel Blockers; D005576:Colforsin; C047983:1,9-dideoxyforskolin; D011188:Potassium; D002118:Calcium; D016257:Fura-2; D009638:Norepinephrine