Dibutyryl cyclic AMP and forskolin inhibit phosphatidylinositol hydrolysis, Ca2+ influx and contraction in vascular smooth muscle.
Dibutyryl cyclic AMP and forskolin inhibited the contraction induced by norepinephrine (NE) more strongly than the high K(+)-induced contraction in isolated rat aorta. These inhibitors inhibited the 45Ca2+ influx stimulated by NE but not that by high K+, and they inhibited NE-induced inositol monophosphate accumulation. These results suggest that cAMP inhibits NE-induced contraction, at least partly, by inhibiting the alpha-adrenoceptor-mediated signal transduction and high K(+)-induced contraction by decreasing Ca2+ sensitivity but not Ca2+ influx.
Ahn
H Y
HY
Department of Pharmacology, College of Medicine, Chungbuk National University, Cheongju, Korea.
Kang
S E
SE
Chang
K C
KC
Karaki
H
H
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects
D010716:Phosphatidylinositols; D011942:Receptors, Adrenergic, alpha; D005576:Colforsin; D003994:Bucladesine; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine