Effects of felodipine on vascular smooth muscle in comparison with nifedipine.
Felodipine (ethylmethyl 4-(2,3-dichlorophenyl)-1,4-dihydro-2,6-dimethyl- 3,5-pyridine dicarboxylate, CAS 72509-76-3), a vasoselective calcium antagonist, has a slow onset inhibitory effect on high K(+)-induced contractions in vascular smooth muscle and a longer duration than that of nifedipine. In addition it non-competitively inhibits Ca(++)-induced contraction in the depolarized aorta or femoral artery in the rat. Felodipine's inhibitory effect on caffeine or norepinephrine-induced contraction was observed at a micromolar range. This result suggests that felodipine may inhibity Ca++ release from intracellular Ca++ stores through a mechanism of Ca++ or inositol 1,4,5-triphosphate induced Ca++ release in addition to a blockade of Ca++ influx through the sarcolemma.
Kuroda
K
K
Pre-clinical Research Department, Ciba-Geigy Limited, Takarazuka,Japan.
Fukuda
Y
Y
Nakao
K
K
Inukai
T
T
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D015736:Felodipine / Q000494:pharmacology*; D005263:Femoral Artery / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D011921:Rats, Inbred WKY; D012508:Sarcolemma / Q000187:drug effects / Q000378:metabolism
D002110:Caffeine; D009543:Nifedipine; D015736:Felodipine; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine