Venodilator effects of pranidipine, a 1,4-dihydropyridine Ca2+ channel antagonist, in rats: comparison with nifedipine and amlodipine.
The effects of pranidipine, a dihydropyridine Ca2+ channel antagonist, on mean circulatory filling pressure, an index of body venous tone, were compared with those of other dihydropyridines (nifedipine and amlodipine) and nitroglycerin in anaesthetized hexamethonium- and norepinephrine-treated rats. In this study, the compounds were used at doses having a equi-hypotensive effect. Intravenous bolus injection of pranidipine (10 and 30 microg/kg) significantly decreased mean circulatory filling pressure in a dose-dependent manner, as did nitroglycerin (30 and 100 microg/kg). Nifedipine (30 and 100 microg/kg), however, did not affect mean circulatory filling pressure. Amlodipine (1000 and 3000 microg/kg) decreased mean circulatory filling pressure only at the higher dose. These results suggest that pranidipine has a greater venodilator effect than nifedipine and amlodipine.
Hirano
T
T
2nd Tokushima Institute of New Drug Research, Otsuka Pharmaceutical Co., Ltd., Kawauchi-cho, Japan.
Ohura
M
M
Orito
K
K
Fujiki
H
H
Miyakoda
G
G
Mori
T
T
D017311:Amlodipine / Q000494:pharmacology*; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004095:Dihydropyridines / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D009543:Nifedipine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014690:Venous Pressure / Q000187:drug effects*
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D017311:Amlodipine; C038806:1,4-dihydropyridine; C048161:pranidipine; D009543:Nifedipine