Effects of pincainide on contractile responses and 45Ca movements in rat isolated vascular smooth muscle.
The effects of pincainide, a new beta-amino anilide, on contractile responses and 45Ca fluxes were studied in rat aorta and on spontaneous mechanical activity in rat portal veins. Pincainide (10(-5) to 10(-2) M) produced a dose-dependent inhibition of noradrenaline (NA) and high K+ -induced contractions. These inhibitory effects were observed with pincainide added either before or after the induced contractions. The Ca2+ -induced contractions of K+ -depolarized aorta as well as the spontaneous mechanical activity of portal veins were also inhibited by pincainide. Pincainide (5 X 10(-3) M) inhibited the 45Ca influx stimulated by 10(-6) M NA and increased 45Ca efflux. It was concluded that in isolated rat aorta, pincainide not only inhibited the influx of Ca2+ reducing the contractile responses to NA and high K+ but it also inhibited other effects related to NA-induced release of intracellular Ca2+ stores.
D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D001381:Azepines / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002132:Calcium Radioisotopes; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014661:Vasoconstriction / Q000187:drug effects*
D000779:Anesthetics, Local; D001381:Azepines; D002132:Calcium Radioisotopes; C040465:pincainide; D008012:Lidocaine; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine