Effects of Bay K 8644 on the electrically evoked and KCl-evoked norepinephrine release and the corresponding contraction in isolated canine saphenous veins.
Bay K 8644 caused no significant effects on the 3H overflow and contraction evoked by electrical stimulation in the canine saphenous vein preloaded with [3H]norepinephrine. Bay K 8644 significantly enhanced the 3H overflow evoked by 40 mM KCl in a concentration-dependent manner, which was antagonized by nisoldipine. Bay K 8644 failed to significantly augment the KCl-evoked contraction. These results suggest that there is a difference between the modes of action of Bay K 8644 on norepinephrine releases evoked by electrical stimulation and KCl.
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D000818:Animals; D004285:Dogs; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects*; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009543:Nifedipine / Q000031:analogs & derivatives / Q000494:pharmacology; D015737:Nisoldipine; D009638:Norepinephrine / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D012501:Saphenous Vein / Q000187:drug effects
D007473:Ion Channels; D015737:Nisoldipine; D011189:Potassium Chloride; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D009543:Nifedipine; D009638:Norepinephrine