Effects of manganese on 45Ca mobilization and contractile responses in rabbit aortic smooth muscle.
In rabbit aortic smooth muscle, 1.5 mM Mn2+ inhibits contractile responses to norepinephrine more than those to high K+. Other associated effects include decreases in the La3+-resistant high affinity Ca2+ fraction, the high affinity Ca2+ uptake component in the Scatchard-coordinate plot, and high affinity Ca2+ uptake and binding in canine aortic microsomes. Higher (15 mM) concentrations of Mn2+ are less selective. Thus, those Ca2+ mobilization components and contractile responses associated with high affinity bound Ca2+ are more sensitive to inhibition by Mn2+.
D000818:Animals; D001667:Binding, Competitive; D002118:Calcium / Q000378:metabolism*; D002132:Calcium Radioisotopes; D005260:Female; D066298:In Vitro Techniques; D007700:Kinetics; D007811:Lanthanum / Q000494:pharmacology; D008297:Male; D008345:Manganese / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits; D013997:Time Factors
D002132:Calcium Radioisotopes; D008345:Manganese; D007811:Lanthanum; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine