Effects of molybdenum, silicon and nickel on alpha1-adrenoceptor-induced constriction of rat isolated aorta.
1. To determine the effects of trace elements on alpha1-adrenoceptor-mediated vasoconstriction, we studied the effects of molybdenum (Mo), silicon (Si) and nickel (Ni) on vasoconstrictor response to an alpha1-adrenoceptor agonist in rat aorta. 2. Cumulative concentration-contraction curves were obtained for phenylephrine (1 nmol/L-10 micromol/L) in the absence and presence of Mo, Si and Ni (0.3, 1 and 3 micromol/L) in rat aorta rings. Increasing the concentration of Mo and Si from 0.3 to 3 micromol/L shifted the cumulative concentration-contraction curve to the right, but did not reduce the maximal contractile response to phenylephrine. In contrast, Ni at 1 and 3 micromol/L shifted the cumulative concentration-contraction curve to the right and, at 3 micromol/L, reduced the maximum contractile response to phenylephrine. 3. We conclude that micromolar concentrations of Mo, Si and Ni affected alpha1-adrenoceptor-induced vasoconstriction and that Ni significantly inhibited the maximal contractile response to phenylephrine in rat isolated aorta.
Liu
Dong Ling
DL
Cardiac Research Laboratory, National Heart Centre of Singapore, Singapore.
Yan
Ming
M
Chua
Yeow Leng
YL
Chen
Chen
C
Lim
Yean Leng
YL
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D008982:Molybdenum / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D009532:Nickel / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects*; D012825:Silicon / Q000494:pharmacology*
D018340:Receptors, Adrenergic, alpha-1; D009532:Nickel; D008982:Molybdenum; D012825:Silicon