Effects of micromolar concentrations of Mn, Mo, and Si on alpha1-adrenoceptor-mediated contraction in porcine coronary artery.
We studied the effects of trace elements, Mn, Mo, and Si, on vasoconstriction induced by norepinephrine (NE) or electrical field stimulation in isolated porcine right coronary arteries. Alpha1-adrenoceptor (AR) antagonist prazosin dose-despondently suppressed vasoconstriction in response to NE or field stimulation indicating an alpha1-AR mediated response. Mn, Mo, and Si at 0.3-3 micromol/L dose-despondently inhibited NE mediated contraction (all p < 0.05). In contrast, Mn, Mo, and Si at the same concentrations (0.3-3 micromol/L) enhanced the maximal contractile response to field stimulation in a dose-dependent manner (all p < 0.05), but these elements at 10 micromol/L suppressed the vasoconstrictive response. The results indicate that in porcine right coronary arteries, the alpha1-AR-mediated vasoconstriction by NE or electrical field stimulation was affected differently by micromolar concentrations of Mn, Mo, and Si and that the elements might facilitate NE release presynaptically but inhibit the contractile response postsynaptically.
Yan
M
M
Institution of Vascular Medicine, The Third Hospital, Beijing Medical University, P.R. China.
Lu
Z
Z
Du
X J
XJ
Han
C
C
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000502:physiology; D003331:Coronary Vessels / Q000187:drug effects* / Q000502:physiology; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D008345:Manganese / Q000494:pharmacology*; D008982:Molybdenum / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology*; D012825:Silicon / Q000494:pharmacology*; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D000317:Adrenergic alpha-Antagonists; D018340:Receptors, Adrenergic, alpha-1; D008345:Manganese; D008982:Molybdenum; D009638:Norepinephrine; D011224:Prazosin; D012825:Silicon