[Effects of sodium molybdate on guinea pig atria contractility].
Sodium molybdate (Mo) 10-1000 mumol/L markedly reduced the contratile force of left atria isolated from guinea pig. Mo 100 mumol/L obviously reduced the heart rates in right atria, markedly prolonged the functional refractory period from 185 +/- 12 to 245 +/- 4 ms and inhibited the resting potentiation. Mo 100 and 300 mumol/L reduced the frequency-dependent positive staircase phenomenon. However, verapamil 25 mumol/L reversed the frequency-dependent positive staircase phenomenon to negative one. The mechanism can be explained by the effect on Ca2+ movement in the heart atrium.
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Research Laboratory of Electrophysiology, Xi-an Medical University, China.
Li
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D000818:Animals; D005260:Female; D006168:Guinea Pigs; D006325:Heart Atria; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008982:Molybdenum / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects*; D012032:Refractory Period, Electrophysiological / Q000187:drug effects
D008982:Molybdenum; C024687:sodium molybdate(VI)