The effects of nickel on contraction and membrane current in isolated rat myocytes.
Depolarization of isolated myocytes for several seconds produces a maintained, tonic component of tension. We have found that this is abolished by 5 mM-Ni2+. Furthermore if Ni2+ is applied after the tonic contraction has developed then its relaxation is prevented. These results are consistent with the hypothesis that Ni2+ inhibits Na+-Ca2+ exchange. Finally, also consistent with an inhibition of Na+-Ca2+ exchange, Ni2+ abolishes the transient inward current while having no effect on the underlying change of [Ca2+]i.
O'Neill
S C
SC
Department of Physiology, University College London.
Valdeolmillos
M
M
Eisner
D A
DA
D000818:Animals; D002118:Calcium / Q000378:metabolism; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D007474:Ion Exchange; D008564:Membrane Potentials / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism; D009532:Nickel / Q000494:pharmacology*; D051381:Rats; D012964:Sodium / Q000378:metabolism
D009532:Nickel; D012964:Sodium; D002118:Calcium