1.
Gen Physiol Biophys
; 7(1): 39-49, 1988 Feb.
Artigo
em Inglês
| MEDLINE
| ID: mdl-2456250
RESUMO
The effects of ryanodine on negative force staircase and potentiated rested-state contraction (RC) in rat myocardium were compared to the action of Ca release stimulator (caffeine) and inhibitors (local anesthetics). Only low ryanodine concentrations (0.1-0.5 mumol/l) were found to reverse anomalous mechanical patterns in rat myocardium to similar to those as generally observed in other mammalian species. Ryanodine-induced positive staircase and a weak RC were potentiated by noradrenaline. The results obtained seem to characterize ryanodine as a Ca2+ release stimulator rather than an inhibitor in this species and suggest different molecular substrates for ryanodine and caffeine inotropy in rat myocardium.