Okoshi, M. P.Ferreira Tucci, P. J.Okoshi, K.Padovani, C. R.Cicogna, A. C.2014-05-272014-05-271995-11-01Arquivos brasileiros de cardiologia, v. 65, n. 5, p. 417-421, 1995.0066-782Xhttp://hdl.handle.net/11449/64647PURPOSE: To evaluate the effects of afterload on peak rate of tension rise (dT/dt) in the isolated muscle. METHODS: Left ventricular papillary muscles from Wistar rats were studied in isometric and isotonic afterloaded contractions. Muscles were analised in Krebs-Henseleit solution with calcium concentration of 2.52mM at 28 degrees C. The resting muscle length (preload) was maintained constant. The peak isometric developed tension (DT) and dT/dt were measured during increases of afterload (25, 50, 75 and 100% from DT). RESULTS: A rise in afterload corresponding to 50, 75 and 100% of DT, did not cause an increase in dT/dt values (p > 0.05). The dT/dt value decreased (p < 0.05) when afterload was changed from 75% to 25% of DT. CONCLUSION: The data suggest that an increase in the afterload from 50% of the DT did not promote changes in the dT/dt.417-421poranimalheart contractionheart outputheart papillary musclemalemuscle isometric contractionphysiologyratWistar ratAnimalsCardiac OutputIsometric ContractionMaleMyocardial ContractionPapillary MusclesRatsRats, WistarInfluência da pós-carga sobre a taxa de variação da tensão desenvolvida (dT/dt). Estudo em músculo cardíaco isolado.Influence of afterload on the rate of variation of developed pressure (dT/dt). Study in isolated cardiac muscleArtigoAcesso aberto2-s2.0-00294025602-s2.0-0029402560.pdf8727897080522289