Negative Inotropic Effects of Caffeine Related to Leak of Ca2+ from the Sarcoplasmic Reticulum
Part of the
Advances in Experimental Medicine and Biology
book series (AEMB, volume 311)
Caffeine has been reported to have either a positive or a negative inotropic effect on cardiac muscle, and it is not known what circumstances are necessary for each of these effects. In this study, rat atria were exposed to caffeine (1–5) mM with regular stimulation at 0.1 – 3 Hz. Postrest contractions were also observed to determine if inhibition of contractions was always seen when stimulation was interrupted (Endoh and Iijima, 1981). As expected, addition of caffeine to the superfusate resulted in a transient positive inotropic response, when stimulation was 0.5 or 2.0 Hz. In contrast with this, when stimulation was 0.1 Hz, there was only a negative inotropic response. This decrease in developed tension was greater with 1 mM than with 5 mM caffeine, (see Table 1).
KeywordsSarcoplasmic Reticulum Stimulation Frequency Negative Inotropic Effect Inotropic Response Develop Tension
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Endoh, M. and Iijima, T. 1981. Twitch potentiation by rest in canine ventricular muscle: effects of theophylline. Am.J.Physiol.
Lewartowski, B. and Zdanowski, K. 1990. Net Ca2+
influx and sarcoplasmic reticulum Ca2+
uptake in resting single myocytes of the rat heart: comparison with guinea-pig. J.Mol.Cell.Cardiol.
Schouten, V.J.A., van Deen, J.K., de Tombe, P. and Verveen, A.A. 1987. Force-interval relationship in heart muscle of mammals: a calcium compartment model. Biophys.J.
Shattock, M.J. and Bers, D.M. 1989. Rat vs. rabbit ventricle: Ca flux and intracellular Na assessed by ion-selective microelectrodes. Am.J.Physiol.
© Springer Science+Business Media New York 1992