Protection by oral pretreatment with taurine against the negative inotropic effects of low-calcium medium on isolated perfused chick heart

Abstract

Chicks were given taurine by mouth using a cannula pushed down into the oesophagus. This treatment had protected the heart, when subsequently removed, against the decline of contractile force in the perfused heart brought about by low-calcium media. A small but statistically significant increase in taurine concentration occurred in the ventricular tissue of such pretreated hearts. In contrast, pretreatment with taurine did not affect ventricular calcium level. Addition of taurine (3 to 100 mmol·litre⁻¹) into the perfusing solution did not alter the cyclic AMP level in the control perfused hearts, and failed to induce slow channel action potentials in hearts whose fast Na⁺ channels had been inactivated by high K⁺ (25 mmol·litre⁻¹). However, taurine perfusion produced a significant positive inotropic action which became stable after 5 to 10 min of exposure.