Taurine and myocardial noradrenaline

Taurine (CAS 107-35-17) is an anticonvulsant used also as an adjunct in the treatment of cardiovascular disorders. Therefore, we studied its effects noradrenergic transmission in the isolated rabbit heart prelabelled with 3H-noradrenaline. At the concentrations of 1 and 10 mmol/l taurine treatment was without effect on the neuronal and extraneuronal uptake of noradrenaline by the myocardial tissue. At the highest concentration, it decreased the spontaneous release of the transmitter and enhanced its catabolism. Without any significant effect on tyramine-induced noradrenaline release, taurine decreased the release of the amine induced by dimethylphenylpiperazinium and nerve stimulation. These results suggested that taurine may reduce the peripheral sympathetic activity by accelerating noradrenaline catabolism and decreasing its release probably via its ability to prevent a rise of intracellular calcium ion.