Modulation of noradrenaline uptake and release by taurine in rat cerebral slices

The effects of taurine on the uptake and release of noradrenaline were studied in forebrain slices from control rats and from rats treated with a taurine-free diet supplemented with 2-guanidinoethanesulphonate. Exogenous taurine slightly increased noradrenaline uptake in slices from untreated rats. There were no significant effects by exogenous taurine on spontaneous efflux of noradrenaline. The potassium-stimulated noradrenaline release was enhanced by taurine from frontal cortical slices and suppressed from occipital slices but only in the diet group, in which the endogenous brain taurine concentration had been lowered to one-half of the control concentration. It is suggested that taurine may act via presynaptic alpha-adrenoceptors and/or modify the availability of calcium for the stimulus-secretion coupling process.