Taurine: stimulation of pineal N-acetyltransferase activity and melatonin production via a beta-adrenergic mechanism.

Pineal glands convert [3H]tryptophan to [3H]N-acetylserotonin and [3H]melatonin in organ culture. Taurine treatment increases the rate of production of these compounds 40- and 25-fold respectively by stimulating the activity of N-acetyltransferase. This stimulation is blocked stereospecifically by L-propranolol, indicating that taurine is probably acting via beta-adrenergic receptors. Taurine is active in stimulating N-acetyltransferase activity in denervated glands, suggesting that it might interact directly with the beta-adrenergic receptor, and not by causing the release of norepinephrine from nerve terminals.