Taurine release from the pineal-gland is stimulated via a beta-adrenergic mechanism

Pineal glands were prelabeled in organ culture with [14C]taurine, and then treated with biogenic amines. The rate of release of [14C]taurine was rapidly elevated by low concentrations of norepinephrine, apparently acting through a beta-adrenergic mechanism. The release was probably not due to a nonspecific change in membrane permeability, as a comparable release was not seen with [14C]glycine and [14C]alpha-aminoisobutyric acid. These findings suggest that the release of taurine may be related to or a reflection of the early events in adrenergic activation of the pineal gland, such as hyperpolarization of pinealocytes. The released taurine might also have an extracellular role as it has been recently shown that extracellular taurine can interact with pineal beta-adrenergic receptors to stimulate melatonin production. Thus, the released taurine could possibly act as an extracellular feedback messenger.