Pineal Serotonin N-acetyltransferase Activity Research Articles

Dark induced increase in pineal serotonin N-acetyltransferase activity: a refractory period.

Nachweis, dass Ratten, aus normaler Lichtperiode abrupt in Dunkelheit versetzt, keine Zunahme der NATase-Aktivitat im Pinealorgan zeigen und dass Isoproterenol-Injektion die Zunahme der NATase auslost.

Rapid light-induced decrease in pineal serotonin N-acetyltransferase activity.

Light acting by way of the eye causes the dark-induced activity of serotonin N-acetyltransferase in the pineal gland of the rat to decrease with a halving time of about 3 minutes. This effect, which is one of the more rapid physiological changes known to occur in the activity of any enzyme that metabolizes biogenic amines, appears to explain the rapid increase in the concentration of pineal serotonin that is caused by light exposure at night.