Relationship between Pineal N-Acetyltransferase Activity, Pineal Melatonin and Serum Melatonin in Rats under Different Lighting Conditions

Pineal N-acetyltransferase (NATase) activity has often been used as an indicator of pineal melatonin (MT) production, and the rhythms of pineal and serum MT levels are assumed to be parallel. However, these issues require further examination in view of some recent findings. In the present study, the 24-hour rhythms of pineal NATase, pineal MT content and serum MT concentrations were examined in groups of rats exposed to four artificial lighting …