Regulation of the circadian rhythm in pineal melatonin production
Illnerová, H.; Vanĕcek, J.
Physiologia Bohemoslovaca 34 Suppl: 57-61
1985
ISSN/ISBN: 0369-9463 PMID: 2941797 Document Number: 259800
The pineal gland exhibits a circadian rhythm in the activity of N-acetyltransferase, the enzyme responsible for the rhythmic production of melatonin. Our data are consistent with the hypothesis that the N-acetyltransferase rhythm is regulated by a two-oscillator pacemaker. The evening N-acetyltransferase rise is controlled by an evening oscillator coupled to dusk, the morning decline by a morning oscillator coupled to dawn. The phase-relationship between both oscillators may determine the period of high night N-acetyltransferase activity and hence the period of elevated melatonin level. This period is different during long and short days and it may provide animals with information about environmental day duration.