Circadian rhythm of serotonin N-acetyltransferase activity in rat lens

Citation
M. Abe et al., Circadian rhythm of serotonin N-acetyltransferase activity in rat lens, EXP EYE RES, 70(6), 2000, pp. 805-808
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
da verificare
Journal title
EXPERIMENTAL EYE RESEARCH
ISSN journal
0014-4835 → ACNP
Volume
70
Issue
6
Year of publication
2000
Pages
805 - 808
Database
ISI
SICI code
0014-4835(200006)70:6<805:CROSNA>2.0.ZU;2-0
Abstract
Activity of serotonin N-acetyltransferase (NAT), a key regulatory enzyme in melatonin biosynthesis, was detected in the rat lens. NAT activity in the lens showed significant diurnal variation in vivo and in vitro, peaking dur ing the period of darkness, when the lenses were maintained under 14 hr lig ht/10 hr dark cycle. Cultured lenses exhibited a circadian rhythm of NAT ac tivity when maintained under constant darkness. However, the rhythm in vitr o was not entrained when the light/dark cycle was delayed 8 hr from the cyc le in intact animals. These data strongly suggest that the rat lens contain s a circadian clock that controls NAT activity. although the circadian cloc k appears to lack a photic entrainment mechanism. (C) 2000 Academic Press.