Circadian expression of serotonin N-acetyltransferase mRNA in the rat retina.
To investigate the molecular mechanism of the melatonin rhythm in the mammalian retina, we examined the temporal mRNA expression pattern of serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AA-NAT; the rate-limiting enzyme in melatonin synthesis) in the rat retina. Northern blot analysis showed that in a daily light-dark cycle retinal AA-NAT mRNA was low during the day and increased more than threefold at night, and this daily rhythm persisted even in constant darkness. These findings suggest that AA-NAT mRNA expression in the rat retina is regulated by an endogenous circadian clock.
Sakamoto
K
K
National Institute of Bioscience and Human Technology, Agency of Industrial Science and Technology, MITI, Tsukuba, Ibaraki, Japan.
Ishida
N
N
D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000096:biosynthesis / Q000235:genetics*; D015152:Blotting, Northern; D002940:Circadian Rhythm / Q000235:genetics; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000201:enzymology*
D012333:RNA, Messenger; D001191:Arylamine N-Acetyltransferase