Ontogenesis of hydroxyindole-O-methyltransferase gene expression and activity in the rat pineal gland.
Postnatal development of hydroxyindole-O-methyltransferase (HIOMT) mRNA expression, HIOMT activity and melatonin content was investigated in the rat pineal gland from birth to adulthood (62-day old). For each age, animals were sacrificed at two different time-points: midday and midnight. HIOMT mRNA was first detectable one day after birth and maximal diurnal levels were reached at the end of the first week. A 2-fold nocturnal increase appeared significantly 11 days after birth. HIOMT activity was detectable from 5 days of life and significant day/night variations did not appear before 21 days after birth. Appearance of melatonin synthesis and rhythm followed that of HIOMT mRNA. The 10-day delay observed between the appearance of the nocturnal increase in HIOMT activity and expression is discussed in term of differential regulation of both HIOMT mRNA expression and HIOMT activity.
Ribelayga
C
C
Neurobiologie des Fonctions Rythmiques et Saisonnières, UMR-CNRS 7518, Université Louis Pasteur, 12, rue de l'Université, F-67000, Strasbourg, France.
Gauer
F
F
Pévet
P
P
Simonneaux
V
V
D000121:Acetylserotonin O-Methyltransferase / Q000096:biosynthesis / Q000235:genetics*; D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D002940:Circadian Rhythm; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D008297:Male; D010870:Pineal Gland / Q000201:enzymology* / Q000254:growth & development / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D014158:Transcription, Genetic
D012333:RNA, Messenger; D000121:Acetylserotonin O-Methyltransferase