Circadian expression of pineal 5-lipoxygenase mRNA.
In lymphocytes, the pineal hormone, melatonin, suppresses 5-lipoxygenase (5-LO) gene expression. Because circadian fluctuations in melatonin content are prominent in the pineal, we hypothesized that 5-LO mRNA level in this gland is greater when melatonin is low (day) than at night. Using the reverse transcription/polymerase chain reaction we assayed the levels of mRNAs coding for 5-LO, serotonin N-acetyltransferase (NAT), and for a constitutive gene, cyclophilin, in rat pineals obtained at 10:30-11:00 h (day) or 24:30-01:00 (night). Cyclophilin mRNA was not affected by circadian rhythm, whereas 5-LO and NAT were affected in an opposite manner: 5-LO mRNA was high during the day, NAT mRNA at night. We propose that circadian pineal 5-LO expression might play a role in circadian regulation of pineal functioning.
Uz
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T
The Psychiatric Institute, University of Illinois at Chicago, 60612, USA.
Manev
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H
D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism; D002940:Circadian Rhythm / Q000502:physiology*; D003624:Darkness; D004790:Enzyme Induction / Q000502:physiology; D008027:Light; D008084:Lipoxygenase / Q000096:biosynthesis*; D008297:Male; D009841:Oligonucleotides / Q000378:metabolism; D019696:Peptidylprolyl Isomerase / Q000096:biosynthesis; D010870:Pineal Gland / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000302:isolation & purification; D051381:Rats; D011914:Rats, Inbred BN
D009841:Oligonucleotides; D012333:RNA, Messenger; D008084:Lipoxygenase; D001191:Arylamine N-Acetyltransferase; D019696:Peptidylprolyl Isomerase