IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
artículos
Título:
Effect of lithium on melatonin production in the pineal gland of viscacha
Autor/es:
L. FUENTES; C. CALDERON; S. GARCIA ASEFF; E. MUÑOZ; M. MOLLER; L. PELZER
Revista:
BIOLOGICAL RHYTHM RESEARCH
Referencias:
Año: 2008 vol. 39 p. 43 - 55
ISSN:
0929-1016
Resumen:
Melatonin is synthesized primarily in the pineal gland. Lithium affects the circadian rhythms that may explain its therapeutics effectiveness in the treatment of bipolar disorder. The objective of this study was to investigate the effect of lithium on the biochemical parameters involved in melatonin synthesis in the pineal gland of viscacha.  Viscachas were daily intraperitoneally injected with lithium chloride or saline solution for one month. Pineal mRNAs encoding b1-adrenoceptor and arylalkylamine-N-acetyltransferase enzyme (AA-NAT) were studied by in situ hybridization. Pineal melatonin concentrations were determined by radioimmunoassay, and AA-NAT and hydroxyindol-O-methyltransferase (HIOMT) activities were investigated by radiometric assays. The only parameters that decreased significantly were the expression of AA-NAT mRNA and pineal melatonin levels. Our data suggest that lithium treatment may decrease melatonin synthesis in the viscacha pineal gland by a complex mechanism that involves currently unknown events that are beyond a decrease in the expression of AA-NAT enzyme.