BEHAVIOURAL AND MOLECULAR RHYTHMIC PARAMETERS ARE MODIFIED IN VITAMIN A-DEFICIENT RATS

NAVIGATORE FONZO LS; DELGADO SM; GIMÉNEZ MS; ANZULOVICH AC

Mendoza

Congreso; XXVIII Reunión Científica Anual de la Soc. de Biología de Cuyo; 2010

Soc. Biol. de Cuyo

SCN synchronizes peripheral clocks primarily through temporalfeeding patterns that are imposed through behavioral rest-activitycycles. However, diffusible signals involved in this temporal synchronizationare not completely revealed. Some evidence pointsout retinoids as regulators of clock genes activity through their retinoidnuclear receptors, RARs and RXRs. Our objective was toinvestigate the effect of a vitamin A-deficient diet on the rest-activitycycles of Holtzman rats as well as on the daily expression ofRARa, RXRb and clock genes in the rat hippocampus. RNA wasextracted from hippocampus using the Trizol reagent. Transcriptlevels of RARa, RXRb, Bmal1, Per1 and Cry 1 were determinedby RT-PCR. RARa, RXRb, BMAL1, and PER1 protein levels weredetermined by Western blot. We observed a rhythmic variation inthe RARa, RXRb, BMAL1, PER1 protein levels during a 24-h period,consistent with their daily mRNA expression. Vitamin A deficiencymodified the daily pattern of retinoid nuclear receptors andclock genes expression as well as locomotor activity in rat.Supported by NIH Grant R01-TW006974 funded by the FIC, USA.