Behavioural and molecular rhythmic parameters are modified in vitamin A-deficient rats.

NAVIGATORE FONZO L; DELGADO S.M; GIMENEZ, M S; ANZULOVICH, AC

Mendoza

Congreso; XXVIII Reunión Científica Anual de la Sociedad de Biologia de Cuyo y la II Reunión de la dirección de Investigación de Ciencia y Técnica,; 2010

Sociedad de Biologia de Cuyo

SCN synchronizes peripheral clocks primarily through temporal feeding patterns that are imposed through behavioral rest-activity cycles. However, diffusible signals involved in this temporal synchronization are not completely revealed. Some evidence points out retinoids as regulators of clock genes activity through their retinoid nuclear receptors, RARs and RXRs. Our objective was to investigate the effect of a vitamin A-deficient diet on the rest-activity cycles of Holtzman rats as well as on the daily expression of RARa, RXRb and clock genes in the rat hippocampus. RNA was extracted from hippocampus using the Trizol reagent. Transcript levels of RARa, RXRb, Bmal1, Per1 and Cry 1 were determined by RT-PCR. RARa, RXRb, BMAL1, and PER1 protein levels were determined by Western blot. We observed a rhythmic variation in the RARa, RXRb, BMAL1, PER1 protein levels during a 24-h period, consistent with their daily mRNA expression. Vitamin A deficiency modified the daily pattern of retinoid nuclear receptors and clock genes expression as well as locomotor activity in rat.