24-Hour variation in the relative expression of heme oxygenase 1 and 2 genes on perirenal fat in normal and high fat fed rats: effect of melatonin treatment.

CANO P; FERNANDEZ-MATEOS P; JIMENEZ-ORTEGA V; SPINEDI E; RIOS J; ESQUIFINO AI

Orlando FL

Congreso; 2011 NAASO Anual Meeting; 2011

NAASO

ABSTRACT BODY: Background: Melatonin have been shown to prevent the deleterious effect of high-fat diets.We analyzed whether melatonin concomitantly administered with a high-fat diet (that induces obesity) may prevent the deleterious effects of this diet on relative expression of the genes for heme oxygenase 1 (HO-1) and 2 (HO-2) in perirenal fat.Methods: Firstly, rats fed with a normal diet were administered melatonin (25 μg/mL drinking water) or vehicle for 9 weeks. Secondly, animals were divided into three groups: two fed with a high-fat diet (35% fat) and melatonin (25 μg/mL) or vehicle in drinking water for 11 weeks, and the control group. Groups of rats were killed at six different time intervals throughout a 24-hr period and the perirenal fat was analyzed for gene expression through real time PCR.Results: In experiment 1, melatonin treatment did not induce changes in the 24-h variations of HO-1 although, disrupted the circadian pattern of HO-2 observed in controls. In experiment 2, rats fed with a high-fat diet, showed a significant increase of HO-1 relative gene expression whereas the concomitant administration of melatonin prevented this increase. Also a disruption of the 24-h. pattern of HO-1 was observed in high-fat fed rats. The pattern of this enzyme in melatonin treated high-fat fed rats was similar to that observed in controlsConclusions: The results suggest that melatonin partially prevented the disruptive effect of a high-fat diet administration to adult rats on the relative expression of HO genes in perirenal fat.