ZINC LIMITED DIET MODIFIES THE EXPRESSION OF THE RATE-REGULATORY ENZYMES INVOLVED IN PHOSPHATIDYLCHOLINE AND CHOLESTEROL SYNTHESIS

NIDIA NOEMÍ GOMEZ; VERÓNICA SILVINA BIAGGIO; ESTEBAN JAVIER ROZZEN,; SILVINA MÓNICA ALVAREZ; MARÍA SOFÍA GIMENEZ

BRITISH JOURNAL OF NUTRITION

Nutrition Society

Lugar: Inglaterra; Año: 2006

0007-1145

ABSTRACT Suboptimal intake of zinc is one of the most common nutritional worldwide problems. Previously, we showed that Zinc deficiency produces alterations in lung lipid metabolism in rats. We studied the effect of Zinc limited (ZL) diet on the expression of the enzymes involved in phosphatidylcholine and cholesterol synthesis. After two months of treatment with a ZL diet we found important variations in lipid content of Wistar male rats: triglycerides (TG) decreased a 60% (p<0.001) while esterified cholesterol (EC), free cholesterol (FC) and phospholipids (PL) increased in 66%, 24% and 25% respectively. We also observed a decrease of 40% in the amount of 3H incorporated into TG and an increase of 47% and 28% in the 3H incorporated to PL and EC respectively. Fatty acid synthase (FAS) and G6PDH activity was increased (p<0.01 and p<0.05 respectively). Glycerol-3-phosphate acyltransferase (GPAT), lipoprotein lipase (LPL), diacyl glycerol acyl transferase (DGAT), and 3-hydroxy-3- methylglutaryl coenzyme A reductase (HMGCoAR) expression decreased (p<0.01 in all the cases), while acetyl CoA carboxylase (ACC) and cholinephosphate cytidylyltransferase (CT) increased (p<0.01 and p<0.005 respectively). These results suggest that ZL alters the expression of enzymes involved in phosphatidylcholine and cholesterol synthesis, which could lead to increased PL and Cholesterol and decreased TG. This study suggests that major changes in the lipid composition of lung are induced by a Zinc Limited condition. Therefore, Zinc deficiency must be taken into account in order to design therapies and public health interventions such as zinc supplementation for high-risk subjects or certain diseases, as asthma. Keywords: lung, zinc deficiency, phospholipid (PL), Cholesterol, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCoAR)