Marı́a F. Zafra

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The in vivo dipyridamole treatment for 16 days produced a significant decrease in chick plasma cholesterol, mainly due to the esterified form. This effect was especially patent in the VLDL + LDL fraction. Similar results were observed in triglyceride content. To our knowledge, this is the first report on this hypolipidemic effects of dipyridamole. Total and(More)
Experimental hyperphenylalaninemia has been induced in 5-day-old chicks by dietary treatments with phenylalanine and α-methylphenylalanine. An increase of nearly 8-fold in plasma Phe/Tyr ratio was found after 4 days of supplementation the standard diet with 5% phenylalanine plus 0.4% α-methylphenylalanine. The increase in this ratio was about 13-fold after(More)
Supplementation of 10 or 20% coconut oil in the diet for 1-2 weeks produced a significant hypercholesterolemia in neonatal chicks. Plasma triacylglycerol concentration significantly increased after the addition of 20% coconut oil for 2 weeks. These results show that newborn chicks are more sensitive to saturated fatty acids from coconut oil than adult(More)
Supplementation of coconut oil to the diet for 1-2 weeks produced a significant hypercholesterolemia in 14-day-old chicks. Changes in plasma fatty acid composition correlated positively with those of diets. In this study, we have shown a different response of low- and high-density lipoprotein (LDL and HDL) fractions to dietary saturated fat (coconut oil)(More)
Serum lipoproteins from 12h fasted male chicks (15-day-old) were separated into 20 fractions by isopycnic density gradient ultracentrifugation. A new procedure was described by collecting the different fractions from the bottom of tube instead of by aspiration from the meniscus of each tube. Analyses of chemical composition of serum lipoproteins have(More)
Phenylalanine, phenylpyruvate and phenylacetate produced a considerable inhibition of chick liver mevalonate 5-pyrophosphate decarboxylase while mevalonate kinase and mevalonate 5-phosphate kinase were not significantly affected. Phenolic derivatives of phenylalanine produced a similar inhibition of decarboxylase activity than that found in the presence of(More)
The effect of protein/lipid ratio of diets on hepatic cholesterol has been studied in European eel and correlated with changes in the main enzymes responsible for cholesterol metabolism. The growth rates of animals were similar when dietary lipid level was 12%. However, a 25% protein/20% fat (25/20) diet produced a decrease in the weight gain when compared(More)
Very small sample sizes frequently become the limiting factor in biochemical and biomembrane studies in which routine quantification of protein and bulk lipids are required. The procedure described here allows the simultaneous determination of protein and lipid without initial, multiple aliquots. The method is based on the quantitative precipitation of(More)
Both 5% cholesterol feeding and fasting produced a decrease in the hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity, although certain diurnal variations remained during the second day of treatment. Supplementation of 5% cholesterol to the diet produced a significant increase in cholesterol content of hepatic microsomes, whereas no significant(More)
Phenylalanine and its phenyl metabolites produced a clear inhibition of chick brain mevalonate 5-pyrophosphate decarboxylase, while mevalonate kinase and mevalonate 5-phosphate kinase were not significantly affected. Phenolic derivatives produced a similar or higher inhibition than that found in the presence of phenyl metabolites. The inhibition was(More)