Relationship between dietary oil during gestation and lactation and biosynthesis of polyunsaturated fatty acids in control and in malnourished dam and pup rats

Protein-calorie malnutrition during gestation and lactation affects the fatty-acid desaturase activities, and hence the fatty-acid composition of developing tissues. Wistar rats were fed protein-calorie-deficient diets during gestation and lactation, and the influence of different oils (either corn or soy oil) an liver Delta 5 and Delta 6 desaturase activities was studied. Dam and pup growth was monitored until 18 days' postpartum, fatty-acid composition was determined in milk, as well as in darn and pup liver phospholipids. It was observed that malnutrition affects milk and liver fatty-acid composition specially in those dams receiving cam ail. Similar results were obtained in liver fatty-acid composition of dams and pups. The rate of liver Delta 6 and Delta 5 desaturation was measured using [1-C-14]18:2n-6 and [1-C-14]20:3n-6 as substrate, and the conversion of precursor to product was determined by reverse-phase high-pressure liquid chromatography. Protein-calorie malnutrition produced a reduction in liver Delta 5 and Delta 6 desaturase activities, in both dams and pups. Feeding dam rats with soy oil during gestation and lactation results in an increase of both Delta 6 and Delta 5 desaturation activities, even ill malnourished animals, in comparison with those receiving corn oil. These observations could be helpful to devise a nutritional strategy related to polyunsaturated fatty-acid supply for the normal growth and tissue development. (J. Nutr. Biochem. 9:388-395, 1998) (C) Elsevier Science Inc.1998.