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

Abstract

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) on liver Δ5 and Δ6 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 dam and pup liver phospholipids. It was observed that malnutrition affects milk and liver fatty-acid composition specially in those dams receiving corn oil. Similar results were obtained in liver fatty-acid composition of dams and pups. The rate of liver Δ6 and Δ5 desaturation was measured using [1- 14C]18:2n-6 and [1- 14C]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 Δ5 and Δ6 desaturase activities, in both dams and pups. Feeding dam rats with soy oil during gestation and lactation results in an increase of both Δ6 and Δ5 desaturation activities, even in 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.