Effects of pre- and postweaning undernutrition on polyphosphoinositide pools in rat kidney

The effects of undernutrition on polyphosphoinositide levels in rat kidneys removed and frozen immediately after animal death or 10 min later were determined. Weanling (21-day-old) rats of dams fed a 5 or 22% protein diet and litters fed either normal or protein-deficient diets for an additional six wk were used. Nutritional deprivation lowered phosphatidylinositol-4-phosphate (PtdIns4P) preferentially (35-40%) but preserved phosphatidylinositol-4,5-bisphosphate (PtdIns4,5P2) at weaning. This effect was not completely reversed in animals nutritionally rehabilitated after weaning. Postweaning protein deficiency did not reduce the levels of these lipids. Postmortem loss was the same for all five groups, minimal for PtdIns4P and about one-third for PtdIns4,5P2.