Experimental protein-calorie malnutrition in rats: Biochemical and ultrastructural studies

Abstract

Young rats (100–130 gm) fed a low-protein diet which simulates the protein value of diets eaten by children in areas where protein-calorie malnutrition is prevalent developed many of the features associated with kwashiorkor. Among the findings were marked loss in body weight, atrophy of many visceral organs, fatty liver, hypoproteinemia, edema, and profound changes in serum amino acid patterns. Associated with the alterations in serum amino acid levels were extreme disproportions in the fasting levels of amino acids in liver. This experimental model of rodent kwashiorkor showed marked reduction in liver protein and RNA contents, but DNA remained remarkably constant indicating loss of cellular contents rather than decrease in cell population. The decreased RNA content of the liver was consistent with the observations of massive breakdown of the membranes of the endoplasmic reticulum as well as the elevated activity of alkaline ribonuclease assayed in the absence of PCMB. The polysomes showed extensive disaggregation resulting in increased monomer and dimer peaks. The significance of these biochemical and anatomical changes as well as their possible relevance to kwashiorkor in children was discussed.