Highlights Relation of Cell Metabolism to Nutritional State
In severe protein-calorie malnutrition (PCM) in children (Kwashiorkor and/or Marasmus) cellular energy metabolism is impaired. Using muscle biopsies or circulating leukocytes for cell studies, PCM is characterized by accumulation of cell Na, with reduction of K and Mg. Cell metabolite levels, associated with utilization of glucose and with turnover of the citric acid cycle, are reduced. The electrolyte changes are related to simultaneous changes in cell metabolite levels. Activities of some regulatory enzymes in the glycolytic and citric acid cycle pathways are impaired. The inhibition of pyruvate kinase, for example, represents an allosteric effect related to the high Na level in the cell. Cell energy levels are reduced and appear to limit the effectiveness of the Na pump. Plasma amino acid levels and amino acid uptake by cells are abnormal. Phagocytosis by leukocytes is impaired and this is related to impaired glycolysis and depressed hexose monophosphate shunt activity. Death in PCM is associated with exaggeration of the cell metabolic abnormalities leading to a breakdown in cell energy production. Recovery is associated with improvement in cell substrate and energy levels.
KeywordsPyruvate Kinase Citric Acid Cycle Trace Mineral Adenylate Kinase Amino Acid Uptake
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