Peroxisomes and the hepatic pathology of childhood malnutrition

RESUMO

Liver specimens obtained immediately after death from eight severly malnourished children were examined by electron microscopy, and compared with seven liver biopsy specimens from children who recovered from malnutrition. The liver cells from the fatal cases showed mitochondrial swelling, with coarse densities in the matrix, cholestasis, depletion of the endoplasmic reticulum and Golgi apparatus, diminished glycogen stores, prominent lipid deposits and focal cytoplasmic degradation. The nucleoli were enlarged. There was marked reducation in peroxisomes. In contrast, the biopsies from recovering children showed good cellular organisation, and a normal frequency of peroxisomes. Multiple factors, including sepsis, may lead to depletion of peroxisomes. Loss of peroximes may interrupt beta-oxidation of long-chain fatty acids and accentuate the accumulation of lipid. Moreover, a reduction in the concentration of catalase may remove one avenue for the detoxification of free radicals. As the concentration of other anti-oxidants, notably glutathione, is also reduced, free radical damage may occur, leading to lipid peroxidation of membranes, mitochondrial damage, pump failure and influx of water and electrolyted into the cell.