Changes of lipoamide dehydrogenase and mitochondrial structure in selenium-deficient chicks
Shih, J.C.; Sandholm, M.; Scott, M.L.
Journal of Nutrition 107(9): 1583-1589
1977
ISSN/ISBN: 0022-3166 PMID: 330828 Document Number: 114413
Male Plymouth Rock X Vantress chicks 1 day old, the progeny of hens fed on a diet low in Se and vitamin E, were fed on a basal diet with ethoxyquin and high level of vitamin E to prevent encephalomalacia and exudative diathesis. The basal diet with added taurocholate was given alone or with sodium selenite to give Se 0.02 to 0.15 mg/kg diet. To estimate its possible effect on growth DL-lipoic acid was added to the diet, with Se 0.02 mg/kg, at none, 12.5, 25 or 50 mg/kg. At different ages some chickens were killed and tissues were homogenized and cellular components were fractionated on a sucrose gradient. With low marginal Se lipoic acid had little or no effect on growth. In the Se-deficient chicks 3 weeks old pyruvate, alpha -ketoglutarate and lipoamide dehydrogenases decreased in crude extracts of pancreas, increased in liver and were unchanged in cardiac tissue. In pancreas and liver the ratio of mitochondrial to the supernatant or cytosolic enzyme activities decreased as Se in the diet decreased, indicating large changes in mitochondrial membranes whereby as the membranes were damaged, the lipoamide dehydrogenase was released from the mitochondria into the cytosol. The findings suggested an increase in fragility of mitochondrial membranes in Se-deficient chickens.