Experimental alterations of the bound state of cerebral lysosomal enzymes

Biochemical changes in unilateral brain injury in the rat: A possible role of free fatty acid accumulation

Cerebral energy metabolism was investigated in rats with the unilateral brain injury produced by the combination of left carotid artery ligation and systemic exposure to hypoxia. ATP and phosphocreatine levels in the left hemisphere were progressively reduced after the hypoxic-ischemic insult. The reduction of high-energy phosphate levels was accompained by an increase in sodium content and a decrease in potassium content. Mitochondria isolated from the damaged hemisphere showed a defect in ATP formation and oxygen uptake with a reduced ATP/O ratio. A large amount of free fatty acids (palmitic, stearic, oleic and arachidonic acids) accumulated in the injured hemisphere. The addition of unsaturated fatty acids (including oleic and arachidonic acids) to mitochondrial preparations caused an impairment of oxidative phosphorylation similar to that observed in mitochodria isolated from the damaged hemisphere.

Effect of vitamin E deficiency on the lipid class and fatty acid composition of rat brain gray and white matter

Three-week old male Sprague-Dawley rats were placed on a control or vitamin E-deficient diet for 9 months. The total lipid and cholesterol contents of brain gray and white matter areas in the vitamin E-deficient group did not differ from controls. The concentration of cerebrosides was lower in white matter but higher in gray matter of deficient animals. However, sulfatide was significantly (P less than 0.001) higher in white and gray matter of deficient animals compared with controls. Lysolecithin was not found in vitamin E-deficient gray matter but was present in control gray matter lipids. No marked differences were found in the concentrations or relative amounts of sphingomyelin, phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl serine, or phosphatidyl inositol in the phospholipids of gray or white matter of vitamin E-deficient rats as compared to controls. In addition, no remarkable differences were found in the fatty acid composition of total lipid extracts of gray or white matter from vitamin E-deficient rats when compared with controls.