Brain myelin of genetically obese mice

Brain myelin was studied in genetically obese (ob/ob) mice and compared with that of normal ( + +) mice from the same strain. The brain from obese mice had a significantly lower amount of myelin, and marked changes in the fatty acid composition of myelin were observed. In contrast, the myelin cholesterol : phospholipid : galactolipid and the cerebroside : sulfatide molar ratios and also the phospholipid composition were normal. 2′, 3′-Cyclic nucleotide 3′-phosphohydrolase (CNP) and UDP-galactose ceramide galactosyltransferase (CGalT) enzymatic activities were normal, and 3′-phosphoadenosine 5′-phosphosulfate (PAPS) : cerebroside sulfotransferase (CST) was only slightly decreased. Cholesterol esters were not present in the mutant. These results indicate that brain myelination is affected in obese mutant mice.