Abnormal sulfate metabolism in a hereditary demyelinating neuropathy

Trembler mice are affected by dominantly inherited neuropathy. Total lipid content and sulfatides were decreased in peripheral nerves from 15-day-old mutants. The proportion of sulfatides in per cent of total lipids was similar in control and Trembler nerves. The specific activity of ceramide galactosyltrnsferase, the enzyme responsible for the synthesis of cerebrosides, was 36 and 13% of controls, in young and adult. Trembler nerves, respectively. In contrast, cerebroside sulfotransferase activities were increased by 257 and 172% in young and adult Trembler sciatic nerves, respectively. No activator or inhibitor effect could be demonstrated. In Trembler PNS, Km, Vmax and heat sensitivity of CST differed from controls. Low levels of substrate and high arylsulfatase A activity (218% of controls) could explain the lack of sulfatide accumulation. The increased in vivo sulfate and galactose incorporation into non-lipidic material couild reflect the overproduction of endoneurial and perineurial connective tissue, whereas the high turnover rate of sulfatides could be correlated with intense demyelination and remyelination observed in Trembler PNS.