A comparison of fatty acid activation in sciatic nerve and Schwann cell rich cultures from normal and trembler mice

Alteration of sulfatide synthesis in control and Trembler mice during Wallerian degeneration and remyelination

Sulfatide synthesis from sulfate is much greater in the peripheral nerves of the Trembler mouse. After nerve transection, during Wallerian degeneration, this synthesis rate drops down very rapidly in both normal and Trembler mice. Twenty-four hours after permanent transection, the rate of synthesis is reduced by 80% in the mutant and 50% in the normal mouse. Four days after transection, the synthesis rate in the Trembler is only 9% of that observed in intact nerves, and 21% of that in the intact nerves of normal animals. After 5 d the synthesis remains constant. Thus, enhanced synthesis of sulfatides in the Trembler mouse is probably not caused by Wallerian degeneration. After crush of the sciatic nerve, the synthesis rate decreases very rapidly in the normal mouse as it does after permanent transection. But during regeneration, from the 7th day, it rises dramatically and 14 d after crush, a 2.5-fold increase in the synthesis rate is observed, compared to that in the contralateral control nerve. This synthesis rate returns to normal 1 mo after crush. In the Trembler, the synthesis decreases for 2 d after crush and increases from then on, eventually reaching the value of the contralateral control Trembler nerve within 2 mo. In the mutant there is no prominent peak of sulfatide synthesis during regeneration.

Assay of stearoyl-CoA synthesis in microsomes from normal and Trembler mouse sciatic nerves

Using a new one-step technique which allows the characterization and a quantitative assay of long-chain acyl coenzyme A (acyl-CoA), the activity of the stearoyl-CoA synthetase was studied in the membrane fraction from sciatic nerves of normal and Trembler mice. A synthesis of acyl-CoAs was observed in both cases, but, whatever the experimental conditions, there was a two-fold increase of the specific activity of the ligase in the PNS of the Trembler mouse.