Regeneration of Peripheral Nervous System (PNS) in Rats Under Dietary and/or Endogenous Cholesterol Variations

Both exogenous and endogenous cholesterol are rapidly incorporated into PNS myelin during its formation. We have found that a decrease in endogenous cholesterol induces a retardation in the normal development of the myelin sheath. In order to study the relative importance of these two sources of cholesterol for the myelin formation and maintenance in the present experiments, the regeneration of the sciatic nerve has been used as a model to study myelin formation under conditions of high and low levels of endogenous and exogenous cholesterol. For this, rats (starting a 1 month of age) were subjected to one of the following conditions: a) normal diet; a') normal diet plus treatment with the cholesterol biosynthesis inhibitor AY-9944*; b) 2% cholesterol diet; b') 2% cholesterol diet plus treatment with AY-9944; c) cholesterol free diet; and c') cholesterol free diet plus treatment with AY-9944.