Lack of in vitro ceramide formation in the PNS of trembler mice.
The amidification of sphingosine by acyl donors has been investigated in a microsomal fraction prepared from sciatic nerves of normal and Trembler mice. In the control, a ceramide synthesis is observed in the presence of acyl-CoAs and not with free fatty acids. The synthesis increases as a function of the protein amount and the time and is dependent on acyl-CoA concentration. The level of synthesis is highly similar to that observed in vivo after palmitate injection into the sciatic nerves of normal mice. In the mutant, there is a major abnormality because a weak synthesis (20% of the control) is observed only with high acyl-CoA concentration (greater than 200 microM), whereas in the range of the physiological acyl-CoA concentrations (less than 20 microM), there is no ceramide formation from stearoyl-CoA or lignoceroyl-CoA.
Boiron-Sargueil
F
F
IBCN-CNRS, Université de Bordeaux II, France.
Heape
A
A
Cassagne
C
C
D000214:Acyl Coenzyme A / Q000502:physiology; D000818:Animals; D002458:Cell Fractionation; D002518:Ceramides / Q000032:analysis / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D051379:Mice; D008808:Mice, Inbred CBA; D008818:Mice, Neurologic Mutants; D010525:Peripheral Nerves / Q000737:chemistry / Q000378:metabolism*; D012584:Sciatic Nerve / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors
D000214:Acyl Coenzyme A; D002518:Ceramides