Acetyl-L-carnitine prevents substance P loss in the sciatic nerve and lumbar spinal cord of diabetic animals.

Diabetic neuropathy is a disease of peripheral nerves, characterized by axonal atrophy and degeneration that might be preceded by a marked impairment of axonal transport and by a reduced conduction velocity. Sensory nerves are particularly susceptible to diabetes. In the present report it is shown that experimental diabetes in rats causes a significant reduction of the content of the pain-related neuropeptide substance P in sciatic nerve and lumbar spinal cord. Such a loss of substance P is fully prevented by acetyl-L-carnitine treatment. The neuroprotective pharmacological effect is selective and takes place without significant changes of hyperglycaemia and without modifications of the reduced rate of body growth typical of diabetic animals.