The effect of phentolamine on synaptosomal phosphatidylinositol in experimental galactose toxicity.

Abnormal myo-[2-3H]inositol incorporation into phosphatidylinositol has been found in phentolamine-treated synaptosomes that were isolated from the cerebral hemispheres of galactose toxic rats and incubated with [33P]Pi and myo-[2-3H] inositol. In galactose toxic rats phentolamine-stimulated myo-[2-3H]inositol labeling of phosphatidylinositol was 70% greater than in normal animals. This enhanced labeling of synaptosomal phosphatidylinositol in galactose toxic rats during stimulation with phentolamine is in marked contrast to the depressed myo-inositol labeling of phosphatidylinositol reported with acetylcholine stimulation.