Hexanedione effects on protein phosphorylation in rat peripheral nerve

Rats were treated with either 2,5-hexanedione (2,5-HD), 1,6-hexanediol (1,6-HDIOL), or saline for 7, 15 or 24 days. Protein phosphorylation was measured in proximal and distal sciatic nerve segments following incubation with [³²P]orthophosphate. In proximal segments, 2,5-HD administration caused selective time-dependent increases in isotope incorporation in a 55 kDa protein, tentatively identified as tubulin, and a 180 kDa protein. Enhanced phosphorylation was highest at 24 days when motor function was most impaired. Administration of 1,6-HDIOL produced no consistent phosphorylation changes. Animals intoxicated with 3,4-dimethyl-2,5-hexanedione for 12 days showed proximal region increases in phosphorylation of the 55 and 180 kDa proteins and the major myelin proteins, P_o and P_r.