[3H]phorbol 12,13-dibutyrate/PKC binding in thoracic spinal cord: no change in amyotrophic lateral sclerosis

[3H]phorbol 12,13-dibutyrate ([3H]PDBu), a selective ligand for various protein kinase C isozymes (PKC), was used to investigate the distribution of [3H]PDBu/PKC binding sites in thoracic spinal cords of patients who died with amyotrophic lateral sclerosis (ALS) and subjects free of neurological disease. In controls, binding of [3H]PDBu was mostly concentrated in the substantia gelatinosa and to a lesser extent in other dorsal horn regions (laminae III and IV). [3H]PDBu binding sites were also present in the ventral horn and laminae X but in somewhat lower quantities. The distribution of [3H]PDBu binding in thoracic spinal cords of patients who died with ALS was unchanged compared to controls and no significant differences were observed in the amount of specific binding in ALS. The present results on the distribution of [3H]PDBu binding sites in human spinal cord are consistent with previous studies of [3H]PDBu binding in rodents indicating that high levels of PKC are present in the dorsal horn. The results also suggest that levels of PKC isozymes are not altered in ALS spinal cord.