110/140 laminin-binding protein immunoreactivity in spinal dorsal root ganglia: a capsaicin-insensitive reduction induced by constriction injury of the sciatic nerve in rats.

The distribution of 110/140 laminin-binding protein (110/140 LBP) in the spinal dorsal root ganglia (DRG) and its regulation by partial constriction of the sciatic nerve was studied in adult rats. The cross-sectional area of neurons with 110/140 LBP-immunoreactivity (-I) showed an approximately normal frequency distribution. The 110/140 LBP-I was observed in neuronal cell bodies exclusive of the nucleus. Following sciatic nerve constriction, the 110/140 LBP-I was downregulated in the ipsilateral L4-5 DRG. DRG neurons with a cross-sectional area > or = 1600 microns 2 were preferentially affected. Neonatal capsaicin-treatment, a procedure that selectively destroys a subpopulation of DRG neurons with fine unmyelinated axons, had no effect on the reduction of 110/140 LBP in the DRG induced by sciatic nerve constriction. Western immunoblot analysis confirmed a reduction of 110/140 LBP on the side ipsilateral to the constriction. These results demonstrate a LBP within primary sensory neurons and its suppression by peripheral nerve injury. The data support a role for LBP in the adult nervous system.