Coexistence of cholecystokinin- and substance P-like peptides in neurons of the dorsal root ganglia of the rat.

Using the indirect immunohistochemical technique with antisera to cholecystokinin and to substance P, the spinal dorsal horn and dorsal root ganglia of normal and colchicine-treated rats were studied. In the spinal cord a similar distribution of substance P- and cholecystokinin-positive networks in the superficial layers of the dorsal horn was observed. In the dorsal root ganglia several cholecystokinin and substance P immunoreactive cell bodies were seen in colchicine-treated rats. After elution and restaining for substance P, of sections previously stained for cholecystokinin, it was found that all cholecystokinin-positive cells also contained substance P-like immunoreactivity and vice versa.