Methionine-enkephalin-Arg⁶-Gly⁷-Leu⁸-immunoreactive nerve fibers and cell bodies in lumbar paravertebral ganglia and the celiac-superior mesenteric ganglion complex of the rat: An immunohistochemical study

Lumbar paravertebral ganglia and prevertebral ganglia of the rat were immunohistochemically examined using an antiserum against Methionine-enkephalin-Arg⁶-Gly⁷-Leu⁸ (Met-Enk-Arg-Gly-Leu). Colchicine (5 mg/kg body wt., i.p. injection) was employed as an axonal transport blocker to intensify the immunoreactivity in the nerve cell bodies. In the lumbar paravertebral ganglia of the colchicine-treated rats, about 55% of nerve cell bodies showed a positive immunoreactivity. In the celiac-superior mesenteric ganglion complex, a dense network of positively immunostained nerve fiber varicosities surrounded immunonegative nerve cell bodies. The Met-Enk-Arg-Gly-Leu-like immunoreactivity demonstrated in this study suggests the occurrence of preproenkephalin A and related opioid peptides.