NEUROPEPTIDERGIC INNERVATION OF THE HUMAN MALE DISTAL URETHRA AND INTRINSIC EXTERNAL URETHRAL SPHINCTER

The innervation of the human male distal urethra and intrinsic externa l urethral sphincter was investigated by immunohistochemical technique s. The innervation density was low. In the urethra neuropeptide, and v asoactive intestinal polypeptide positive nerves were found in the mus cular layer, calcitonin gene-related peptide, galanin and PHI nerves w ere localized in the epithelium. In the intrinsic external urethral sp hincter NPY and galanin nerves were quite numerous between the striate d muscle bundles, calcitonin gene-related peptide, vasoactive intestin al polypeptide and PHI were only seen occasionally as thin fibres.