Age-dependency and regional distribution of enkephalinergic nerves in human prostate

The regional distribution of peptidergic nerves in the juvenile and adult human prostate has been studied immunohistochemically using highly specific polyclonal antibodies. Nerves displaying immunoreactivity of Met-enkephalin, Leu-enkephalin, heptapeptide and octapeptide were detected in the dorsolateral stroma closely related to smooth muscle predominantly of juvenile glands. A less strong immunoreactivity was present around stromal vessels and periurethral. Subepithelial peri-acinar nerves showing Leu-enkephalin, Met-enkephalin, octa- and heptapeptide immunoreactivity were found in a few instances. The most prominent immunoreaction was achieved with octapeptide antiserum, followed in decreasing order by Met-enkephalin, Leu-enkephalin and heptapeptide. Their density decreased with age. Antisera against beta-endorphin, alpha-neoendorphin, beta-neoendorphin and dynorphin A gave to positive immunoreaction with prostatic nerves. The regional distribution pattern described is in favor of a postsynaptic peptidergic sympathetic innervation of prostatic stroma acting with classical neurotransmitters.