An increase of neuropeptide Y but not nitric oxide synthase-immunoreactive nerves in the bladder neck from male patients with bladder neck dyssynergia

Abstract

Purpose: To determine the distribution of neuropeptides in male patients with bladder neck dyssynergia and benign prostatic hyperplasia.

Materials and methods: Bladder neck tissue, obtained from male patients with bladder neck dyssynergia (BND) and control patients with benign prostatic hyperplasia (BPH), was studied immunohistochemically for protein gene product 9.5 (a general neuronal marker), vasoactive intestinal polypeptide, neuropeptide Y, calcitonin gene-related peptide, substance P, growth associated protein 43 and nitric oxide synthase.

Results: In the bladder neck from control patients, the greatest density of nerves contained protein gene product 9.5, followed in decreasing order by neuropeptide Y; vasoactive intestinal polypeptide; calcitonin gene-related peptide; nitric oxide synthase; substance P and serotonin. The neuropeptides were found in the smooth muscle and were also associated with blood vessels. In patients with BND there was a statistically significant increase (P < 0.05) in the density of protein gene product 9.5- and neuropeptide Y-immunoreactive nerves in the smooth muscle and the base of the mucosa but not in blood vessels in the bladder neck, while the density of the other neuropeptides studied, nitric oxide synthase and serotonin did not significantly change from that of control tissue. Growth associated protein 43-immunoreactive nerves were absent from the bladder neck from both groups of patients.

Conclusion: It is suggested that the increase in density of protein gene product 9.5- and neuropeptide Y-immunoreactive nerves, part of the sympathetic contractile system of the bladder neck, may exacerbate bladder outlet obstruction and thus play a role in the pathogenesis of BND.