Vasoactive intestinal polypeptide concentration in human bladder neck smooth muscle and its influence on urodynamic parameters.

Three human studies were performed to evaluate the influence of vasoactive intestinal polypeptide (VIP) on bladder and urethral function. Bladder neck smooth muscle biopsies were obtained from nine men with functional bladder neck obstruction, from 10 men with medium sized benign prostatic hypertrophy and from four patients with a normal infravesical outlet. The biopsies were analysed for VIP by radioimmunoassay and by immunohistochemistry. No differences were found between the groups. Pressure-flow-EMG studies were performed in five men and urethrocystometry was performed in six women at rest, repeated coughing and at squeezing before, during and after VIP 3 micrograms/kg X h intravenously. No systematic changes developed in any of the urodynamic parameters.