Quantitative study of phenol as a neurolytic agent in the urinary bladder.

The endoscopic subtrigonal injection of a 6% aqueous phenol solution is an effective technique for denervating the bladder but its clinical usefulness is limited by unpredictable side effects. This study explored the possibility of making this procedure safer by comparing the neurolytic effects of different concentrations and carriers of phenol. Phenol in 2.5 and 5% solutions in three different carriers (water, glycerine and oil) was injected into the rectovesical pouch in 35 rats. After 3 weeks the bladders were excised and the effects on the density of acetylcholinesterase-positive nerves were assessed in each animal using morphometric techniques. The density of enzyme-containing nerves was reduced by 20% in the phenolised animals when compared with controls. This reduction was maximum when water was used as the carrier for either 2.5 or 5% phenol solutions.