A study of bladder dysfunction during streptozotocin-induced diabetes in the rat using an in vitro whole bladder preparation.

An in vitro whole bladder preparation has been used in this study to examine the effects of eight and 16 week streptozotocin-induced diabetes on detrusor function in the rat. In eight week animals cystometric recordings showed an increase in bladder capacity associated with a decrease in intraluminal pressure. Concentration-response curves revealed a significant increase in sensitivity of the detrusor to beta,gamma-methylene ATP, a potent purinergic agonist, and a trend towards subsensitivity to acetylcholine in bladders from eight week diabetic rats when compared to controls. The atropine-resistant (purinergic) response to neurogenic stimulation was increased over the frequency range two to 30 Hz and was significantly greater at two Hz. In 16 week animals the cystometrogram had partially recovered; capacity had decreased compared to eight week diabetics and intraluminal pressure was within the normal range. Concentration-response curves revealed no significant difference in the response to acetylcholine and a greatly reduced response to beta,gamma-methylene ATP in the 16 week diabetics compared to controls. The atropine-resistant neurogenic response was slightly, but not significantly reduced. The results are discussed in relation to clinical urodynamic measurements of human detrusor dysfunction in diabetes.