Effect of substance P on detrusor muscle in rats with diabetic cystopathy

Diabetic cystopathy (DCP) is a well known complication in diabetes mellitus (DM). In the present experimental study, DM was induced in rats by streptozotocin and DCP was confirmed on cystometry. In vitro studies on detrusor strips from diabetic rats showed an increased contractile response to substance P (SP) compared with controls, indicating denervation supersensitivity. A decreased response to capsaicin in diabetic detrusor strips indicated a decreased neuronal content of SP or a diminished number of SP-containing sensory nerves. This suggests that DM induces alterations in nerves containing SP which may be at least partly responsible for sensory loss and the development of DCP.