The alterations of norepinephrine and acetylcholine concentrations in immature rat urinary bladder caused by streptozotocin-induced diabetes.

The concentrations of norepinephrine (NE) and acetylcholine (ACh) in the body and base of the bladder were investigated two, four and eight weeks after the administration of streptozotocin to four-week-old rats. At four and eight weeks after following dosage, NE concentrations in the base of the bladder of the diabetic rats were significantly higher than those of control rats. At the two-week diabetic condition, ACh concentrations in both the body and base of the bladder diabetic rats were about two-fold higher than in the respective control levels and remained constant for eight weeks. However, the control rats showed dramatic increase in ACh concentration from two to four weeks after dosage. There was no significant difference in the response of bladder muscle strips to phenylephrine, isoproterenol and ACh in the diabetic vs. control rats throughout the experiment. These observations suggest that the alteration of autonomic nervous system may occur at an early stage of diabetes mellitus in immature rats and that the high concentration of NE in the diabetic bladder base may reflect an adaptive overfunction of the adrenergic system probably to maintain continence. Furthermore, the lack of change in ACh concentration with age in diabetic rats may suggest an impaired development of the cholinergic system.