The effects of ageing and of DSP-4 administration on the micturition characteristics of male Wistar rats.

This study sought to determine the effects of ageing on the in vivo micturition characteristics of male Wistar rats and to assess whether they might be replicated in young rats by using the neurotoxin DSP-4 to lesion locus coeruleus-derived noradrenergic pathways projecting to spinal cord nuclei controlling micturition. Significant age-related changes in micturition patterns were observed. There was a loss of a diurnal rhythm in micturition patterns and a large increase in voided volume, maximal between 21 and 24 months, which was paralleled by an increased water intake. DSP-4 lesions neither altered micturition patterns nor water intake in the young adult rat. DSP-4 induced changes in the pattern of tyrosine hydroxylase-like immunoreactivity (TH-LI), most notably almost complete depletion of TH-LI in the dorsolateral nucleus and retention of TH-LI in lumbosacral autonomic preganglionic nuclei, did not mimic the changes in the pattern of TH-LI seen in aged rats.