CNS induced neurogenic cystitis is associated with bladder mast cell degranulation in the rat.

PURPOSE To determine if bladder mast cell degranulation is involved in the genesis of neurogenic cystitis induced by pseudorabies virus (PRV) invasion of the central nervous system (CNS). MATERIALS AND METHODS Rats received a total of 4 x 106 plaque forming units (pfu) of PRV-Bartha in the abductor caudalis dorsalis (ACD) muscle. Granulated bladder mast cells per mm2 of bladder tissue and urine histamine content were monitored as the cystitis developed over the next few days. In a subgroup of rats, intravesical resiniferatoxin was used to remove capsaicin-sensitive sensory bladder afferents, while another subgroup was pretreated with a mast cell degranulator. RESULTS PRV injection into the ACD muscle leads to neurogenic cystitis. Histamine levels were elevated in the urine of virus injected rats before any behavioral or microscopical signs of cystitis were present. When the cystitis became clinically manifest, urine histamine returned to control levels, and the number of granulated mast cells dropped significantly. Rats in which capsaicin-sensitive afferents had been removed did not show any signs of cystitis, or increase in urine histamine, or change in the number of granulated mast cells. Pretreatment of animals with a mast cell degranulator completely prevented the appearance of cystitis without altering the CNS disease. CONCLUSION These results provide further evidence that mast cells are involved in neurogenic cystitis induced by changes in CNS activity.