NEUROGENIC INFLAMMATION OF GUINEA-PIG BLADDER

CAPSAICIN, substance P, and ovalbumin, instilled into the bladders of naive and ovalbumin (OVA) sensitized guinea-pigs caused inflammation, as indicated by increased vascular permeability. Histological changes after exposure to these compounds progressed with time form intense vasodilation to marginalization of granulocytes followed by interstitial migration of leukocytes. In vitro incubation of guinea-pig bladder tissue with substance P and ovalbumin stimulated release of prostaglandin D2 and leukotrienes. In vitro incubation of bladder tissue with capsaicin, OVA, prostaglandin D2, leukotriene C4, histamine, or calcium ionophore A-23587 all stimulated substance P release. These data suggest that bladder inflammation initiated by a variety of stimuli could lead to a cyclic pattern of release of inflammatory mediators and neuropeptides, which could result in amplification and persistence of cystitis after the inciting cause has subsided.