IN-VITRO PASSIVE SENSITIZATION OF GUINEA-PIG, RHESUS-MONKEY AND HUMANBLADDERS AS A MODEL OF NONINFECTIOUS CYSTITIS

Studies of human bladder inflammation have been limited to examination of urine bladder biopsy, or examination of autopsy material. We have developed an in vitro bladder passive sensitization technique which ca n measure type I responses of isolated human bladder tissue. We have c ompared these results using human tissue to those obtained with bladde r tissue from guinea pigs and Rhesus monkeys. In our studies, bladder tissue was passively sensitized in vitro for 20 hours with immunoglobu lin-containing serum. Subsequent antigen challenge of the passively se nsitized tissue resulted in a time-dependent contraction that was acco mpanied by tissue histamine release. Contractions of guinea pig, monke y and human bladder tissue reached 79%, 100% and 78% of the maximal co ntraction induced by potassium chloride. In contrast, adjacent strips of unsensitized tissue had no detectable response to antigen challenge . The responses were reduced in the presence of histamine H-1 receptor blockade with pyrilamine and abolished in the presence of a concomita nt blockade of leukotriene synthesis with nordihydroguaiaretic acid (N DGA). Blockade of cyclooxygenase activity with indomethacin increased the contraction of the sensitized guinea pig bladder in response to an tigen challenge. These findings demonstrate that in vitro passive sens itization of human bladder tissue can be used to investigate basic mec hanisms of noninfectious bladder inflammation in humans.