Morphological analysis of the bladder wall in experimental interstitial cystitis/ bladder pain syndrome

The etiology of interstitial cystitis/bladder pain syndrome (IC/BPS) is still poorly understood. We used experimental animal models to analyze the disease pathophysiology. Histopathological characteristics may play an important role in predictive modeling of IC/BPS symptoms. We performed histological examination of the bladder mucosa in 4 experimental IC/BPS models. The experiment was performed on 37 female rabbits. We injected protamine sulfate into the bladder cavity (Group 1), or injected urine taken from the bladder of the animal into the bladder wall (Group 2), or injected 0.9 % NaCl solution into the bladder wall (Group 3), or injected nothing (Group 4). Fourteen days later, rabbits were euthanized using pentobarbital at a dose of 200 mg/kg. Then the animals were dissected with a transabdominal incision along the middle line with subsequent cystectomy, collection of biopsy specimens, and preparation of sections. Cell infiltration was assessed using the following scale: grade 0-no extravascular leukocytes and mast cells; grade 1-less than 20 leukocytes and mast cells; grade 2-20 to 45 leukocytes and mast cells; grade 3 - more than 45 leukocytes and mast cells. The scores of all 10 sections were added, divided by 30 (the maximum possible score), and multiplied by 100. Scores on leukocytes and mast cells for each bladder were the average of 3 studied sections. Leukocytes and mast cells were counted at ×200 magnification. Animals from Group 1 had the largest number of all leukocytes (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }