Extracellular matrix gene responses in a novel ex vivo model of bladder stretch injury.

Purpose: Congenital bladder outlet obstruction from either mechanical or functional causes often results in clinical bladder fibrosis. We tested the hypothesis that early molecular changes relevant to fibrosis occur in response to stretch injury of the bladder wall and that specific extracellular matrix receptors mediate some of these responses. Furthermore, we introduce a novel ex vivo model of bladder injury which has advantages over previously described in vivo bladder outlet obstruction models by uniquely interrogating molecular responses to bladder distention.Materials and Methods: The bladders of Sprague Dawley rats were hydrodistended transurethrally, the ureters and bladder neck were ligated, and the whole bladder was excised and incubated in culture medium in the distended state. At fixed time-points control and stretch bladders were snap frozen, RNA was extracted, and semiquantitative reverse transcription polymerase chain reaction for collagens I, III and XII, and RHAMM (receptor for hyaluronic...