IN-VITRO FUNCTIONAL-PROPERTIES OF THE RAT BLADDER REGENERATED BY THE BLADDER ACELLULAR MATRIX GRAFT

Purpose: To assess the response of rat urinary bladder regenerated by the homologous bladder acellular matrix graft (BAMG) to in vitro elect rical and pharmacologic stimuli. Materials and Methods: In Sprague-Daw ley rats, partial cystectomy (>50%) was performed, followed by BAMG au gmentation cystoplasty. After 4 months, organ bath studies of tissue s trips in 10 were used to compare the contractility of the BAMG regener ates and the corresponding host detrusor smooth muscle. Results:. The BAMG regenerates exhibited contractile activity to electrical field st imulation and a qualitatively identical pattern of response to muscari nic, purinergic, a-and p-adrenergic drug administration and nitric oxi de. At 4 months after surgery, the maximum forces of contraction of th e BAMG regenerates to carbachol stimulation amounted to close to 80% o f the host bladder response. With electrical field stimulation, they e qualed 44% and 62% of the host bladder response after 2.5 and 4 months , respectively. Histological and immunohistochemical studies confirmed the presence of receptors for neurotransmitters that these functional in vitro studies implied. Conclusions: The present study provides fur ther evidence that augmentation cystoplasty with the BAMG leads to fun ctional regeneration of the rat bladder detrusor smooth muscle.