| Objective:The experiment is intended to build the rabbit animal model of bladder outlet partial obstruction and observe the changing of structure remodeling of bladder wall and compliance after obstruction. We intend to study the possible mechanism and the key point of its pathophysiology. The specific aim of the study is to determine whether doxazosin treatment on rabbits affect blood flow to the bladder and reduces the level of bladder dysfunction induced by partial outlet obstruction. We look forward to finding appropriate intervention point to slow down or relief the fibrosis of the bladder and low compliance after BOO.Methods:36male New Zealand White rabbits were divided randomly into4groups. Among of them,9rabbits were contrast group A;9rabbits were operated for BOO as group B;9rabbits were operated and received doxazosin as group C; group D were contrast and received doxazosin including9rabbits. Group B and C underwent partial outlet obstruction creation by standard methods. The contrast groups were done only dissection without ligation. We did the urinary dynamics test for4groups5weeks after operation. After test, we obtained the bladder specimen, HE staining, light microscope observing structure, smooth muscle and fibrous connective tissue change.ResultsThe bladders of BOO animal model demonstrated typical post-obstruction alterations after partial ligation of the bladder neck. The weight increased significantly in obstruction group(16.9±4.4)g, obstruction and received doxazosin group (8.9±5.9)as compared with that in control group(2.7±0.5)g, P<0.01.The bladder leak point pressures were significantly greater in obstructed group, P<0.01, doxazosin can significantly reduce the bladder leak point pressure, P<0.01. The study of light microscope certificated hypertrophia and hyperplasia of the detrusor after bladder outlet obstruction. The collagen was notable increased between the muscle bundles.Conclusions(1) BOO animal model established by partial ligation of the bladder neck of adult male rabbits is simple, stable and suitable for studies of bladder outlet obstruction.(2) The structure and function of the bladder was significantly changed5weeks after operation:the weight and maximum volume of bladder in obstructed group was significantly increased. Light microscope observed that smooth muscle hypertrophied and fibrous connective tissue increased in smooth muscle compartments.(3) Doxazosin can decrease the degree of weight and volume increasing, increase the blood flow to bladder muscles of obstructed rabbits, reduce the bladder leak point pressure and protect bladder function. |
