Purpose: To demonstrate the change in the expression of angiotensin II type 1 receptor (AT1) in the rat bladder with partial bladder outlet obstruction (P-BOO). Materials and Methods: Bladder specimens were obtained from 12-week-old Wistar female rats that were divided into two groups, a P-BOO group and a control group. The rats of the P-BOO group were divided into six groups: a sham-operated control group, 1 day postoperatively, 2 days postoperatively, 4 days postoperatively, 7 days postoperatively and 14 days postoperatively. The cystometric findings and immunohistochemical staining of the detrusor muscle with the AT1 antibody were compared in each group. Results: AT1 localized on the cell membrane of the detrusor smooth muscle and in cytoplasm of suburothelial myofibroblasts in the control rats. The expression of AT1 disappeared in the detrusor muscle and suburothelial myofibroblasts in P-BOO, but AT1 was highly expressed in urothelial cells 1 day after surgery. The expression of AT1 in urothelial cells gradually decreased with time after surgery. AT1 completely disappeared in urothelial cells 14 days after surgery. Conclusions: The present study demonstrated that the site of AT1 expression changes in response to the mechanical stress caused by P-BOO, and finally there was no expression of AT1 in rat bladder tissue following P-BOO. These data suggest the change in AT1 expression may play a role in bladder function.

Keywords:
Angiotensin II type 1 receptor, Bladder, Bladder outlet obstruction, Immunohistochemistry, Rat
1.
Peach MJ: Renin-angiotensin system: biochemistry and mechanisms of action. Physiol Rev 1977;57:313–370.
2.
Phillips MI, Speakman EA, Kimura B: Levels of angiotensin and molecular biology of the tissue renin angiotensin systems. Regul Pept 1993;43:1–20.
3.
Yamada S, Takeuchi C, Oyunzul L, et al: Bladder angiotensin-II receptors: characterization and alteration in bladder outlet obstruction. Eur Urol 2009;55:482–489.
4.
Mattiasson A, Uvelius B, et al: Changes in contractile properties in hypertrophic rat urinary bladder. J Urol 1982;128:1340–1342.
5.
Malmgren A, Sjögren C, Uvelius B, et al: Cystometrical evaluation of bladder instability in rats with infravesical outflow obstruction. J Urol 1987;137:1291–1294.
6.
Cannon TW, Damaser MS: Effects of anesthesia on cystometry and leak point pressure of the female rat. Life Sci 2001;69:1193–1202.
7.
Tanabe N, Ueno A, Tsujimoto G: Angiotensin II receptors in the rat urinary bladder smooth muscle: type 1 subtype receptors mediate contractile responses. J Urol 1993;150:1056–1059.
8.
Waldeck K, Lindberg BF, Persson K, et al: Characterization of angiotensin II formation in human isolated bladder by selective inhibitors of ACE and human chymase: a functional and biochemical study. Br J Pharmacol 1997;121:1081–1086.
9.
Lam DS, Dias LS, Moore KH, Burcher E: Angiotensin II in child urinary bladder: functional and autoradiographic studies. BJU Int 2000;86:494–501.
10.
Andersson KE, Hedlund H, Stahl M: Contractions induced by angiotensin I, angiotensin II and bradykinin in isolated smooth muscle from the human detrusor. Acta Physiol Scand 1992;145:253–259.
11.
Erspamer V, Ronzoni G, Falconieri Erspamer G: Effects of active peptides on the isolated muscle of the human urinary bladder. Invest Urol 1981;18:302–304.
12.
Saito M, Kondo A, Kato T, Miyake K: Response of the human urinary bladder to angiotensins: a comparison between neurogenic and control bladders. J Urol 1993;149:408–411.
13.
Dinh DT, Frauman AG, Somers GR, et al: Evidence for activation of the renin-angiotensin system in the human prostate: increased angiotensin II and reduced AT1 receptor expression in benign prostatic hyperplasia. J Pathol 2002;196:213–219.
© 2012 S. Karger AG, Basel
2012
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