Aims: To demonstrate changes in the number of suburothelial myofibroblasts in the rat bladder due to chronic urinary retention (CUR). Methods: Bladder specimens were obtained from 12-week-old Wistar female rats that were divided into two groups: a CUR group and a sham-operated group. In the CUR rats, the urethra was intubated with a polyethylene catheter, and a double 4-0 silk ligature was placed around the proximal urethra, after which the catheter was removed. After 8 weeks, the cystometric findings and immunohistochemical staining of the suburothelial myofibroblasts were compared between the groups. Results: The bladder weight of the control rats was 0.20 ± 0.01 g and that of CUR rats 1.6 ± 0.4 g. The bladder capacity of the control rats was 0.5 ± 0.3 ml and that of the CUR rats 12.9 ± 3.1 ml. The number of suburothelial myofibroblasts of the control rats was 417 ± 123 and that of the CUR rats 44 ± 42. The number of suburothelial myofibroblasts in the CUR rats was significantly less than that observed in the sham-operated rats (p < 0.01). Conclusions: In this study, we demonstrated that mechanical stress over a long period on the bladder wall can decrease the number of suburothelial myofibroblasts. The reduced expression of suburothelial myofibroblasts may be related to prolongation of the micturition interval by CUR.

Wu C, Sui GP, Fry CH: Purinergic regulation of guinea pig suburothelial myofibroblasts. J Physiol 2004;559:231-243.
Yamaguchi O: Antimuscarinics and overactive bladder: other mechanism of action. Neurourol Urodyn 2009;29:112-115.
Fry CH, Ikeda Y, Harvey R, Wu C, Sui GP: Control of bladder function by peripheral nerves: avenues for novel drug targets. Urology 2004;63(3 suppl 1):24-31.
Tobu S, Noguchi M, Hatada T, Mori K, Matsuo M, Sakai H: Upregulation of angiotensin II receptor and connexin 43 in increased suburothelial myofibroblasts in the rat inflammatory bladder. Low Urin Tract Symptoms 2013;5:90-95.
Kim SO, Oh BS, Chang IY, Song SH, Ahn K, Hwang EC, Oh KJ, Kwon D, Park K: Distribution of interstitial cells of Cajal and expression of nitric oxide synthase after experimental bladder outlet obstruction in a rat model of bladder overactivity. Neurourol Urodyn 2011;30:1639-1645.
Mattiasson A, Uvelius B: Changes in contractile properties in hypertrophic rat urinary bladder. J Urol 1982;128:1340-1342.
Malmgren A, Sjögren C, Uvelius B, Mattiasson A, Andersson KE, Andersson PO: Cystometric evaluation of bladder instability in rats with infravesical outflow obstruction. J Urol 1987;137:1291-1294.
Cannon TW, Damaser MS: Effects of anesthesia on cystometry and leak point pressure of the female rat. Life Sci 2001;69:1193-1202.
Tobu S, Noguchi M, Hatada T, Mori K, Matsuo M, Sakai H: Changes in angiotensin II type 1 receptor expression in the rat bladder by bladder outlet obstruction. Urol Int 2012;89:241-245.
Yamada S, Takeuchi C, Oyunzul L, Ito Y: Bladder angiotensin-II receptors: characterization and alteration in bladder outlet obstruction. Eur Urol 2009;55:482-489.
Dinh DT, Frauman AG, Somers GR, Ohishi M, Zhou J, Casley DJ, Johnston CI, Fabiani ME: Evidence for activation of the renin-angiotensin system in the human prostate: increased angiotensin II and reduced AT(1) receptor expression in benign prostatic hyperplasia. J Pathol 2002;196:213-219.
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