Muscarinic and purinergic receptor expression in the urothelium of rats with detrusor overactivity induced by bladder outlet obstruction.
OBJECTIVE
To investigate the expression of muscarinic and purinergic receptors in rat urothelium, and changes in their distribution and expression following detrusor overactivity induced by bladder outlet obstruction (BOO).


METHODS
Thirty Sprague-Dawley rats were divided into control (10) and BOO groups (20). Partial BOO was induced for 3 weeks and the rats assessed by cystometrography. A portion of the bladder was stained using immunofluorescence for M(2) and M(3) muscarinic receptors, and P2X(3) purinergic receptors. The remainder was dissected into bladder urothelium and the smooth muscle layer, and the expression of the receptor proteins analysed by Western blotting.


RESULTS
Cystometrography showed a significant decrease in contraction interval and increase in contraction pressure in the BOO group. On immunofluorescence staining, muscarinic and purinergic receptors were localized in both the urothelium and the muscle layer. Immunoreactivity of M(2) and M(3) muscarinic receptors was greater in the urothelium of the BOO group than in the control group; there was a smaller increase in P2X(3) immunoreactivity. On Western blotting, the expression of M(2), M(3) and P2X(3) receptors was increased in the urothelium of the BOO group, and there was increased M(3) receptor expression in the muscle layer of the BOO group.


CONCLUSIONS
There were detectable changes in muscarinic and purinergic receptors with bladder overactivity induced by BOO. Our results suggest that changes in urothelium receptor expression could have a role in mediating the afferent sensory responses in the urinary bladder.
Kim
Joon Chul
JC
Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea. kjc@catholic.ac.kr
Yoo
Jae Suk
JS
Park
Eun Young
EY
Hong
Sung Hoo
SH
Seo
Seong Il
SI
Hwang
Tae-Kon
TK
D000818:Animals; D015153:Blotting, Western; D005455:Fluorescent Antibody Technique; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011976:Receptors, Muscarinic / Q000378:metabolism*; D011983:Receptors, Purinergic / Q000378:metabolism*; D001743:Urinary Bladder / Q000473:pathology*; D001748:Urinary Bladder Neck Obstruction / Q000150:complications / Q000473:pathology*; D053201:Urinary Bladder, Overactive / Q000209:etiology / Q000473:pathology*; D019459:Urothelium / Q000473:pathology
D011976:Receptors, Muscarinic; D011983:Receptors, Purinergic