Increased expression of neuregulin 1 in the urothelium of rat bladder with partial bladder outlet obstruction

BACKGROUND: This study determined whether changes in the expression of neuregulin (NRG) 1, erbB2 tyrosine kinase (ErbB2) and the M2 muscarinic receptor in the urothelium and detrusor muscle of the rat bladder were associated with partial bladder outlet obstruction (PBOO). METHODS: Male Sprague-Dawley rats (body weight 250–300 g) were used and subdivided into control (n = 10) and PBOO groups (n = 20). PBOO was induced for 21 days, and the expression of NRG1, ErbB2 and M2 muscarinic receptor mRNA and protein was evaluated using reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting, respectively. RESULTS: In the urothelium of rat bladder samples, protein expression and mRNA expression of NRG1, ErbB2 and M2 muscarinic receptor were significantly increased in the PBOO group compared to the control group (p < 0.05). Only mRNA expression levels of NRG1/ ErbB2 were higher in the detrusor muscle of the PBOO group compared to the control group (p < 0.05). CONCLUSIONS: Our study demonstrated remarkable changes in the expression of NRG1/ErbB2 receptor mRNA and protein in the urothelium and muscle layer. These results suggest that NRG1 overexpression plays some kind of role against the PBOO-induced upregulated muscarinic receptors in detrusor overactivity.