Altered Expressions of Calcium-Activated Potassium Channel and Connexin in Bladder Mucosae of Stress Urinary Incontinence Patients with Overactive Bladder Symptoms / 대한비뇨기과학회지

ABSTRACT

PURPOSE: The aim of this study was to examine how the mRNA and protein levels of calcium activated Kchannel (K(Ca)) and connexin (Cx) change in association with overactive bladder in the bladder mucosae of stress urinary incontinence (SUI) patients. MATERIALS AND METHODS: Twenty SUI patients were included in our study. Bladder mucosae were obtained, with using cold cup biopsy forceps, from the patients suffering with genuine stress urinary incontinence (group 1, n=7), from the patients suffering with SUI along with urgency and frequency (group 2, n=6), and from the patients suffering with mixed incontinence (group 3, n=7). RESULTS: The mRNA transcripts of type 2 (SK2) and type 3 (SK3) small conductance K(Ca), Cx26, and Cx43 were highly expressed in the bladder mucosa. The message of large conductance K(Ca)(BK) was significantly decreased in group 3 compared with that in the controls. The SK2 and Cx26 messages in group 3 were also lower than those in groups 1 and 2. In the presence of urge incontinence, the BK and SK2 protein levels were decreased and the Cx26 protein expression was significantly increased in the bladder mucosa of the SUI patients. In contrast, there were no significant differences in the mRNA and protein levels of K(Ca)s and Cxs between groups 1 and group 2. CONCLUSIONS: Downregulation of both BK and SK2 and upregulation of Cx26 in the bladder mucosa of MI patients may contribute to the alterations of urothelial instability, and this correlate with the symptom severity of bladder instability in SUI patients.