Introduction and hypothesis: The objective of this study is to investigate the expression of calpain-1, calpain-2, and calpastatin in the human periurethral vaginal tissues and to show the potential link between calpain system and stress urinary incontinence (SUI).
Methods: The periurethral vaginal tissues of 39 women with SUI and 31 women without SUI were collected to detect the expressions of calpains and calpastatin by using semi-quantitative competitive reverse transcription-polymerase chain reaction and Western blotting.
Results: There were no significant differences on the expressions of calpain-1 at the levels of messenger RNA (mRNA) and protein in both groups (P > 0.05), but the patients with SUI had significantly higher levels of calpain-2 mRNA and protein than the control (P < 0.05); and the mRNA expressions of calpastatin in women with SUI were significantly higher than the control (P < 0.05), while the protein expressions were significantly lower when compared to the control (P < 0.01).
Conclusions: Overexpression of calpain-2 and low expression of calpastatin may involve in the pathological development of SUI.