Incontinence Research Today is a free monthly online journal that collates and summarizes the latest research about Incontinence, including details on urinary incontinence, bladder control, treatment, causes.

Is alpha2-macroglobulin important in female stress urinary incontinence?

Wen Y, Man WC, Sokol ER, Polan ML, Chen BH

Department of Obstetrics and Gynecology, Stanford University School of Medicine, 300 Pasteur Drive, H333 Stanford, CA 94305, USA. yanwen@stanford.edu

BACKGROUND: Loss of mechanical stability of the urethra and bladder is thought to be important in the development of stress urinary incontinence (SUI). The vaginal wall is the main supporting tissue for pelvic organs and changes in components of supporting tissues are known to be involved in the pathophysiology of SUI. METHODS: We evaluated changes in expression of alpha2-macroglobulin (alpha2-M), a protease inhibitor, in vaginal wall tissues from premenopausal women (aged 42-45 years) with SUI (n = 28) compared with menstrual cycle-matched continent women (controls, n = 29). The distribution of alpha2-M in vaginal wall tissues and fibroblasts was analysed by immunohistochemistry and immunofluorescence. Expression levels of alpha2-M mRNA and protein was determined by relative real-time quantitative PCR and enzyme-linked immunosorbent assay, respectively. Protease inhibition was measured to assess bioactivity. RESULTS: Vaginal wall tissues do express alpha2-M. Expression of alpha2-M mRNA and protein was significantly higher in tissues from controls compared to women with SUI in both proliferative and secretory phases (P < 0.05). Protease inhibitory activity of alpha2-M was significantly higher in tissues from controls compared to women with SUI in the secretory phase (P < 0.05), but we found no difference in the proliferative phase between groups. alpha2-M protein level was lower in the proliferative phase than the secretory phase in both controls and SUI patients, while for alpha2-M mRNA this was found only in controls. CONCLUSIONS: Decreased expression of alpha2-M mRNA and protein and protease inhibitory activity in the vaginal wall tissues of women with SUI may contribute to the development of SUI.

Published 17 January 2008 in Hum Reprod, 23(2): 387-93.
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