Different expression of calpains in the anterior vaginal wall of women with and without uterovaginal prolapse

OBJECTIVE: Tissue ischemia-hypoxia can activate the calpain proteolytic system. Mechanical trauma to the upper vaginal wall and pelvic floor could compromise vascular perfusion and could also result in calpain expression. The aims of this investigation were to assess the expression messenger RNA and proteins for m-calpain and μ-calpain in the vaginal walls of women with and without uterovaginal prolapse. METHODS: The anterior vaginal walls of 22 women with and without uterovaginal prolpase were evaluated using a reverse transcription polymerase chain reaction and western blotting for detecting calpain expression. RESULTS: The number of messenger RNA transcripts of m- and μ-calpain was significantly less in women with uterovaginal prolapse than in women without uterovaginal prolapse (two of 11 and zero of 11 versus eight of 11 and five of 11, P < .05). All women had m-calpain protein expression in the anterior vaginal wall. However, the concentration of m-calpain protein was less, but not significantly different, in women with uterovaginal prolapse than in the women without uterovaginal prolapse (0.386 ± 0.018 versus 0.439 ± 0.011 optical density/mm2, P > .05). None of the women with uterovaginal prolapse had expression of μ-calpain mRNA or protein (zero of 11). Expression of protein of calpains in the anterior vaginal wall is not consistent with mRNA transcripts. CONCLUSION: Calpain expression may be compromised in the anterior vaginal wall of women with uterovaginal prolapse who have abnormal histologic changes in the vaginal connective tissues or have anterior vaginal laxity.