| ObjectivePresent work aimed to observe the relativity of expression of decorinand content of type â…¢collagen in paraurethral connective tissue, todetect biochemical changes in paraurethral connective tissue, and toexplore whether the alteration in collagen concentration and decorinexpression could contribute to stress urinary incontinence(SUI) andpelvic organ prolapse(POP).MethodsTransvaginal biopsies were obtained from paraurethral connectivetissue in SUI, POP, and comparable control. Seventy-three womenparticipated in the study. They were divided into 6 groups as follows:11 premenopausal patients with SUI (group 1), 8 premenopausal patientswith POP(group 2), 12 premenopausal patients with neither SUI norPOP(group 3), 9 postmenopausal patients with SUI (group 4), 16postmenopausal patients with POP (group 5), and 17 postmenopausalpatients with neither SUI nor POP(group 6).In the specimens, theconcentration of type â…¢collagen was determined by immunohistochemicaltechnique, followed by electrophoretic separation and quantification.Reverse transcription-polymerase chain reaction (RT-PCR) was used toverify the mRNA level of decorin.ResultsType â…¢collagen was significantly reduced (p < 0.01)in bothpremenopausal and postmenopausal patients with SUI (including group 1 and4), compared to the control group (including group 3 and 6). The meanconcentration of type â…¢collagen was 32% lower in premenopausal womenwith SUI, 35% lower in postmenopausal women with SUI, compared tocorresponding controls. We found that the expression of decorin wassignificantly high(p<0.01) in both premenopausal(72%) andpostmenopausal(65%) patients with SUI, and they had the high relativityto the variability of type â…¢collagen. The correlation coefficients were-0.626 (premenopausal) and -0.639 (postmenopausal) respectively. Type â…¢collagen was significantly reduced (p < 0.01) in bothpremenopausal and postmenopausal patients with POP (including group 2 and5), compared to control patients (including group 3 and 6). The meanconcentration of type â…¢collagen was 21% lower in premenopausal womenwith SUI, 29% lower in postmenopausal women with POP, compared tocorresponding controls. When compared to corresponding control group,both premenopausal and postmenopausal patients with POP(including group2 and 5) had a similar(p>0.05) expression of decorin in paraurethralconnective tissue biopsies. As to age,parity and menopausal time, we foundthat postmenopausal patients with POP (group 5) had significantly olderage, more parity and longer postmenopausal time(p<0.05),when comparedto postmenopausal patients with SUI(group 4) and postmenopausal controlpatients (group 6).Conclusion In this study, we found that both premenopausal and postmenopausalwomen with SUI had a significant decreased level of type â…¢collagen inparaurethral connective tissue and that the expression of decorin wassignificantly elevated. We also found a strong correlation between thequantity of collagen type â…¢and the expression of decorin inparaurethral connective tissue, suggesting that collagen metabolism wasaltered by decorin. A high level of mRNA for decorin in the SUI groupindicated that the differences could be related to an altered collagenmetabolism. These alterations should result in a less flexible form ofextracellular matrix, suggesting a connective tissue with impairedmechanical function. Those tissues probably were less elastic and morelikely to break, which suggested that decorin might be involved in thepathogenesis of SUI. In this study, we also found that women with POP had a significantlylow type â…¢collagen in paraurethral connective tissue, suggesting POPwas probably associated with a change in collagen metabolism, resultingin a decreased concentration of collagen. But there was no change ofdecorin observed in the women with POP, neither in premenopausal nor inpostmenopausal POP patients, suggesting that decorin had very little orno effect on collagen metabolism in paraurethral connective tissue inpatients with POP. Meantime, we found that postmenopausal patients withPOP (group 5) had significantly older age, more parity and longerpostmenopausal time,when compared to patients in group 4 and 6, and thatpostmenopausal women with or without POP had a similar expression ofdecorin in paraurehtral connective tissue. Based on these investigations,we reached the conclusion that the collagen metabolism in paraurethralconnective tissue in postmenopausal patients with POP might be modulatedby aging process, higher parity,previous pelvic trauma and reproductivehormones, which suggested that age,parity and the level of estrogen mightbe involved in the pathogenesis of POP. |
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