Study On The Changes In Expression Of Desmin And Dystrophin Of Pregnancy And Childbirth In Rats And Their Significance

Objective:1To study influence of pregnance and childbirth on the distribution and theexpression of desmin and dystrophin in pelvic floor muscle derived from rats.2To investigate the effects of pregnance and childbirth on the SkeletalMuscular Cytoskeleton.3To investigate the effects of pregnance and childbirth on the pelvic floordysfunction.Methods:1The subjects: Forty-five female virgin Wistar rats were provided by HebeiMedical University Experimental Animal Center, and weighing about180~220g, were randomly divided into experimental groups of30and15inthe control group. Wistar male rats10and weighs220~250g.The experimentalgroups of30female virgin Wistar rats got pregnant and childbirth, wererandomly divided into vaginal childbirth group and6days after childbirthgroup.2Specimen: Under anesthesia, the rats were dissected down to the level of thepelvis to expose the levator ani muscle. The specimens were taken from thelevator ani muscle of each group of rats quickly, and weighing about100mg.The levator ani muscle was divided into two pieces, washing and absorbing. Apiece of specimens preserved immediately-80℃was used for Real-timefluorescence quantitative PCR. Another piece of specimens preserved4%fixed in paraformaldehyde solution24h was used for Immunohistochemicalstaining.3The changes of the levator ani muscle were observed by HE staining; andimmunohistochemical method of testing specimens of the expressions of Desmin and Dystrophin.4The expression of mRNA of Desmin and Dystrophin in levator ani musclewere measured by Real-time fluorescence quantitative PCR. All the result datawere described as mean±standard deviation（±S）. SPSS16.0software wasused for statistical analysis. If P＜0.05, it is believed that there is statisticallysignificant.Results:1HE staining results: The sections of levator ani muscle on each group wereobserved by HE staining. The muscle fibers on the control group connectedclosely around multiple nucleus which closed to the endomysium surface, thestructures of collagen fibers, fibroblasts, blood vessels and nerve werecontained among the muscle beams, no degeneration necrosis performance ofthe muscle fibers. Comparing with the control group, the muscle fibers of thevaginal childbirth group were relatively sparse, slightly disordered, there werepartially visible to the cross-sectional area of the muscle cells in different sizes,shrinking and mast cells and the necrosis of the muscle fibers; The musclefibers of6days after childbirth group arranged more closely than the vaginalchildbirth group, no degeneration necrosis performance of the muscle fibers.2Immunohistochemistry results: The sections of Desmin and Dystrophinimmunohistochemical staining positive regional color are brown on thecytoplasm and the sarcolemma of muscle fibers separately. The Desmin andDystrophin in the vaginal childbirth group’s levator ani muscle is lowerexpression than the non-pregnant group and the6days after childbirth group,the difference was statistically significant(P＜0.05), while there was nostatistically significant difference between the non-pregnant group and the6days after childbirth group.3Real-time fluorescence quantitative PCR results: Compared with thenon-pregnant group and the6days after childbirth group, the mRNAexpression of Desmin and Dystrophin in levator ani muscle of the vaginalchildbirth group decreased. The difference was statistically significant(P＜0.05), there was no statistically significant difference between the non-pregnant group and the6days after childbirth group.Conclusions：1The morphology of pelvic floor muscle fibers changed in pregnancy andchildbirth, and the expression of Desmin and Dystrophin decreased. Thehigher expression of Desmin and Dystrophin after childbirth showed theregeneration of pelvic floor muscle fibers.2The changes of skeletal muscular cytoskeleton in pelvic floor are anadaptive response to pregnancy and childbirth.3Pregnancy and childbirth play some role in the pathogenic mechanism ofPFD. The Desmin and Dystrophin of pregnancy and childbirth in rats arereducing. The factor may play an important role in the incidence of PFD.