The Effects Of Pregnancy And Childbirth Of Rat Levator Ani Muscle Cytoskeleton

Objective:1To research the influence on rat levator ani muscle cytoskeletal proteinα-actin, tubulin, synemin content change and mRNA expression ofpregnancy and childbirth.2To explore the relationship between pregnancy, childbirth and thecytoskeleton.3To probe the role of levator ani muscle cytoskeletal change caused bypregnancy and childbirth in the pathogenesis of the female pelvic floordysfunction.Methods:1Object: To select the healthy Wistar rats of childbearing age, take20unmated females as the non-pregnancy group, then take60pregnant rats todivide into three groups, late pregnancy group, postpartum six hours groupand postpartum six days group randomly, each group have20rats. The ratsof each group are put to death timely to take the levator ani muscle afteradaptive feeding.(Supplied by the Department of Laboratory Animal, HebeiMedical University)2Materials: There are no significant differences in species, nest, age, weight,nutritional status and food intake and so on of rats supplied by theDepartment of Laboratory Animal, Hebei Medical University. Thespecimens of the levator ani muscle, about the size of0.5cm×0.5cm×0.5cm, fixed in10%neutral formal solution and stored in liquid nitrogenrespectively.3Using immunohistochemistry(IHC, SP method) and real-time fluorescencequantitative PCR (RT-PCR) to detect the α-actin, tubulin and syneminexpression in the rats levator ani muscle cells of non-pregnancy group, late pregnancy group, postpartum six hours group and postpartum six daysgroup.4Using SPSS13.0statistical software package for statistical analysis of theexperimental data. P <0.05is considered statistically significant.Results:1IHC results: The expression of α-actin, tubulin, synemin are detected in therats levator ani muscle cells in the group of non-pregnancy, late pregnancy,postpartum six hours, six days postpartum. The expression level of α-actin isstatistically significant in the four group of non-pregnancy, late pregnancy,postpartum six hours, postpartum six days (P<0.05). The expression level oftubulin is statistically significant in the four group of non-pregnancy, latepregnancy, postpartum six hours, postpartum six days (P<0.05). Theexpression level of synemin is statistically significant in the four group ofnon-pregnancy, late pregnancy, postpartum six hours, postpartum sixdays(P<0.05). With pregnancy, childbirth and postpartum recovery process,expression of α-actin and synemin increases after decreases, expression oftubulin decreases after increases. But between the two groups are found, theexpression of α-actin in the non-pregnancy group and late pregnancygroup(P=0.084), tubulin in late pregnancy group and the postpartum sixdays group (P=0.836) are no significant difference. Remaining comparisonsbetween the two groups are significant differences.2RT-PCR results: The the expression of α-actin mRNA for late pregnancygroup, postpartum six hours group and postpartum six days group (0.975±0.010,0.726±0.021,0.906±0.113) comparing with non-pregnancy group(1.000±0.000) increases after decreases, except non-pregnancy group andlate pregnancy group, remaining comparisons between the two groups aresignificant differences, P<0.05. The the expression of tubulin mRNA for latepregnancy group, postpartum six hours group and postpartum six days group(1.652±0.085,5.905±0.132,3.059±0.177) comparing with non-pregnancygroup (1.000±0.000) decreases after increases, comparisons between thetwo groups are significant differences, P<0.05. The the expression of synemin mRNA for late pregnancy group, postpartum six hours group andpostpartum six days group (0.865±0.026,0.532±0.042,0.735±0.014)comparing with non-pregnancy group (1.000±0.000) increases afterdecreases, comparisons between the two groups are significant differences,P<0.05.Conclusions:1The expression of rat α-actin, synemin mRNA and protein levels caused bypregnancy and childbirth decreases firstly, but after the postpartum recovery,it increases, the expression of tubulin mRNA and protein levels is increasedfirst, but it drops after postpartum recovery.2Pelvic floor muscle cell cytoskeleton changes are adaptive response tomuscle cells stretch caused by pregnancy and childbirth.3Pregnancy and childbirth play a role in the pathogenesis of pelvic floordysfunction.