| Stress urinary incontinence (stress urinary incontinence, SUI) is a common female disease,a large sample epidemiological survey showed12.5percent of women suffer for SUI, especially the middle-age and aged women a higher prevalence of about10%to27%, often associated with pelvic genital bulging or prolapse (Pelvic Organ Prolapse, POP), seriously affect the quality of life of patients. Female SUI is defined according to the International Continence Society (International Continence Society, ICS), abdominal pressure higher than the maximum urethral pressure without detrusor contraction and urine involuntary external urethral orifice overflow is because of that abdominal pressure increased, like more coughing, sneezing, erection and tiredness. The genesis mechanism about stress urinary incontinence is not clear. Clinical studies have shown that the SUI incidence of pelvic floor anatomical defects and functional disorders. In addition, the" integral theory "and "hammock hypothesis" about the pathogenesis of SUI have agreed by most experts and scholars, and the two theory emphasized the important role of the pelvic support organizations in the process of maintaining a controlled level of urinary. Among them, the pelvic floor nerve injury may be one of the pathogenesis of SUI. For SUI mechanism of nerve damage, the domestic and foreign research scholar at the focus on flesh report graph and nerve conduction speed, electrophysiology, and this research aims to establish effective SUI animal models. And based on this, we are research that through the observation of nerve fibers marker Protein gene product9.5(Protein gene product9.5, PGP9.5) and neural peptide neurotransmitter Neuropeptide Y (Neuropeptide Y, NPY) from the perspective of molecular biology in the SUI pelvic floor muscles and model genitourinary structure of the changes in the situation, and the structure and function of the barriers at the micro performance, and provide further evidence of for SUI nerve damage theory.Objective(1) A study simulated female stress urinary incontinence risk factors like birth trauma, dystocia, dense production, postmenopausal estrogen levels low, according to the test urine flow mechanics index and sneezing that the establishment of animal models of SUI feasibility and stability.(2) This experiment through the observation of stress urinary incontinence of rats pubococcygeus and the urogenital structure of the histological changes, and by exploring the protein gene product9.5(PGP9.5) and neuropeptide Y (NPY) Changes in the distribution of stress urinary incontinence pelvic floor denervation of the doctrine of search for further evidence. To further seek conservative treat SUI lay the foundation.Materials and Methods1MaterialExperimental animals The healthy adult Sprague-Dawley female rats altogether45provided by Zhengzhou University Experimental Animal Center, and weighing about180-220g, were randomly divided into experimental groups of25and20in the control group. Spraue-Dawley male rats5and weighs220-280g.2Method2.1SUI model establishment Pregnancy SD rats after postpartum through the two expansion of the vagina simulation of delivery damage. the damage caused by dense production, as well as by surgical ovariectomy mimic ovarian castration and menopause and, ultimately, a total of15cases of stress urinary incontinence rat model (after urinedynamic monitoring and sneezing test to determine Table1). Otherwise normal rats of20cases.2.2By the method of putting epidural catheter into the urethral, Through test the urine dynamic index biggest bladder capacity, abdominal leak point pressure, and sneezing test positive rate, to build a successful test whether the model.2.3The rats were killed, take SUI model rats and the normal rats’s pubococcygeus、 the anterior vaginal wall and urethra, pubococcygeus and the urogenital tract organization the pathological changes by HE staining; and immunohistochemical method of testing specimens of PGP9.5, expression of NPY.3Image and results analysisBy HE staining observation of pubococcygeus, the anterior vaginal wall and urethra form and muscle content, muscle fiber morphology. PGP9.5is widely distributed in the central and peripheral nervous system neurons, nerve fibers,which is can be a specific marker of nerve fibers and nerve bundles. Positive region of the immunohistochemical staining color is brown to tan. The nerve fibers of NPY immunoreactivity were mainly distributed around blood vessels and in The smooth muscles. The average gray value of positive indicators to express the staining intensity of the staining region to evaluate and analyze.4Statistic analysisBy SPSS13.0statistical analysis software for statistical analysis of measureme-nt data as mean±standard deviation (x±s); Between two groups of measurement data using matched-sample comparison group methodology. x2test were used for enumeration data. Inspection level α=0.05. Results1SUI model cases:The simulation of human childbirth injury, dystocia, dense production after menopause, low estrogen levels can successfully obtain stable animal model. Ml and leak point pressure values standard deviation (10.54±0.47vs.28.43±0.42) mmHg, the difference was statistically significant (t=24.139, P=0.001); the bladder capacity (1.38±0.11vs.2.13±0.85) ml, the difference was statistically significant (t=88.604, P=0.001). Sneezing lab testing was found only15model rats, sneezing reflection is positive, and the control group did not see sneezing reflection positive rats, the difference was statistically significant (x2=29.679, P=0.001).2The model group pubococcygeus and the anterior vaginal wall and urethra wall by HE staining with the respective control group:(1)In the control group pubococcygeus muscle fibers arranged in parallel, there is a proper clearance between muscle, Uneven coloring,and muscle fiber membrane integrity; model group pubococcygeus fiber remarkable atrophy, the arrangement sparse disorder, uneven coloring, visible muscle fiber go do the bending fracture and degeneration changes.(2) In control group, the anterior vaginal wall is seen epithelial layer and lamina propria microscopically, the lamina propria mainly is the connective tissue, which shows smooth muscle organization, small nerve tissue, small blood vessels and capillary structure. Lamina propria smooth muscle is bulky, a neat arrangement; The model group before vaginal wall lamina propria connective tissue arrangement sparse, smooth muscle more finely sparse, arrangement, disorder, muscle bunch of gap grows wider, muscle fiber appear rupture phenomenon, neural tissue content decrease.(3) The control group urethral smooth muscle is arranged in a circle, the fibroblast cells, collagen fibers and contains vascular and nerve structures are closely linked, collagen is pink material,which is arranged like a bunch of shape even wispy evenly; Model group urethral smooth muscle cells, collagen fibers arranged in sparse thinner, reduce the density, was the focal arrangement of beam with a small amount of blood vessels and nerves, and other ingredients.3By immunohistochemistry and image analysis:Pubococcygeus, the anterior vaginal wall and urethra wall, of PGP9.5and NPY expression, sections of PGP9.5and NPY immunohistochemical staining positive regional color was brown to brown.(1) The SUI model group compared with a control group, the PGP9.5in the SUI model group’Pubococcygeus muscles is lower expression (112.01±6.83vs.131.71±5.05), the difference was statistically significant(t=9.118, P=0.001). SUI end of muscle group of NPY low expression(131.71±3.42vs.145.05±7.32), the difference was statistically significant (t=8.292, P=0.001).(2) The vaginal mucosa at the front wall slice, visible vaginal mucosa of nerve fibers and inherent in small nerve bundle distribution, The SUI model group compared with a control group, the PGP9.5in the SUI model group is lower expression(119.97±6.95vs.134.09±5.25), the difference was statistically significant (t=7.349, P=0.001). The NPY in the SUI model group is lower expression113.08±5.96vs.140.43±4.88), the difference was statistically significant (t=18.321, P=0.001).(3) The Urinary tract mucous membrane cortex and inherent floor are inherent nerve fibers and small nerve bundle distribution, The SUI model group compared with a control group, the PGP9.5in the SUI model group is lower expression(123.68±4.58vs.139.98±4.90), the difference was statistically significant (t=6.990, P=0.001). The NPY in the SUI model group is lower expression(115.13±2.38vs.128.67±1.73), the difference was statistically significant (t=5.781, P=0.001).Conclusion(1) An analog of human pregnancy, birth injury, dystocia, dense production, as well as postmenopausal low estrogen levels can successfully obtain stable and effect-ve rat model of SUI.(2) Pelvic floor function and structure changes in the SUI model group, and the lower expression of the nerve fiber makers PGP9.5and NPY shows that neurogenic injury may be involved in the incidence of SUI.. |
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