Mechanism Study Of Overactive Bladder Following Chronic Cervicitis

Background and objectives: Overactive bladder(OAB) is defined as urgency,with or without urinary incontinence usually with frequency and nocturia.OAB could show detrusor overactivity(DO) during urodynamics study.This term is as a symptom-based definition,to replace the urodynamics-based definition of'detrusor overactivity'. The incidence of OAB is high, The urological institute of Peking university carried out an epidemiological survey indicated that the incidence of OAB in females older then 18 years old was 40.4%. Although many antibiotics have been adoptd to treat and prevent in the last years, its morbidity and relapsed rate haven't been lower obviously, and influences a part of the adult female's daily life seriously. Currently the cause of disease hypotheses are a lot of, but there are also so many controversies, which lacks some experimental studys to clarify the concrete mechanism of the outbreak.Thus, further study on some aspects would be still needed.Now, many scholars have found there are some neural reflex existing mutual viscera organs and between viscera organs and some part in the body. A viscera organ or some part of the body stimulation could affect other organs's function related to it. There are reports of this neural reflex on urinary bladder, too.OAB appears to prostate diseases in male,but what in femals?The sexual life of married female is frequent,which stimulates the cervix greatly and induces the gynopathic morbidity present up-trend.Chronic gynecological inflammation,such as vaginitis, cervicitis, pelvic inflammation and so on, may result in a urinary bladder dysfunctions through the direct extension or throuth the lymphoid etc.paths,which has been already caused the value of the clinical doctors gradually.The majority of innervation in female genital tract are at cervix .The abnormal bladder functions was frequent reason of the voiding dysfunction, and can voiding dysfunction associated with chronic cervicitis be caused by a possible neural reflex between the cervix and urinary bladder? To our best knowledge, there are few reports concerning this,so the interesting hypothesis is worthy of being tested. This study will confirm the association between OAB and the chronic cervicitis and suggest a potential therapy for voiding dysfunction of chronic cervicitis through neuromodulational.Methods:The neural reflex between the cervix and urinary bladder was studied by physiological, neuroanatomical and functional approaches in female adult SD rats, and then the neural mechanism of the urinary bladder disfunction induced by chronic cervitis was proposed.1. The functional changes of urinary bladder induced nocuous stimulus to the cervix were studied by filling cystometry performed before and after building the cervicitis model with 25% phenol mucilage. The 25% phenol mucilage was replaced by 0.9% saline in control group.2. The bladder myoelectrical activities were simultaneously recorded when the cervix was electrically stimulated. The role of the brain and spinal cord in the neural reflex and reflex pathway were approached by the lidocaine blocking the neural conducting in cervix, executing the animals, transecting the cervical cord, cutting and resecting the sympathetic nerve stem in lumbar and cutting the parasympathetic nerve in lumbosacral area respectively.3. With the retrograde fluorescent double labeling method, fluorescein labeling condition of dorsal root ganglia(DRG) cells in lumbosacral area and axon reflex association was observed after the Propidium Iodide(PI) injected into the cervix and the Bisbenzimide(Bb) injected into the wall of urinary bladder respectively.Results1. In comparison with pre-stimulation, the nocuous stimulation to the cervix caused by 25% phenol mucilage made basic pressure and pre-micturition pressure considerably increased (p<0.01), bladder volume , micturition pressure and bladder compliance significantly lowered (p<0.01), and 66.67% rats'urinary baldder occurred instable contractions in filling. In control group, those urodynamic parameters were not significantly changed(p>0.05). These results indicated that the nocuous stimulus to the cervix could cause the bladder functions changed in rats and provided the functional proofs for the abnormal bladder functions induced by chronic cervicitis. 2. The stable myoelectrical wave could be recorded in the bladder wall when the cervix was stimulated by the electricity in rats. The waveform has shapes typical of slow wave, and the latent period and amplitude of wave were19.34±2.13ms and 773.62±281.33uv respectively. This indicated there was a association between cervix and urinary bladder.3. The latent period and amplitude of myoelectrical wave of urinary bladder was gradually extended and reduced respectively at 2min,5min and 10min after blocking the excitatory conduction of nerve in the cervix with the lidocaine, which are statistically significant (p<0.01)in comparison with those before blocking. The myoelectrical wave of urinary bladder disappeared after executing the animals by the excess anesthetic. This indicated that the wave was not the electrical wave diffusion from the cervix, but it's a neural reflex between the cervix and urinary bladder.4. The latent period and amplitude of myoelectrical wave of urinary bladder were not significantly changed after transecting the cervical cord. They were extended and reduced respectively after destroying the sympathetic nerve stem in homonymy T13～L5, the change was very significantly different comparing with pre-destroying(P<0.01). The myoelectrical wave of urinary bladder almost disappeared after cutting the parasympathetic nerves in homonymy L6～S3. All these had indicated that the parasympathetic central nervous system(CNS) in lumbosacral area played a key role in the cervix-urinary bladder neural reflex while the role of the sympathetic CNS in lumbar was minor, and the CNS in brain seldom influenced the neural reflex.5. Many fluorescent single labeled cells and double labeled cells were found in the L1～L2 and L6～S2 DRG, and the percentage of fluorescent double labeled cells was10.7±2.9%. The fluorescent double labeled cells were mainly the small neural cells in the L1～L2 and L6～S2. All these indicated that the DRG cells in lumbosacral area dichotomized to the cervix and urinary bladder and it could be one of reflex paths between cervix and urinary bladder, which provided the proofs of morphology and neuroanatomy for the neural mechanism of the abnormal bladder functions induced by chronic cervicitis.Conclusions and prospects:1. This study had confirmed the chronic cervicitis could cause the bladder functions changed in rats, and the change was a kind of reason of voiding dysfunction in clinic.The chronic cervictis could play some parts in the occurance of OAB.2. It was mediated by the neural reflex between the cervix and urinary bladder that the nocuous stimulus to the cervix could cause the bladder functions changed in rats, and the main mechanism was the viscero-viscer reflex of DRG cells in lumbosacral area of spinal cord.3. The viscero-viscer reflex between cervix and bladder could play a part in the occurance of OAB.This study may reveal the path hypothesis of the neural reflex: the excitation conducted to spinal cord mainly by the parasympathetic nerve afferent fibers after the cervix subjected to nocuous stimulus, via the viscero-viscer reflex of DRG cells in lumbosacral area of spinal cord, leading to antidromic activation of vesical afferent fibers , and resulting in bladder functions changed. The findings of this study suggest a potential therapy for voiding dysfunction of chronic cervicitis through neuromodula-tional, but another paths and mechanisms of the cervix-urinury bladder reflex was the emphasis in sequential studies.More attention shuold be payed to the treatment of the Gynecological disease when we treat the OAB in clinic.