Altered expession of interstitial cells of cajal in neuropathic bladder due to experimental myelomeningocele model of rat fetuses

Introduction and aim: Myelomeningocele is a non-lethal neural tube defect that affects central and peripheral nervous system. Prevalence of myelomeningocele is one case per 2000 live births. It is the most common reason of neurogenic bladder dysfunction in children. Although neurogenic bladder dysfunction is related with bladder innervation, there are some changes seen in smooth muscle and neural cells of the bladder.Interstitial cells of Cajal (ICC) are pacemaker cells found in human peristaltic organs which were first described in the gastrointestinal tract. It is advocated that ICC are originating from the precursors of the smooth muscle cells.Recently C-kit positive ICC has been shown in guinea pig bladder. Interstitial cells of Cajal had been shown decreased in the bladder of megacystis-microcolon intestinal hypoperistalsis syndrome patients when compared with normal human bladders. There is no data in the literature about the number and localization of ICC in neurogenic bladder.Material and method: Dams were gavage fed all-trans retinoic aside at embryologic day 10 (E 10). This method induced myelomeningocele defect in the offspring. Sham group animals were fed olive oil. Control dams didn?t take any medication. Fetuses were collected at embryologic day 22 (E22). Pregnant rats anesthetized by ether and euthanized by cervical dislocation. Fetuses were delivered by cesarean section. Myelomeningocele have been defined by observing the myelomeningocele sac at the back of the fetuses. Seven fetuses collected in myelomeningocele and sham groups each and 5 fetuses in control group. Fetal bladders were excised and fixed with 4% paraformaldehyde. Interstitial Cajal cells were evaluated by immunohistochemistry.Results: Interstitial Cajal cells were found in the entire group. These cells have the same morphological characteristics which had described earlier in gastrointestinal system and the bladder. The density of the ICC in the myelomeningocele group was found significantly less when compared with the other groups (p<0.05).Conclusion: The bladder dysfunction might be related to the lesser density of the ICC in the neurogenic bladder due to myelomeningocele.Key Words: Myelomeningocele, neurogenic bladder dysfunction, interstitial cells of Cajal, C-kit