934 P2X 3 RECEPTOR-EXPRESSION IN FETAL AND INFANT BLADDERS - THE BASIS FOR A NEW THERAPEUTIC CONCEPT FOR OVERACTIVE BLADDERS IN CHILDREN

Abstract

Introduction. The urothelium plays an active role in the regulation of urinary bladder function due to its sensorial properties. P2X3 receptors are critical components of this sensory pathway. They convey afferent information creating central nervous pain perception. We report the expressional time course of P2X3-receptors from fetal life to adulthood to rule out their possible implications in various bladder pathologies. Material and methods. Fetal, neonatal, and adult bladder specimens were obtained and immunostained with anti-P2X3 antibodies. A computer assisted microscope evaluated the intensity, extension, and tissue distribution. results. P2X3-receptors are widely abundant in the suburothelial space containing the nerve plexuses. These suburothelial nerve fibers expressing P2X3 were demonstrated in fetal as well as infant bladder tissue. However, the overall P2X3 expression was less intense in fetuses when compared to infants. In contrast to previously described adult specimens, we found a higher density of P2X3 receptors in infants and fetuses. Conclusions. This is the first study investigating the expressional time course of P2X3 receptors during human fetal development as well as in infancy. The disproportionately strong expression of P2X3-receptors in infants may explain the process of reflective bladder emptying in non-toilet trained children. However, P2X3 is less abundant in adults with a normal voiding pattern. Correspondingly, overexpression or deregulation of the P2X3 receptor complex may explain the lack of significant pathological findings in children with overactive bladder. Nonetheless, the inconsistent expression of P2X3 receptors in fetuses and infants may permit new therapeutic concepts.