IN-VITRO LIGATION OF URETERS AND URETHRA MODULATES FETAL MOUSE BLADDER EXPLANTS DEVELOPMENT

The compliance of the bladder which accommodates the holding and voidi ng of urine is influenced by the amount and type of collagen deposited as well as the packing and organization of collagen fiber bundles. Du ring fetal development, the accumulation of urine within the bladder l umen is associated with the maturation of the bladder's wall. Fetal mo use bladders can undergo maturation as organ cultured explants in defi ned medium. Polarized light optics of Sirius red-stained sections of f etal mouse bladders in organ culture for 4 days showed that the ligati on of both ureters and urethra promoted more orderly packing of collag en fiber bundles within the luminal edge of the lamina propria compare d to unligated bladder explants, It is proposed that ligation causes d ifferences in the development and organization of the collagen fiber b undles within the bladder wall. These differences are due to either in creases in intravesical pressure, the accumulation of growth factors w ithin the lumen or a combination of both.