726 BMP-7 SERVES AS A PROGNOSTIC BIOMARKER IN EVALUATING URETEROPELVIC JUNCTION (UPJ) OBSTRUCTIONS

(2&20 ng/ml) and/or with soluble TGFR, which blocks bioactivity. Organs were harvested after 6 days and the expression of Smooth Muscle Actin( SMA)& PCNA(proliferation) were assessed using immunohistochemistry. The muscle content of the UVJ and ureter were analyzed by flowcytometry. RESULTS: TGF& TGFR2 positive cells were immunodetected in embryonic ureters. The TGFexpression was highest on E18 and had decreased postnataly. Exogenous TGFdecreased ureterovesical(UV) muscle differentiation and proliferation. The longitudinal muscle fibers were significantly less in TGFexplants. TGFalso decreased the proportions of cells expressing SMA. SolubleTGFR blocked the effects of exogenous TGF. CONCLUSIONS: In organ-culture, exogenous TGFpostpones the UV smooth muscle proliferation and affects the muscular structure. Whether the effects of TGFare direct or indirect these form an invitro-megaureter model. The finding that TGFis highest in embryonic ureters in-vivo and decreases postnataly,suggests that a pathological persistance might potentialy explain the pathogenesis of primary megaureters.