Ruolo del transforming growth factor-beta (TGF-beta) nella patogenesi del megauretere primitivo. Studio istologico ed immunocitochimico.

Histologic and Transforming Growth Factor Beta (TGF-beta) immunostain patterns were sought in resected distal urinary tracts from 17 Primary Megaureter (PM) affected children, referred to surgery. Comparative observations were also carried out on embryonal and fetal ureteral buds of both humans and bovines. A reciprocal resemblance was mainly objectivized between the resected "narrowed" ureters of patients under 18 months, and the fetal ureteral buds at 26th and 38th gestational week. A development delay was irrespectively observed in PM "narrowed" ureters, at the longitudinal muscle-bundles in the parietal juxta-luminal compartment. A consistent TGF-beta immunostain cytoplasmic reaction there selectively depicted the growing mesenchymal lines, including both the undifferentiated single cells and the muscle-like profiled ones. These results agree with very recent reports perspecting a segmental maturation delay as a pathogenetic moment of PM. Because of the acquired potent TGF-beta inhibitory role on myoblasts differentiation, the present study substantiates a persistent TGF-beta role in perinatal ureter dilations.