Urotensin-II Immunoreactivity in Children with Chronic Glomerulonephritis

Background. Human urotensin-II (hU-II) is one of the most potent vasoconstrictors in mammals. To our knowledge, there is no study about the role of U-II in childhood glomerulonephritis.We first determined the expression of h U‐II in kidneys of children with chronic glomerular diseases. Methods. Normal human kidneys were obtained from postmortem biopsies and compared with the kidney biopsy specimens of 24 children with membranoproliferative glomerulonephritis (MPGN) and 6 children with membranous GN. Kidney needle biopsies in 10% neutral buffered-formalin prior to routine processing through to embedded blocking sections were cut, and immunohistochemical reactions were performed on parafin-embedded tissue by an avidin-biotin peroxidase complex method. The antibodies used in the present study were hU-II. The positivities were revealed as weak (+), moderate (++), and severe (+++), according to the color intensity. Results. In kidneys of children with MPGN, differently fom the normal kidneys, more dense U-II immunoreactivity was seen in the glomerular basement membrane (GBM), glomerular mesangium, Bowman capsule, and tubules. Interestingly, we also observed U-II immunoreactivity in crescents. In children with MGN, U-II was mostly seen in GBM and Bowman capsule. Conclusion. Our findings suggest that U-II may have a possible autocrine/paracrine function in the kidneys, and may be an important target molecule in studying renal pathophsiology.