蛍光抗体法によるNephrotoxin腎炎の研究 : VI.とくに髄質内層トリプシン消化超遠心上清に対する抗血清の腎炎惹起能力について

抄録

There are several reports that renal medulla contains nephrotoxic antigen, which were mainly confirmed by in vitro studies, such as absorption or precipitation procedures. However, the localization of nephrotoxic antigen in medulla is still obscure and the different results were reported on the production of nephrotoxic serum nephritis (NTN) using antiserum against renal medulla. In this paper, tryptic digested ultrasupernatant of rat inner medulla (TR-M) were used as an antigen for the production of NTN, because the active principle of nephrotoxic antigen in glomerular basement membrane (GBM) is proved to be present in the tryptic digested ultrasupernatant of renal cortex. TR-M, as the antigen, could produce more potent nephrotoxic antiserum than simple emulsion of medulla, if the medulla contained nephrotoxic antigen. The antiserum against TR-M was obtained immunizing rabbits by the alum precipitation method. The injection of anti TR-M could produce typical NTN both clinically and histologically; Proteinuria from 50 to 100 mg/day appeared next day after the injection and continued during the observation period of I to 60 days. Histologic examination showed severe glomerulitis in all rats tested, but tubules in cortex and medulla showed no primary changes attributable to the injetion of antiserum except marked endothelial cell proliferation of vasa recta in outer medulla in several rats. The injection of FITC labeled anti TR-M revealed that all the antisera injected fixed only in GBM. The immunofluorescent staining of normal rat kidney with FITC labeled anti TR-M showed the following specific localization of anti TR-M. I) Cortex; GBM, Bowman's capsule, tubular BM and media of small blood vessels. II) Outer medulla; tubular BM and capillary BM of vasa recta. III) Inner medulla; tubular BM and capillary BM. Tubular BM and capillary BM was easily differentiated in outer medulla, but was very diffiuclt in inner medulla. From these studies it is apparent that antisera against TR-M have an ability to produce NTN, and the nephrotoxic antigen in medulla exists in tubular and/or capillary BM. The nephrotoxic antigenicity of capillary BM is already well known, however, the relationship between tubular BM and nephrotoxic antigenicity needs further elucidation.