STUDIES ON THE CHANGES OF GLOMERULAR PERMEABILITY IN PROTEINURIA

Abstract

For the purpose to study the passway of high molecular substances through glomerular capillary membrane and the permeability of that membrane in renal diseases, we used the isolated rabbit's kidney perfusion technique at 4°C (=cooled kidney) and Dextran preparation in the clearance method in order to inhibit the tubular reabsorption.
(1) The incorporation of Imferon (Iron Dextran complex) into glomerular capillary cells in the rabbit, conditioned by normal, Masugi's nephritis, and mercurials damaged, was identical between the cooled kidney case and the control by electronmicrosocpy. Transport of high molecular substance, protein or Dextran, passed through cells in glomerular capillary membrane, is considered to be made not only actively but passively.
(2) Urinary protein contents derived from isolated rabbit's kidney perfused with ice cold serum was supposed to resemble to that of glomerular filtrate. The protein concentration of glomerular filtrate was increased with the elevation of pressure and protein concentration on perfusion. The glomerular filtrate protein concentration was 25.9mg/dl in normal cases' average. After this procedure, kidney without injuring of glomerular capillary membrane was assured electronmicroscopically. Their fraction had much albumin, less globulin than that of serum. In pathologic states conditioned by mercurial injury and Masugi's nephritis, the glomerular filtrate contained increased protein concentration with increased globulin, and these results suggested increased permeability.
(3) The type of distribution curve which represented glomerular permeability in various renal diseases was devided to three main type. This curve indicated permeability more appropriately than mean effective radius. In addition to this results, there should be injury of glomerular capillary membrane, Dextran fraction, over 100, 000 molecular weight, was excreted in urine.