STUDIES ON THE FIBRINOLYTIC ACTIVITY OF THE HUMAN KIDNEY

Abstract

The localization of the fibrinolytic activity in the kidney tissue and the origin of the urokinase are not fully understood.
The purpose of the present report is to study the localization of the tissue fibrinolytic activity and the changes of the fibrinolytic activity in various diseases of human kidney.
Examinations were made of kidneys in 53 autopsy cases and 49 operation cases with the 2M KSCN extraction method (Astrup's method) using human fibrinogen and with fibrinolytis autographs (Todd's method) using human fibrinogen.
The results were as follows.
1. A larger amount of tissue activator was extracted from the medulla than from the cortex of the kidney.
2. Lower activity was found in children and young adults than in adults.
3. No difference of the fibrinolytic activity was found between the saline perfused kidneys and the nonperfused kidneys by the 2M KSCN extraction method.
4. The fibrinolytic activity in the kidney was found in the wall of the intrarenal vessels by Todd' method. The activity seemed to be localized in the endothelium. The intensity of the activator activity of the vessels was roughly in the following order, 1) vasa recta and arcuate veins, 2) interlobular veins, venulae adjacent to glomerulus and subcapsular venulae, 3) glomerular capillaries. In addition to these vessels, fibrinolytic activity was found in the wall of arterioles, interlobular arteries, and arcuate arteries. In the glomerulus, fibrinolytic activity was found to be high in the vascular pole.
Fibrinolytic activity was not found in tubular epithelium, juxtaglomerular cells or epithelium of macula densa.
5. In cortical peritubular capillaries, fibrinolytic activity was not found, except for those around tubules adjacent to juxtamedullary glomeruli.
6. Very little fibrinolytic activity was found in a case of ischemic renal infarction which had completely lost the renal functions.
7. The relation between the degree of renal function disturbance and the degree of fibrinolytic activity was not always parallel.
8. In 9 cases of renal carcinoma (so-called Grawitz's tumor), fibrinolytic activity was not found in cancer cells, but in stromal capillaries.
9. Antifibrinolytic activity of the kidney tissue seemed to be higher in the cortex than in the medulla, and was considered to be the antiactivator activity.