URINARY KALLIKREIN DETERMINATION AND ITS PHYSIOLOGICAL ROLE IN HUMAN KIDNEY

Abstract

On the purpose to investigate the physiological role of kallikrein in the human kidney, its activity in human urine (Human urinary kalikrein; H. U. K.) was determined by TAME (p-toluene sulfonyl-1-Arginine methyl ester) assay described by Moriya.
The values obtained with this method well correlated to those obtained as kinin releasing activity where released kinins were assayed by observing the contraction of isolated guinea pig ileum.
To obtain normal range, 6 healthy males and females were examined. The results were as follows: male, average 63 E. U. per day (ranged 0-126); female, average 39 E. U. per day (ranged 0-68).
H. U. K. activity in patients with primary aldosteronism showed significant high values. In patients with Cushing's syndrome, renal lesions and others were within normal range. H. U. K. in primary aldosteronism decreased after extirpation of the adrenal adenoma.
H. U. K. activities in 7 cases of renal homotransplantation were determined serially. Soon after the transplantation, most cases of them showed extremely low levels but in some cases showed relatively high levels.
In the cases which showed relatively high levels, the activity also decreased gradually and became almost zero before their endstadium. In 3 cases out of 6 who finally succumbed, as Werle reported, H. U. K. decreased before blood urea nitrogen level increased.
The role of kallikrein in primary aldosteronism was discussed from the standpoint of sodium and water balance and it is suggested that kallikrein in human kidney may be one of the factors controlling homeostasis of human body.
The decrease of H. U. K. in the patients of renal transplantation is thought to be ascribable to tubular dysfunction or destruction caused by the rejection reaction.
The reason why H. U. K. diminishes before blood urea nitrogen levels rise may be that tubular cells are more easily damaged than glomerular cells under ischemic conditions.