Hyaluronidase and antidiuretic activity in urine of man

Abstract

Until recently the action of the antidiuretic hormone has been described as restoring 'water balance by promoting the reabsorption of the osmotically free water left by the distal reabsorption of Na. Under the action of the hormone this water is reabsorbed; in its absence this water is excreted' (Smith, 1956). Wirz (1956) has suggested an explanation of the mechanism of water reabsorption. He, and later Gottschalk & Mylle (1959), showed by micropuncture study in the rat that fluid in the first half of the distal tubule was hypotonic to plasma under all conditions of hydration, but that in dehydrated animals it became isotonic in the second half of the distal tubule and hypertonic in the collecting ducts. In the kidney producing a concentrated urine the tubular fluid comes into osmotic equilibrium first with the cortical tissue and later, in the collecting tubules, with the medullary tissue which is known to be increasingly hypertonic towards the papilla. According to Wirz's theory, the essential action of vasopressin is to increase the permeability to water of the distal parts of the nephron and collecting ducts. In 1958 Ginetzinsky found that the urine of several mammals contained hyaluronidase: this disappeared during water diuresis, but was present during osmotic diuresis, in the dog. In a histological study in rats Ginetzinsky observed that the cement substance between the cells of the collecting tubules reacted as hyaluronic acid when the animals were water-loaded, but as its polymerization products when they were dehydrated. He concluded that when stimulated by the antidiuretic hormone, the cells of the collecting tubules secrete hyaluronidase, which in turn depolymerizes the mucopolysaccharide complex of the basement membrane of the tubules, hence making 'the structures separating the tubule lumen from the interstitial tissue permeable to water. The hypotonic fluid in the tubules then follows the osmotic gradient and undergoes facultative reabsorption' (Ginetzinsky, 1958). This was a new approach to a process which had hitherto been difficult to envisage. It seemed, therefore, of interest to test Ginetzinsky's hypothesis by comparing the excretion of hyaluronidase and antidiuretic activity in urine under various conditions in man.

Renal excretion of hyaluronidase and calcium in man during the antidiuretic action of vasopressins and some analogues

“…of oxytocic activity) shows no activity, a result in agreement with those of other observers (Cross, Dicker, Kitchin, Lloyd & Pickford, 1960 Hyaluronida.e concentration. As found previously (Dicker & Eggleton, 1960), hyaluronidase could be detected in the urine at a relatively slow rate of flow, and its concentration was then more or less quantitatively related to rate of flow, as may be seen in Figs. 3 and 5.…”

“…Repeated measurements of the same solution indicated that the mean error of a single determination was about + 2 %, or + 5 % if the concentration was less than 250 m-osmole/l. Hyaluronidase was determined by change in viscosity of hyaluronic acid (Dicker & Eggleton, 1960). The molecular weight of the carbowax used in concentrating the urine samples (15,000-20,000) is close to the pore size of the Visking tubing in which it was contained, and with some batches slight leakage occurred through the tubing.…”

“…CoUege London (Recived 22 February 1961) Following the earlier observation of Ginetzinsky (1958) on dogs and rats, it was shown (Dicker & Eggleton, 1960) in man that hyaluronidase was present in urine secreted at a slow rate of flow; it disappeared during a water or alcohol diuresis and reappeared when the diuresis was suppressed by injection of vasopressin. Commercial preparations of vasopressin are extracted either from ox or from hog posterior pituitary glands, or from a mixture of both, and are standardized in terms of pressor units.…”

Metabolism and kidney function in the pouch young of the macropod marsupial Setonix brachyurus

“…The ability to form a hypertonic urine according to the 'counter current multiplier' theory may be affected by several factors, including the length of the loops of Henle, the plasma urea concentration and the ability of the kidney to respond to antidiuretic hormone . However, and Dicker & Eggleton (1960) consider that the latter factor is not important in this respect. Histological examination of the kidney of Setonix shows that growth during the first 100 days after birth consists mainly of the formation of new nephrons with a subsequent elongation of these tubules in the older animals.…”

Viscosity‐reducing activity of tissues in the rat

“…The buffer system was the citric-acid-phosphate buffer (Mcllwaine, 1921). When necessary, samples of supernatant fluids from tissues were concentrated by dialysis against carbowax 20 M (Dicker & Eggleton, 1960, 1961.…”