Viscosity‐reducing activity of tissues in the rat

The isolation of hyaluronic acid and chondroitin sulphate from kidneys and their reaction with urinary hyaluronidase

“…As the molecular weight of hyaluronidase appears not to exceed 14,000 (Malmgren, 1953) the possibility that it may be ifitered through the glomeruli cannot be dismissed. In that respect it should be noted that according to Cobbin & Dicker (1962) and to Dicker & Elliott (1963) hyaluronidase activity with an optimum pH similar to that found in the urine could be found also in plasma, kidney, spleen and liver. Though teleological arguments should be treated with care, it is of interest to mention that estimation of pH values of urine throughout the entire length of the nephron have shown that values of the order of 4-0-4-2 have been observed in the collecting tubules, in the non-diuretic rat (Gottschalk, Lassiter & Mylle, 1960;Pitts, 1963).…”

“…In spite of this, authors have used commercial hyaluronidase extracted from testes or from bacteria and claimed results which fitted their theory more than the facts. In the investigations by Cobbin & Dicker (1962), Dicker & Elliott (1963) and Dicker & Eggleton (1960 no attempt at purification of the enzyme was made. It was thought of interest therefore to see whether some degree of purification could be achieved and whether the results of Cobbin & Dicker (1962) could be confirmed when a different method of measuring the enzymic activity was used.…”

“…According to Ginetzinsky, Vasilyeva & Natochin (1961) the site of secretion of the enzyme is in the distal part of the nephron. Urine hyaluronidase appears to be a different enzyme from that prepared commercially from testes or semen of mammals (Cobbin & Dicker, 1962;Bollet & Bonner, 1963;Dicker & Elliott, 1963). Though the presence of hyaluronidase activity in the urine appears to be associated with the concentration of the latter, the actual role of the enzyme is still not clear.…”

“…It seemed therefore of some importance to see whether hyaluronic acid could be extracted from kidneys and if so, whether it is located in the medulla and/or the cortex. At the same time, it was thought of interest to re-investigate the nature of the urinary hyaluronidase by a method different from that used previously (Dicker & Eggleton, 1960;Cobbin & Dicker, 1962;Dicker & Elliott, 1963).…”