Permeabilizing Effects of Heparin and Heparin-like Substances

Abstract

AT a concentration of 0.001 per cent (w/v), heparin provokes liberation of the clearing factor from isolated perfused rabbit heart¹. Desulphurated α-heparin and β-heparin have a similar activity, but chondroitinsulphuric acid and hyaluronic acids do not, in spite of their great chemical similarity to the three active substances². Furthermore^3–5, heparin at 0.4 gm. per cent (w/v) induces an obvious diastolizing effect on a Straub preparation of isolated frog heart. Such cardiac diastolization can also be obtained by desulphurated heparin and by β-heparin at the same concentration, but not by chondroitinsulphuric acid or hyaluronic acid; only the action of β-heparin is irreversible. Diastolization is completely abolished if an over-dosage of 12 mgm. per cent of calcium ions is added to the Ringer solution.