Antiplasmin activity of electrophoretically separated human serum fractions

Abstract

SYNOPSISThe antiplasmin which migrates electrophoretically with the alpha2 globulins preponderates in effect over that of the alpha1 migrating antiplasmin. This preponderance persists at physiological pH value in vitro and the significance of this finding is discussed.No evidence has been obtained of the existence of anti-urokinase activity in antiplasmin-free serum fractions.The fibrinolytic activity of the enzyme plasmin is inhibited by two different plasma components which migrate electrophoretically with the alpha, and alpha2 globulins respectively. The alpha, migrating antiplasmin combines relatively slowly and irreversibly with plasmin in a manner which is temperature dependent. The alpha2 migrating antiplasmin produces an immediate, temperature-independent inhibition which is more readily reversible (Norman, 1958(Norman, , 1960. In addition, it has been suggested that antiplasmin activity resides largely in the alpha2 globulin fraction (Jacobbson, 1955).Plasmin neutralization may, therefore, be predominantly due to an antiplasmin fraction which combines in a rapid and reversible manner with plasmin. As this concept is of importance, we have undertaken studies of the antiplasmin and antiurokinase activity of each fraction of normal human serum separated by curtain electrophoresis. In this paper, we report the antiplasmin activity of each such fraction, at the pH of the electrophoretic separation and at the physiological pH value, and the anti-urokinase activity of the fractions at the pH of separation, over a range of urokinase concentrations.It has been found that, in this experimental system, the potency of the alpha2 antiplasmin preponderates over that of the alpha1 antiplasmin at both pH values examined. We consider, therefore, that plasmin neutralization is likely to be predominantly rapid and reversible in the circumstances in which these characteristics are typical of the alpha2 antiplasmin.Received for publication 14 October 1965. MATERIALSThe following were used:-Fibrinogen, human, grade L (bottles of 1 g.), Kabi Pharmaceuticals Ltd., plasminogen, human, grade B (120 casein units/vial), Kabi Pharmaceuticals Ltd; plasmin, human, grade B (28 casein units/ vial), Kabi Pharmaceuticals Ltd.; urokinase reference standard, human (2,400 Ploug units/vial), Leo Laboratories Ltd.; thrombin reagent, bovine (2,500 units/vial), Leo Laboratories Ltd.; veronal buffer pH 7 4, 0-154 M.: sodium diethyl barbiturate 11-745 g., sodium chloride 14-67 g., hydrochloric acid 0-1 N 430 ml., distilled water to 2 litres; and Tris citrate buffer pH 8-6: 0-076 M. Tris 9-21 g./litre, 0 005 M. citric acid 1-05 g./litre. METHODFresh human serum was obtained on three separate occasions from a male subject without evidence of arterial disease or altered fibrinolytic activity and each specimen was individually separated by curtain electrophoresis into 47 fractions using Tris citrate buffer pH 8-6. On each occasion, serum was applied at a rate of 38 ml./day. A potential of 2,100 volts was used for a period of 48 hours on two occasions...

Intraglomerular fibrin, platelet aggregation, and subendothelial deposits in lipoid nephrosis

“…Under high magnification this material appeared very finely granular and did not resemble fibrin. It occasionally contained what appeared to be remnants of sub- [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. This was observed apparently unassociated with platelet aggregation in nine cases.…”

Effect of age, sex, and diurnal variation on the human fibrinolytic system

“…The biological significance of this sex difference in anti-urokinase activity may be appreciated from the Trasylol reference curve for the experimental system used (Mann, 1966 …”

“…PLASMA ANTI-UROKINASE ACTIVITY This was estimated twice on coded aliquots of each specimen by an adaptation of the method of Mann (1966). Individual tests were carried out by adding to 1 ml.…”

“…Plasminogen activation in blood is due to a heatlabile activator which can be demonstrated in subjects under physiological circumstances (Fearnley, Revill, and Tweed, 1952; Flute, 1960a and b;Sawyer, Fletcher, Alkjaersig, and Sherry, 1960). Free plasmin cannot be detected in the circulating blood, even in the presence of free activator (Sherry, Lindemeyer, Fletcher, and Alkjaersig, 1959;Sawyer, Alkjaersig, Fletcher, and Sherry, 1960), for such plasmin is rapidly neutralized by circulating antiplasmins, of which two types have been described (Norman, 1958; Norman and Hill, 1958).The human antiplasmin which migrates electrophoretically with the alpha-2 globulins combines rapidly and reversibly with plasmin (Norman, 1960) and predominates in inhibitory effect over the alpha-1 migrating antiplasmin (Mann, Cotton, and Jackson, 1966). Plasmin-antiplasmin neutralization may be, therefore, predominantly rapid and reversible, so forming a neutralized complex existing as a reservoir of fibrinolytic enzyme which can dissociate in the presence of fibrin (Ambrus and Markus, 1960).…”

“…The human antiplasmin which migrates electrophoretically with the alpha-2 globulins combines rapidly and reversibly with plasmin (Norman, 1960) and predominates in inhibitory effect over the alpha-1 migrating antiplasmin (Mann, Cotton, and Jackson, 1966). Plasmin-antiplasmin neutralization may be, therefore, predominantly rapid and reversible, so forming a neutralized complex existing as a reservoir of fibrinolytic enzyme which can dissociate in the presence of fibrin (Ambrus and Markus, 1960).…”