The Estimation of Fibrinolytic Components by Means of the Lysis Time Method

Lassen, Mogens

doi:10.3109/00365515809051241

Cited by 33 publications

(13 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In vitro loss of UK to surfaces and its recovery by gelatin has been described previously (21,22) and is confirmed by the present observations. Plasmin and thrombin, however, do not influence UK adsorption to surfaces or the activity of UK itself.…”

Section: Living Cellssupporting

confidence: 80%

Increased Plasminogen Activator (Urokinase) in Tissue Culture After Fibrin Deposition

Bernik¹

1973

J. Clin. Invest.

106

View full text Add to dashboard Cite

A B S T R A C T Lysis of fibrin in tissue culture has been shown to be due to plasminogen activator identified immunologically as urokinase. The present study examines fibrinolytic events in culture, particularly mechanisms leading to increased urokinase levels and accelerated fibrinolysis.Deposition of fibrin on cells in culture was followed by a two-to six-fold increase in urokinase in the supernates and rapid disappearance of the fibrin. Investigation of factors that might be responsible for these events (including fibrin, fibrinogen, vasoactive stimuli, and the enzymes thrombin and plasmin) indicated that the enhanced urokinase yields were mediated through plasmin and thrombin.Study of the possible modes of action of thrombin and plasmin indicated that these enzymes are capable of acting on the cells themselves as well as on cell-produced material. The effect on cells was manifested by mitotic activity or, occasionally, cell injury and death. Although these effects influenced urokinase levels, enhanced yields were explained best by the action of enzymes on cellproduced material. Studies with plasmin and thrombin, and also trypsin, indicated that proteolytic enzymes may act in various ways-affect the stability of urokinase, interfere with inhibition of urokinase by naturally occurring inhibitor(s), and induce urokinase activity from inactive material. Plasma and thrombin appeared to act primarily through the latter mechanism.Inactive material, which gave rise to urokinase upon exposure to proteolytic enzymes and which may represent urokinase precursor, was found in cultures of kidney, lung, spleen, and thyroid. Urokinase in such inactive state appears to be readily accessible to activation by enzymes, particularly plasmin and thrombin, thus Abstract of preliminary results appeared in 1970 Clin. Res. 18: 398.

show abstract

Section: Living Cellssupporting

confidence: 80%

Increased Plasminogen Activator (Urokinase) in Tissue Culture After Fibrin Deposition

Bernik¹

1973

J. Clin. Invest.

106

View full text Add to dashboard Cite

show abstract

“…To obtain measurable lysis times, small concentrations of streptokinase had to be used, which activated only a fraction of the fibrinolytic factors in plasma. However, measurement of the total proactivator, after its complete saturation with streptokinase as suggested by Lassen (1958), also did not reveal a significant reduction of proactivator in (A+ B)-dep. The results suggest that proactivator and component A are not identical.…”

Section: Bovine Fibrinogen (Armour Laboratories);mentioning

confidence: 99%

“…Two perpendicular diameters (dl, d2) of each lysis area were measured and the area calculated as (dc +d2)2.7T/16. Plasminogen proactivator in plasma was measured by the following modification of Lassen's (1958) method. Human plasma was precipitated with cold acetone, and then redissolved and incubated with an excess of streptokinase (10-000 u./ml.).…”

Section: Bovine Fibrinogen (Armour Laboratories);mentioning

confidence: 99%

Kinin formation and fibrinolysis in human plasma

Eisen¹

1963

The Journal of Physiology

View full text Add to dashboard Cite

Previous experiments (Eisen, 1963) (1960) have reported quantitative differences in the distribution of plasmin and of kallikrein during the separation of plasma euglobulin, in the effects of acetone on their precursors in plasma, and in the response of these enzymes to trypsin inhibitors. Moreover, the vasodilating potency of acetone-treated plasma could not be accounted for by the plasmin activatable in such plasma. Bhoola, Calle & Schachter (1960) found that a commercial preparation of human plasmin plus streptokinase, and preparations of hog serum kallikrein, contained different ratios of fibrinolytic, plasma kinin-forming, and capillary permeability-increasing activities.

show abstract

“…At varying intervals, the original culture media were changed to serum-free medium, BME, containing 0.2% gelatin to prevent adsorption of activator to the glass surfaces (25). In some of the cultures 2% serum was added to this medium.…”

Section: Methodsmentioning

confidence: 99%