Effect of ethyloestrenol on fibrinolysis in the vessel wall

The Effect of Phenformin and Ethyloestrenol on Fibrinolytic Activity in the Vessel Wall

In a study of 117 patients with recurrent venous thrombosis 65 patients were identified as having deficient fibrinolytic activity in the walls of veins obtained at biosy.

Administration of phenformin and ethyloestrenol enhanced natural fibrinolysis.

Δ4-Ethyloestrenol in Recurrent Deep Venous Thrombosis

Twenty-one patients with recurrent deep venous thrombosis were treated with an anabolic steroid (Δ4-ethyloestrenol) for up to 56 months. All had been shown to have a deficient fibrinolytic response to vascular occlusion and/or low vessel wall plasminogen activator content.

Therapy resulted in improvement in clinical and fibrinolytic parameters and no significant side effects were seen.

delta 4-ethylestrenol in recurrent deep venous thrombosis

In a study of 21 patients with recurrent venous thrombosis and/or thrombophlebitis, fibrinolytic activity measured after venous occlusion was significantly improved after treatment with 6 mg delta 4-ethylestrenol (Orgabolin) daily. Seven of the 21 patients had abnormally low vessel wall plasminogen activator content, which normalised during treatment. No tendency to develop resistance to the drug was observed during treatment for periods up to 56 months. This improvement was shown to be combined with a significant lower (p less than 0.001) incidence of thrombosis.

Effects of progestogens on haemostasis

Epidemiological data suggested an involvement of the progestogen component in the pathomechanism of venous and arterial diseases during intake of oral contraceptives. The influence of progestogens on haemostasis parameters depend on type and dose of the progestogen, the presence of an estrogen, the route of application, and the duration of use. Treatment of women with progestogen-only preparations caused only minor effects on coagulation and fibrinolysis. Similarly, during hormone replacement therapy with natural estrogens, the additional application of progestogens induced no unfavourable changes on haemostasis. In contrast, the use of ovulation inhibitors resulted in an acceleration of coagulation and fibrinolysis. This is primarily induced by the marked action of ethinylestradiol on hepatic and vascular function. Progestogens with androgenic properties may counteract the estrogen-induced changes in the hepatic synthesis of platelet aggregation and readiness for coagulation. Estrogen and progesterone receptors are localized in endothelial and smooth muscle cells of the vessel wall, but there are differences in the response of veins and arteries to sex steroids. Estrogens and progestogens may influence collagen and elastin synthesis, and the release of vasoactive compounds and of factors controlling fibrinolysis from endothelium. In veins, progestogens may increase distensibility and capacitance resulting in a decreased blood flow. In predisposed women, this may lead to venous stasis and thrombosis. In arteries, progestogens may act as vasoconstrictors, and may enhance vasospasms at sites of injured endothelium which finally may lead to ischemic diseases.

Ethinylestradiol and d-norgestrel regulation of plasminogen activator in a human melanoma cell line

The influence of ethinylestradiol (EE2) and d-norgestrel (d-Ng) was studied in a melanoma cell line producing a tissue-type plasminogen activator (t-PA) very similar to or identical with the t-PA isolated in extracts from human uterus. The cell cultures were exposed to the two contraceptive steroids by addition of EE2 or d-Ng dissolved in a week alcoholic solution to the culture media, in which the released t-PA was assayed by an immunoradiometric method. A strongly stimulating effect of ethanol (0.76% w/v) on the t-PA production was demonstrated. Whereas, EE2 in the concentration of 1.7 X 10(-7)M and d-Ng in the concentration of 8.6 X 10(-7)M both caused a significantly reduced secretion of t-PA, and this effect was independent of whether the cell cultures were grown to confluency in the presence of the two synthetic steroids or not. It was concluded, that the two contraceptive steroids had an inhibitory effect on the production of t-PA in melanoma cell culture.

Fibrinolytic activity in plasma and vessels of the hind leg in rats treated with ethinylestradiol and D-norgestrel

The separate effect of ethinylestradiol (4 micrograms/kg b.w./day) and d-norgestrel (20 micrograms/kg b.w./day) on the fibrinolytic activity in plasma and in vessel walls of the hind leg was investigated in an experimental study on rats. No hormonal effect on the fibrinolytic activity in plasma was registered. However, a significantly increased fibrinolytic activity in the vessel wall of the distal hind leg was demonstrated in the d-norgestrel-treated rats with plasma levels well below those reported in women using combined contraceptive pills. On the contrary, the fibrinolytic activity of the vessel wall was uninfluenced in the ethinylestradiol-treated rats with plasma levels corresponding to those in women on contraceptive pills containing 30 micrograms ethinylestradiol.

Prophylactic antithrombotic therapy with stanozolol in patients with familial antithrombin III deficiency

Three patients with familial antithrombin III deficiency underwent a trial of prophylactic antithrombotic therapy with stanozolol. An increase in plasma fibrinolytic activity and antithrombin III was seen. Acute venous thrombosis occurred in two patients; in the first patient thrombosis was precipitated by venography but in the second no precipitating factor was found. Our experience suggests that stanozolol is not a suitable prophylactic agent in patients with familial antithrombin III deficiency.

The fibrinolytic system in man

The existence of a system in the human body capable of inducing the dissolution of endogenous pathologically formed thrombi was appreciated in ancient times. Considered in detail in this article are the data that have elucidated the physiologic regulation of which plasmin formation is dependent on, the plasma concentration of plasminogen, availability of activators of plasminogen in the plasma and surrounding tissue environment, the concentration of naturally present inhibitors, and the existence of fibrin in the circulation. Important in this rapidly progressive scientific discipline is consideration of the factors which control the synthesis of the components of this proteolytic enzyme system. Recently abundant information has indicated that this plasminogen-plasmin proteolytic enzyme system can be utilized therapeutically. Knowledge of the mechanisms of this system has permitted identification of agents that can be exogenously administered to releave thrombotic obstruction to blood flow in the venous (pulmonary emboli, deep vein thrombosis) and arterial (peripheral and central vessels) circulatory systems. Particularly important is the demonstration that thrombolytic agents can directly attack and alleviate the immediate cause of acute myocardial infarction. As a result of the innovations in the present decade, it is evident that the plasminogen system can be advantageously employed to reverse the pathologic effects of all thrombotic diseases.

Abnormal fibrinolysis in retinal vein occlusion

Some cases of central and branch retinal vein occlusion are associated with and may be caused by abnormal fibrinolytic mechanisms. The abnormality we described is that of plasminogen activator enzyme deficiency, which is a treatable condition. That seven cases were seen by one practitioner in a two year period may indicate that this particular condition is under-recognised.

Deep venous thrombosis of the arm: a study of coagulation and fibrinolysis

Sixty consecutive patients with phlebographically verified deep venous thrombosis of the upper arm were studied for disorders of coagulation and fibrinolysis. No appreciable increase in abnormalities of the factor VIII complex, antithrombin III, or inhibitors of activators of fibrinolysis were found. A decreased fibrinolytic defence mechanism, evident either as a deficient release capacity of fibrinolytic activators from the vein during stasis or as decreased fibrinolytic activity in the vein wall as determined histochemically, was found in 26 out of 53 patients studied (49%). It is concluded that deep venous thrombosis of the upper arm is a multifactorial disease. An impaired fibrinolytic defence mechanism is one of the factors that may be of pathogenetic importance.

The effect of the anabolic steroid stanozolol on tissue plasminogen activator activity and plasmin inhibition in the rat

The anabolic steroid stanozolol administered orally in male Sprague-Dawley rats induced a dose- and time-dependent increase in tissue plasminogen activator activity. The increase was highest in lung, lowest in heart, and intermediate in aorta and kidney. A slight increase in plasmin inhibition was noted only in the heart.