Effects of some membrane-active and other compounds on thrombin-induced platelet aggregation

Zusammenfassung Substanzen, welche die thrombin-induzierte Plättchenaggregation hemmen, lassen sich in drei Hauptgruppen aufteilen: 1. membranstabilisierende Steroide, 2. Substanzen, welche die elektrischen Eigenschaften der Membran oder die Permeabilität oder beide beeinflussen, und 3. Substanzen, die eine Erhöhung des intrazellulären cAMP-Spiegels bewirken sollen. Eine Hypothese über die Hemmung der Plättchenaggregation durch Thrombin wird vorgeschlagen.

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Supported in part by Grants No. HE-01648 and No. HE-06350 from the National Heart and Lung Institute. Dr.Mason is a Markle Scholar in Academic Medicine and an N.I.H. Career Development Awardee.     

The effect of piroxicam on platelet aggregation

Summary Piroxicam inhibited aggregation of human and dog platelets caused by collagen, but not by adenosine diphosphate (ADP). Release of platelet ADP was inhibited by piroxicam.     

The effect of piroxicam on platelet aggregation.

Piroxicam inhibited aggregation of human and dog platelets caused by collagen, but not by adenosine diphosphate (ADP). Release of platelet ADP was inhibited by piroxicam.     

Alpha-tocopherol: Its inhibition on human platelet aggregation

Summary Alpha-tocopherol inhibits human platelet aggregation induced by arachidonate sodium, collagen, epinephrine, adenosine diphosphate or thrombin — arachidonate sodium being the most susceptible. The second phase of the biphasic platelet aggregation induced by epinephrine or adenosine diphosphate is preferentially inhibited.This work was supported by the Medical Research Council of Canada, Quebec Medical Council, and a Fraser Scholarship, McGill University. I thank Drs.K. N. Drummond andS. O'Regan for their comments.     

Effect of sympathectomy on platelet aggregation and blood coagulation in rats

Summary It is shown that the ability of blood platelets to aggregate in partially and completely sympathectomized rats is significantly lower than in intact animals. The blood clotting system of sympathectomized rats is hyperactive. The sympathectomy-provoked changes may be due to the increased content of adrenaline in the blood.     

Alpha-tocopherol: its inhibition on human platelet aggregation.

Alpha-tocopherol inhibits human platelet aggregation induced by arachidonate sodium, collagen, epinephrine, adenosine diphosphate or thrombin - arachidonate sodium being the most susceptible. The second phase of the biphasic platelet aggregation induced by epinephrine or adenosine diphosphate is preferentially inhibited.     

Beta-blocking drugs and human platelet aggregation in vitro

Riassunto L'effeto inibente di farmaci -bloccanti sull'aggregazione di piastrine umane indotta in vitro mediante ADP è risultato proporzionale alle dosi dei farmaci impiegati. La seguente scala gerarchica di potenza è disposta in ordine decrescente di attività: pindolol, K 4423, propranolol, INPEA.     

The effect of various beta-receptor blocking agents on platelet aggregation

Zusammenfassung Vier betarezeptorenblockierende Substanzen wurden auf ihre Fähigkeit untersucht, die Adenosindiphosphat-induzierte Thrombozytenaggregation in vitro zu hemmen. Dabei erwies sich die Dosis-Wirkungs-Relation bei LB-46 (Sandoz) am günstigsten, indem diese Substanz eine etwa fünfmal stärkere Aktivität als Propranolol aufweist. Ba-39 089 ist gegenüber Propranolol etwa zweimal weniger wirksam. Für I.C.I. 50 172 konnte bei gleicher Dosierung wie Propranolol überhaupt keine Hemmung festgestellt werden.     

The in vitro effects of several progestogens,estrogens and non-steroidal compounds with estrogenic activity on adenosine diphosphate induced guinea-pig platelet aggregation

Résumé Des disperisions aqueuses de progestogènes et estrogènes stimulent l'agrégation des plaquettes de cobaye produites par ADP in vitro. Le diéthylstilbestérol et l'hexestrol qui ne sont pas des stéroïdes, mais possèdent une activité estrogénique, ont un effet inhibitoire sur l'agrégation.