Production of prostacyclin by vascular endothelial cells
Autor: | W.G. van Aken, Ch Willems |
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Rok vydání: | 1979 |
Předmět: |
Blood Platelets
medicine.medical_specialty Umbilical Veins business.industry Prostacyclin Hematology medicine.disease Epoprostenol Vascular endothelium Endocrinology Platelet Adhesiveness Prostaglandin-Endoperoxide Synthases Physiology (medical) Internal medicine cardiovascular system medicine Prostaglandins Humans Platelet Endothelium Thrombus business Cells Cultured medicine.drug |
Zdroj: | Haemostasis. 8(3-5) |
ISSN: | 0301-0147 |
Popis: | One of the earliest events in thrombus formation is the adherence of blood platelets to the exposed subendothelium. Under normal conditions no platelet adherence to the vascular endothelium occurs. To study a possible interaction between endothelial cells and blood platelets, endothelial cells were isolated from the umbilical cord vein. These isolated cells could be identified as endothelial cells by the presence of the so-called Weibel Palade bodies and the FVIII:AG. After incubation of monolayers of endothelial cells with blood platelets an unstable substance which inhibits platelet aggregation is released from the endothelial cell. This substance could be identified as prostacyclin according to the following criteria: (1) Its formation could be blocked by pretreatment of the endothelial monolayers with indomethacin or tranylcypromin. (2) After preincubation of endothelial cells with [14C]-endoperoxide, chemically detectable amounts of [14C]-6-keto PGF1α, the stable end product of prostacyclin could be detected. (3) In incubation supernatants the presence of 6-keto PGF1α could be shown by means of gas chromatography. Monolayers of endothelial cells only synthesize prostacyclin when the cells are stimulated for example by mechanical stress or after addition of substances like arachidonic acid or thrombin. It has been suggested that apart from the aforementioned endogenous production of prostacyclin the endothelial cell may also synthesize prostacyclin using endoperoxides provided by platelets. In these studies the production of prostacyclin was measured as the inhibition of platelet aggregation. Comparison of the amount produced in the presence of buffer alone, with the amount formed in the presence of platelets, led to the suggestion that endoperoxides liberated by platelets were used by endothelial cells to synthesize prostacyclin. If, however, the retainment of the biological activity in these two systems is compared, then it appears that in the presence of plasma or platelets, prostacyclin is stabilized to a |
Databáze: | OpenAIRE |
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