Release of arachidonic acid from vascular endothelial cells: Fatty acyl specificity is observed with receptor-mediated agonists and with the calcium ionophore A23187 but not with melittin
| Autor: | Janet E. Jones, Miriam D. Rosenthal |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
Physiology
Clinical Biochemistry Bradykinin Prostacyclin Arachidonic Acids Melittin chemistry.chemical_compound 8 11 14-Eicosatrienoic Acid Phospholipase A2 medicine Humans Calcimycin Cells Cultured chemistry.chemical_classification Arachidonic Acid biology Fatty Acids Thrombin Fatty acid Cell Biology Melitten Bee Venoms chemistry Biochemistry Fatty Acids Unsaturated biology.protein Arachidonic acid Endothelium Vascular Histamine Polyunsaturated fatty acid medicine.drug |
| Zdroj: | Journal of Cellular Physiology. 136:333-340 |
| ISSN: | 1097-4652 0021-9541 |
| Popis: | Vascular endothelial cells respond to a variety of physiological and pharmacological stimuli by releasing free arachidonic acid from membrane phospholipids, thus initiating synthesis of prostacyclin. Previous work in our laboratory has demonstrated that the thrombin-stimulated deacylation is specific for arachidonate and structurally similar polyunsaturated fatty acids that contain a delta-5 double bond. We now report that histamine, bradykinin, and the calcium ionophore A23187 exhibit the same fatty acid specificity as does thrombin. Experiments with both human umbilical vein and calf pulmonary artery endothelial cells indicate that these agonists stimulate the release of previously incorporated [14C]arachidonate but not 8,11,14-[14C]eicosatrienoate or [14C]docosatetraenoate. By contrast, melittin stimulates the release of 8,11,14-eicosatrienoate, docosatetraenoate, and oleate as well as arachidonate. These results suggest that histamine, bradykinin, and A23187 activate a common calcium-dependent phospholipase A2. Melittin appears either to alter the substrate specificity of the receptor-linked phospholipase A2 activity or to activate additional enzymes as well. |
| Databáze: | OpenAIRE |
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