Vasoregulatory Substances Synthesized by the Endothelium
| Substance . | Principal Effect . | Other Effects . | Secretion . | Compound . | Precursor Compound . |
|---|---|---|---|---|---|
| NO (nitric oxide) | Vasodilatation | Maintains basal tone of vessels; inhibits leukocyte adhesion; inhibits platelet adhesion, activation, secretion, and aggregation; promotes platelet disaggregation; inhibits smooth muscle cell migration and proliferation | Paracrine/Constitutive and induced by thrombin, ADP, bradykinin, substance P, muscarinic agonists, shear stress, cyclic strain, cytokines | Heterodiatomic free radical | L-arginine |
| PGI2 (prostacyclin) | Vasodilatation | Retards platelet aggregation and deposition | Paracrine/Induced at sites of vascular perturbation | Eicosanoid | Arachidonic acid |
| PAF (plateletactivating factor) | Vasoconstriction | Promotes leukocyte adhesion at cell surface | Juxtacrine/Induced | Phospholipid | Arachidonic acid |
| ET-1 (endothelin-1) | Vasoconstriction | Mitogen for smooth muscle cells; modulates effect of numerous compounds | Paracrine/Induced by hypoxia, shear stress, and ischemia | 21 Amino acid peptide | Preproendothelin-1 (203 amino acids) |
| Substance . | Principal Effect . | Other Effects . | Secretion . | Compound . | Precursor Compound . |
|---|---|---|---|---|---|
| NO (nitric oxide) | Vasodilatation | Maintains basal tone of vessels; inhibits leukocyte adhesion; inhibits platelet adhesion, activation, secretion, and aggregation; promotes platelet disaggregation; inhibits smooth muscle cell migration and proliferation | Paracrine/Constitutive and induced by thrombin, ADP, bradykinin, substance P, muscarinic agonists, shear stress, cyclic strain, cytokines | Heterodiatomic free radical | L-arginine |
| PGI2 (prostacyclin) | Vasodilatation | Retards platelet aggregation and deposition | Paracrine/Induced at sites of vascular perturbation | Eicosanoid | Arachidonic acid |
| PAF (plateletactivating factor) | Vasoconstriction | Promotes leukocyte adhesion at cell surface | Juxtacrine/Induced | Phospholipid | Arachidonic acid |
| ET-1 (endothelin-1) | Vasoconstriction | Mitogen for smooth muscle cells; modulates effect of numerous compounds | Paracrine/Induced by hypoxia, shear stress, and ischemia | 21 Amino acid peptide | Preproendothelin-1 (203 amino acids) |
Principal regulatory compounds synthesized by the endothelium, their effects on the vasculature and other processes, their mode of secretion, and the nature of their chemical composition and precursor compound.