Thrombin, 80 vasopressin

The release of NO from the endothelium is induced by various chemical substances, including acetylcholine polypeptides such as substance P, bradykinin, and arginine vasopressin histamine ATP/ADP a2-adrenoceptor agonists thrombin and Ca2+ iono-phores. NO formed in response to mechanical stimuli like shear stress or transmural pressure plays an important role in maintaining basal blood flow. Endothelial NO causes vasodilatation, decreased... 

In some cases, receptor inactivation, e.g., of the V2 vasopressin receptor, is mediated by agonist-induced enzymatic cleavage of the GPCR. This nonendocytic proteolysis is promoted by a plasma membrane-associated metalloprotease. Proteinase-activated receptors (PARs) such as the thrombin receptor also follow a distinctly different pathway. PARs require the enzymatic cleavage of their N terminus, and the newly generated N terminus activates the receptor. Once... 

In addition to PTX-sensitive Gps, cells appear to have PTX insensitive Gps, notably a PTX-insensitive Gp)c. Functional G proteins of this type have been defined in several cells in pituitary cells, responsive to TRH [106,107] in liver, responsive to vasopressin, angiotensin II and aradrenergic stimuli [108-110] in 3T3-fibro-blasts in response to various stimuli including bradykinin, thrombin and plateletactivating factor (PAF) [104] in endothelial cells responsive to bradykinin [111] and in FRTL-5 thyroid cells under stimulation by aradrenergic ligands [105]. In all... 

Acetylcholine, histamine glutamate, noradrenaline, serotonine vasopressin, thrombin thyrotropin releasing hormone odor, light... 

The inducers of these alterations range from certain proteolytic enzymes, in particular thrombin, to large molecules such as collagen, immune complexes, zymosan (alpha 41) and cationic polymers (alpha 28), and, finally, low molecular weight compounds such as adenosine-5-diphosphate (ADP), adrenaline, vasopressin, and serotonin. This wide variety of materials, all of them capable of eliciting the same result, suggests that.upon quite different stimuli of the plasma membrane, the same sequence of events is triggered off. These events can be subdivided by several criteria in different phases ... 

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