How does adenosine diphosphate (ADP) activate platelets Essay

How does adenosine diphosphate (ADP) activate platelets - Essay Example ADP induces platelet shape change, calcium flux, and inhibition of adenylyl cyclase, leading to aggregation. Kahner et al. (2006) also stated that rapid shape change, release of granular contents, generation of lipid mediators, and aggregation occur during platelet activation. Various surface receptors involved in platelet activation include G protein coupled receptors (GPCRs), integrins and glycoprotein receptors. Adenosine diphosphate (ADP) (released from platelet granules) and thromboxane A2 (generated within platelets) are the secondary mediators that activate other resting platelets, resulting in the amplification of initial physiological haemostatic response. Adenosine nucleotides are released following platelet activation signal through the P2 purinergic receptors on the platelet membrane. The two types of P2 receptors are ligand-gated cation channels (P2X), or GPCRs (P2Y). Till date, seven different P2X receptors (P2X1)) and eight distinct P2Y receptors (P2Y1,2,4,6,11-14) hav e been identified which were cloned from mammalian tissues. P2Y1, P2Y12, andP2X1 subtypes are the P2 purinergic receptors expressed on platelets and their physiologic agonists are ADP, ADP, and adenosine triphosphate (ATP), respectively. These receptors, when activated by the agonists, initiate a complex signaling cascade that ultimately results in platelet activation and thrombus formation. The physiological agonist for the P2Y1 receptor is ADP. This receptor can also be stimulated in vitro by 2MeSADP, ADP, APDaS and ADPbS in the decreasing order of potency and is involved platelet shape change and aggregation brought about by ADP. P2Y12 is coupled to Gi2 protein. Upon stimulation, the Ga and Gbc subunits of the heterotrimeric G protein dissociate and activate various signaling pathways. The Gai2 is found to be responsible for ADP-mediated inhibition of adenylyl cyclase and subsequent reduction in cytosolic cAMP concentrations. This is one

Management Information Systems Essay Example | Topics and Well Written Essays - 4000 words

Management Information Systems - Essay Example The essay "Management Information Systems" talks about the development of a new system for the ABC Company. This company is computer hardware manufacturer that carry out product for larger scale orders. The overall management and handling of such huge orders are difficult through the manual order processing approach.This information system will be used as an information management system of the overall organizational data. This system will conduct an online transaction and store the dealing and transaction data on the company’s central database. After that this data will be used to access the overall sales analysis. We will derive monthly or periodic report for the analysis of the overall business position. This system will facilitate in managing the overall products sales and deals regarding the corporate online transactions. Here we will be able to access and retrieve the overall quality of the stock and its current level because in any online transaction the stock status is really necessary for the handling of dealing. This product and stock information will provide a great facility for stock management. Here we will assign a product code to each project and through that code, we will easily retrieve the product information for the better management of the stack. This system will be an online system. We will create an organizational management module. This module will facilitate only to organizational executives to view, manage and handle online products, stock, sales and other organizational information.