Physiology 3140A Lecture Notes - Lecture 24: Cytosol, Prednisone, Cyclooxygenase
28 Dec 2017
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Second messenger and mediators derived from membrane lipids. Glycerophospholipids have 2 fa (on c1, c2 of glycerol backbone, c3 is phosphate head group: arachodonic acid is the fa most commonly found on c2, cleaved by phosolipase a2 and is a lipid mediator. Best characterized is generation of inositol triphosphate (ip3) and diacylglycerol by have issues with pkc activation) phospholipase c- from pi. Inflammatory vs. anti-inflammatory, dilation vs. constriction: clinical situations: measure prostaglandin concentration in blood. In parturition, the prostaglandin content goes up in the uterus before contractility initiates birth process. Large group of compounds including prostaglandins, thromboxanes, leukotrienes and prostacyclins: within each category, there are families of molecules, arachodonic acid is the starting point. Arachidonic acid is not free in the cell. In the cell it is esterified to membrane lipids: do not find a free pool of arachidonic acid sitting in cells because it can be metabolized to biologically active eicosinoids.
