Physiology 3140A Lecture 5: Other Lipid-Derived Chemical Mediators - Dr. Rylett
29 Nov 2016
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Document Summary
Most lipid-derived mediators are produced from phospholipids pi and pc by phospholipases. Best characterized by generation of inositol triphosphate (ip3) and diacylglycerol by phospholipase c- from pi. Other lipid mediators include: mediators with both autocrine and endocrine functions (i. e. prostaglandins and platelet-activating factor, autocrine: mediator that acts back on the cell that produced and released it. Acts as a positive/negative type of feedback. Cell release this along with other mediators that act on other cells. Positive feedback: when this acts on itself it tells them that their signaling is functioning properly & that it has taken place. Negative feedback: may tell them to stop signaling bc job is done. Large group of compounds including prostaglandins, thromboxanes, leukotrienes and prostacyclins stimulation of cell. Formed from essential fatty acid arachidonic acid: if diet is deficient of this, will have problems generating eicosanoids.
