The synthesis of PGs and relatives from membrane lipids, release of the finished products into the cytoplasm, and actions are summarized by Figure 16-5. Thus, when PG synthesis is stimulated in a cell, a fatty acid precursor, usually arachidonic acid, is released from the membrane lipids by phospholipase A2. It is acted on by the membrane PG synthetase complex, which produces a cyclic endoperoxide intermediate (Figure 16-4). This intermediate can give rise to PGE2, PGF2a, and PGI2 in cells that contain PGI2 synthetase or to TX and TXA2 in cells that contain TX synthetase (Figure 16-3). When homo-y-linolenic acid (20:3) (Figure 16-4) is the parent fatty acid, a different cyclic endoperoxide is produced. This intermediate can give rise to PGE! and PGFlu. Thus, the PGs or relatives occurring in a given cell depend on the precursor and
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Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.