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JAMA. 1941;116(26):2831-2835. doi:10.1001/jama.1941.02820260005002.
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The use of heparin as prophylactic against thrombosis has arisen through our increased knowledge of this substance gained during the last few years. The latest developments in this field have been reviewed in two monographs of recent date.1 The chemical nature of heparin is known. Being a mucoitin polysulfuric acid with not less than about 40 per cent of sulfuric acid, the heparin polysaccharide possesses an exceedingly high negative electric charge which enables it to react with some of the components of the coagulation system, preventing the coagulation of the blood. In the body it functions like a hormone, lessening the coagulability of the blood. Like other hormones, it is produced by a special kind of cells, the mast cells of the connective tissue, known to be located mainly in the neighborhood of the smaller blood vessels. The metachromatic granules of these cells consist of heparin. From these cells


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