Nicotine Inhibits Anticoagulant Actions of Heparin

Abstract

The lipid-clearing, anticoagulant actions of heparin, a sulfated mucopolysaccharide, can be inhibited by nicotine, according to Dr. Harold J. White of the Veterans Administration Hospital in Roxbury, Mass. In a paper "The Antagonism Between Nicotine and Heparin Activity," White observed that in white rats, injected with nicotine followed by heparin (and in reverse order), the normal lipid-clearing action of heparin decreased. In addition, the presence of nicotine inhibited the anticoagulant qualities of heparin, he said. When added to the blood, nicotine both accelerated (when present in minute amounts) and prolonged (when present in larger amounts) the normal clotting time. The accelerating effect could be reversed by prior incubation of nicotine with heparin. White's two-part study proceeded along these lines: <h3>In vitro.—</h3> Post-heparinized rat plasma (.5 ml) was incubated for one hour with varying amounts of nicotine in a commercial emulsion. The clearing factor activity (CFA) was measured as optical density