New aspects of heparin effects

The effects of a 5-day heparin treatment (10 kD, 64 IU/kg, intraperitoneally) on food-procuring behavior and spatial memory in a 12-arm radial maze were studies on Wistar rats. The maximum reinforcement scores in heparinized rats were attained by day 7 and in control rats only by day 16. In total, 75% heparinized and 45% control rats successfully learned the task for 24 days. On day 25 the contents of major transmitters and their metabolites in various brain structures and in the small intestine of control and experimental rats were determined. The rats treated with heparin showed increased concentrations of norepinephrine in the hypothalamus, homovanillic acid in the striatum, and serotonin in the small intestine. Our findings indicate that heparin exhibits a wide range of activities in addition to its anticoagulant effect.