Effects of heparin and defibrinotide on malignant hypertension in rats.

This study examines the effects of anticoagulant and antithrombotic drugs on blood pressure (BP), plasma renin activity (PRA) and renal glomerular and vascular lesions in rats following aortic ligation. Whole heparin, low molecular weight (LMW) heparin or defibrinotide was administered for 4 weeks to rats following complete aortic ligation between the renal arteries. BP and PRA in whole heparin treated rats were significantly lower than those in control rats (p less than 0.01, p less than 0.01). Renal morphology also revealed a reduced number of epithelial cell droplets (ECD) (the nature of which is unknown) in glomeruli and less severe vascular lesions (p less than 0.005, p less than 0.005). Decreased BP and PRA were seen in rats receiving LMW heparin, but the failure of LMW heparin to prevent vascular damage indicates that an increased anti-Xa activity or reduction of PRA is not enough to prevent these lesions in hypertensive rats. The rats receiving defibrinotide showed reduced BP only.