Studies on Heparin Metabolism in Hemostatically Different Dogs^[*]

Summary

1. The problem of different hemostatic response of dogs to an injected standard dose (300 u/kg) of heparin was studied, trying to detect differences in the metabolism of this mucopolysaccharide.

2. The rate of disappearance of heparin from circulation seems to be the same in either heparin-labile or heparin-resistant dogs, as measured by clotting time determinations in whole blood and microelectrophoresis densitometry, after heparin extraction.

3. A difference in the renal excretion of heparin was found between HL and HR dogs. These dogs eliminate a larger amount of heparin than the others in the first 30 min after injection. This difference is significant for p < 0.02.

4. Chemical analyses were done trying to detect a heparin depot in kidneys, lungs, hind limb skin, heart, aorta, vena cava and femoral vessels. Heparin was not detected in these tissues.

5. There is not a different protein binding of heparin between HR and HL dogs, as judged by microelectrophoresis of whole plasma concentrated by lyophilization.

^* Aided by a grant 1RO5TW-00114-01-Al from National Institutes of Health, U. S. A.

^** Fellow “Conselho Nacional de Pesquisas”, Brasil.

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