Abstract
The effects of protamine sulfate and lactoferricin (LFC) on the anticoagulant action of sodium heparin in mouse whole blood were investigated. Also, the influences of these drugs on coagulation of whole blood and on the relative abundance of various blood cells were assessed.
Lactoferrin (LF) at high doses antagonized the anticoagulant action of sodium heparin. Both protamine sulfate and LFC strongly antagonized the anticoagulant action of sodium heparin. No large difference between the potency of protamine sulfate and that of LFC was observed. LFC did not affect the anticoagulant action of sodium citrate. Protamine sulfate suppressed blood coagulation with potency almost equal to that of protamine. LFC also displayed this anticoagulant action. Its potency, however, was less than that of protamine. Protamine induced a reduction in the relative abundance of platelets and an increase in the apparent numbers of white blood cells. LFC induced a similar alteration in numbers of blood cells, but its potency was much less than that of protamine.
These results suggest that the domain of LF responsible for its antiheparin action is region corresponding to LFC. The antiheparin action of LFC is almost equipotent to that of protamine sulfate. However, the side effects of LFC, such as the anticoagulant action and the alteration of blood cell counts, are possibly less than those of protamine when the drug is used for the neutralization of heparin.
