OBJECTIVE:
Apart from its anticoagulant properties, heparin has vasodilator and anti-inflammatory effects that could assist in the reversal of septic microcirculatory changes. This paper investigates the effects of heparin on endotoxemia-related microcirculatory changes and compares them to those observed with the use of recombinant human activated protein C.
METHODS:
After skinfold chamber implantation procedures and endotoxemia induction by intravenous Escherichia coli lipopolysaccharide administration (2 mg.kg-1), male golden Syrian hamsters were treated with intravenous unfractionated heparin (0.2 mg.kg-1). Intravital microscopy of skinfold chamber preparations allowed quantitative analysis of microvascular variables and venular leukocyte rolling and adhesion. Macrohemodynamic parameters were also analyzed. Endotoxemic hamsters treated with recombinant human activated protein C and non-treated animals served as controls.
RESULTS:
Heparin decreased lipopolysaccharide-induced leukocyte rolling and arteriolar vasoconstriction; it also increased survival when compared with non-treated animals, while recombinant human activated protein C decreased leukocyte adhesion. Administration of heparin plus recombinant human activated protein C was associated with a significant attenuation of lipopolysaccharide-induced capillary perfusion deficits.
CONCLUSIONS:
Heparin yields protective effects on endotoxemic animals' microcirculation. Those benefits were potentiated when heparin was administered in conjunction with recombinant human activated protein C.
KEYWORDS:
sepsis; endotoxemia; microcirculation; heparin; recombinant human activated protein C.
