AJP - Heart and Circulatory Physiology, Vol 253, Issue 1 58-H65, Copyright © 1987 by American Physiological Society
Increased vascular resistance during complement-activated plasma infusion in swine
L. J. Swenson, G. A. Pantely, C. G. Anselone and J. D. Bristow
To investigate the acute effects of complement activation on blood flow, we
infused complement-activated plasma into the femoral artery of the isolated
hindlimb of 19 anesthetized swine. Femoral artery blood flow decreased
abruptly, was lowest at 1 min of the infusion, and thereafter slowly
increased despite continued infusion. There was no significant change in
femoral artery pressure or femoral vein pressure, confirming an acute
increase in vascular resistance. Control infusion of
heat-decomplemented-activated plasma caused no change in pressure or flow.
Slope of the femoral artery pressure-flow relationship during maximal
vasodilation with adenosine was significantly lower after infusion of
complement-activated plasma, confirming a persistent increase in vascular
resistance. Neither the acute nor the persistent increase in vascular
resistance was prevented by alpha-adrenergic blockade with phentolamine or
granulocytopenia produced by cyclophosphamide. We conclude that
complement-activated plasma infusion in the femoral circulation causes an
abrupt increase in vascular resistance that persists during
pharmacologically maximal vasodilation, is not due to alpha-mediated
vasoconstriction, and is not altered by severe granulocytopenia.
