EFFECTS OF BACTERIAL-ENDOTOXIN AND CORTICOSTEROIDS ON PLASMA-CONCENTRATIONS OF ALPHA-2 MACROGLOBULIN, HAPTOGLOBIN AND FIBRINOGEN IN RATS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 60  (4) , 434-440
Abstract
Bacterial [Escherichia coli] endotoxin [etox] injected into rats resulted in increased plasma concentration of .alpha.2-macroglobulin, haptoglobin and fibrinogen. Cortisone acetate injected i.m. alone was sufficient to increase plasma concentration of haptoglobin by 54% and to a lesser extent concentrations of the other 2 proteins. When cortisone acetate and/or cortisol succinate were injected simultaneously with varying doses of etox, the effects of the corticosteroid differed for each plasma protein. Doubtless because of the effect of cortisone by itself the slope of the dose-response relationship for haptoglobin was greatly reduced. The slope for .alpha.2-macroglobulin was reduced and that for fibrinogen was unaffected. If effects due to endogenous corticosteroids are to be avoided, increases in plasma fibrinogen may serve best as indicators of stimulation of the acute-phase response. Since relative increase of .alpha.2-macroglobulin due to the lowest dose of etox was much greater than that of fibrinogen, increases in concentration of the former protein represent the most sensitive indication of the acute-phase response. Consideration of the responses in individual rats has made possible division into those with more or less than average increases for all 3 plasma proteins and those showing irregular responses. In the group which received the lowest etox dose, a much larger number than would be expected on a random basis responded regularly with more or less than average increases for all 3 proteins.