Quantitative studies on the accumulation of serum albumin and erythrocytes in mouse paw oedema induced by bradykinin or thermal injury.

The accumulation of 125I-labelled serum albumin and 51Cr-labelled erythrocytes was measured in mouse paw oedema induced by bradykinin or by heating the paw at 46.5 degrees. The extravasating fluid in bradykinin oedema consistently contained 50% of the albumin concentration of plasma, whereas the extravasating fluid induced by thermal injury initially had a low albumin content, but it progressively increased over a period of 30-40 min to equal albumin levels in plasma. Thermal injury also caused the extravascular accumulation of erythrocytes. Errors involved in attempting to measure the albumin content of the additional extravascular fluid in inflammation are discussed. Adrenaline suppressed bradykinin oedema, but potentiated thermal injury. These results do not support the view that bradykinin is the inflammatory mediator in thermally-induced oedema.