Utilization of 67Ga-citrate for the measurement of histamine-induced edema in anesthetized rats.

Radioactivity of the histamine-induced paw edema was measured after intravenous injection of 67Ga-citrate in anesthetized rats. The radioactivity was fluctuated almost parallel with the edema rate following subcutaneous injection of histamine. Both the radioactivity and the edema rate were almost equally reduced by pretreatment with chlorpheniramine, an antihistaminic agent. There was a good correlation between the edema rate and the radioactivity. These results suggest that 67Ga-citrate is useful for the pharmacological study of antiinflammatory drugs, or is available for measuring the vascular permeability.