[Mechanism of 67Ga uptake by an experimental abscess--permeability of plasma from blood vessels in abscessed tissue].

In the previous paper, we reported that 67Ga was accumulated in abscess and uptake rate of 67Ga in abscess increased with time after the injection of 67Ga-citrate. The present study was undertaken to elucidate the influence of blood flow on the accumulation of 67Ga in abscess. Five days after subcutaneous injection of 0.2 ml of turpentine to the rats, 131I-human serum albumin (HSA) was injected intravenously to the rats. At an appropriate time after the injection (10 min to 6 days), uptake rates of 131I-HSA in abscess and normal tissues were measured. Similarly, 51Cr-red blood cells (RBC) were injected intravenously to the above rats and the uptake rates of 51Cr-RBC were also measured. One, three, and 24 hours after injection of 131I-HSA, the uptake rates of 131I-HSA in abscess were 1.32 %dose/g, 1.84 %dose/g, and 0.82 %dose/g, respectively. However, the uptake rates of 51Cr-RBC in abscess was very small, and the value was 0.14 %dose/g at 24 hours after the injection. In the case of abscess, blood in the tissue fluid was very little, but the permeability of 131I-HSA from the blood vessel in the tissue was much larger than that of normal tissues. From these facts, it was deduced that the accelerated permeability caused the abscess accumulation of 67Ga.