technetium-tc-99m-sulfur-colloid and Burns

The effect of injection or chronic infusion of lipopolysaccharide (LPS) into unanaesthetized rats on the distribution of [99Tcm-]SC has been determined. At a dose of 2.5 mg/kg, LPS injection caused a marked alteration in the distribution of the radiolabelled material, with more uptake being achieved in the lung while less was taken up by the spleen. Kidney and liver uptake were also changed. Chronic infusion of LPS at a similar dose (3 mg/kg in 24 h) caused a marked increase in the uptake of the radioactive material by the lung only. These data are consistent with a working hypothesis that the alterations in RES phagocytic activity of the lung observed in rats subjected to burn trauma could be related in part to LPS, either coming as a bolus, or being continuously presented.

Topics: Animals; Burns; Female; Lipopolysaccharides; Lung; Mononuclear Phagocyte System; Phagocytosis; Rats; Sepsis; Technetium Tc 99m Sulfur Colloid

The effect of platelet activating factor (PAF) injections on the uptake of 99mTc-SC (99mTc-SC (99mTc-sulphur colloid) was determined in vivo. PAF (2 micrograms) injected intravenously into unanaesthetized, unrestrained rats was associated with the development of lesions in the small intestine and alteration of 99mTc-SC uptake in vivo. 99mTc-SC uptake into the lung was increased while spleen uptake was decreased. Pretreatment of the animals with a PAF antagonist, SRI-64-441, prevented the intestinal lesions and alterations of 99mTc-SC uptake. Macrophages, isolated from lung lavage of the PAF-treated rats, demonstrated a decreased generation of hydrogen peroxide in vitro. The present results suggest that, in addition to its other effects on the immune system, PAF can also alter the in vivo phagocytic activity of the reticuloendothelial system in the rat.

Topics: Animals; Burns; Cecum; Disease Models, Animal; Injections, Intravenous; Intestine, Small; Mononuclear Phagocyte System; Necrosis; Platelet Activating Factor; Rats; Stomach; Technetium Tc 99m Sulfur Colloid

The role of haemolysis of blood in the alterations in the uptake of [99mTc]SC ([99mTc]-sulphur colloid) in vivo in the rat has been examined. When the haemolysed blood (produced by first freezing the blood in liquid nitrogen) was infused into synergenic Lewis rats via the tail vein, there was a significant reduction in the uptake of the [99mTc]SC by the spleen, but lung, liver and kidney uptake remained constant. These results suggest that haemolysis of the blood may play a role in the alterations in RES phagocytic activity observed in the spleen following thermal injury.

Topics: Animals; Burns; Female; Hemolysis; Mononuclear Phagocyte System; Phagocytosis; Rats; Rats, Inbred Lew; Spleen; Technetium Tc 99m Sulfur Colloid

The uptake of radiolabelled colloid or bacteria was compared in normal rats and animals subjected to acute burn trauma. The uptake of colloid by the liver was unaffected by burn trauma, but uptake of the labelled bacteria was reduced. Spleen uptake of both colloid and bacteria was reduced by burn trauma while lung uptake was increased. These data are consistent with the hypothesis that acute burn trauma alters reticuloendothelial system phagocytic activity in the rat towards both inert particles and live bacteria.

Topics: Acute Disease; Animals; Burns; Disease Models, Animal; Escherichia coli; Female; Liver; Lung; Mononuclear Phagocyte System; Phagocytosis; Rats; Spleen; Technetium Tc 99m Sulfur Colloid