Role of iron-binding proteins and enhanced capillary permeability on the accumulation of gallium-67.
We studied the role of the iron-binding proteins transferrin and lactoferrin and of increased capillary permeability on the accumulation of gallium-67 in rabbits. Intramuscular injection of histamine caused accumulation of gallium-67 (injected i.v. as citrate), and of Tc-99m DTPA, at the i.m. injection site. Normal saline and albumin did not. Intramuscular injection of transferrin or lactoferrin similarly caused Ga-67 uptake. No accumulation of Tc-99m DTPA was observed at the site of transferrin injection but there was a slight accumulation at the site of lactoferrin injection. Prior saturation of transferrin or lactoferrin with ferric ion abolished their effect on Ga-67 accumulation. Gallium-67, pre-bound to transferrin vitro, did not accumulate at the site of histamine or transferrin injection, but there was a slight accumulation at the lactoferrin site. Our results suggest that either increased capillary permeability or iron-binding progeins can cause local uptake of Ga-67. Since these factors are present at sites of inflammation, they may contribute to the accumulation of gallium in inflammatory lesions.
D000818:Animals; D002199:Capillary Permeability; D002352:Carrier Proteins / Q000494:pharmacology*; D005260:Female; D005710:Gallium Radioisotopes / Q000378:metabolism*; D006632:Histamine / Q000494:pharmacology; D007273:Injections, Intramuscular; D007501:Iron / Q000378:metabolism*; D007781:Lactoferrin / Q000494:pharmacology; D011817:Rabbits; D013997:Time Factors; D014168:Transferrin / Q000494:pharmacology
D002352:Carrier Proteins; D005710:Gallium Radioisotopes; D014168:Transferrin; D006632:Histamine; D007501:Iron; D007781:Lactoferrin