Passage of intratracheally instilled ultrafine particles from the lung into the systemic circulation in hamster.
The mechanisms of particulate pollution-related cardiovascular morbidity and mortality are not well understood. We studied the passage of radioactively labeled ultrafine particles after their intratracheal instillation. Hamsters received a single intratracheal instillation of 100 microg albumin nanocolloid particles (nominal diameter < or = 80 nm) labeled with 100 microCi technetium-99m and were killed after 5, 15, 30, and 60 min. In blood, radioactivity, expressed as percentage of total body radioactivity per gram blood, amounted to 2.88 +/- 0.80%, 1.30 +/- 0.17%, 1.52 +/- 0.46%, and 0.21 +/- 0.06% at 5, 15, 30, and 60 min, respectively. Thin-layer chromatography showed only one peak of radioactivity corresponding to unaltered (99m)Tc-albumin nanocolloid. In the liver, radioactivity, expressed as percentage of total radioactivity per organ, amounted to 0.10 +/- 0.07%, 0.23 +/- 0.06%, 1.24 +/- 0.27%, and 0.06 +/- 0.02% at 5, 15, 30, and 60 min, respectively. Lower values were observed in the heart, spleen, kidneys, and brain. Dose dependence was assessed at 30 min following instillation of 10 microg and 1 microg (99m)Tc-albumin per animal (n = 3 at each dose), and values of the same relative magnitudes as after instillation of 100 microg were obtained. We conclude that a significant fraction of (99m)Tc-albumin, taken as a model of ultrafine particles, rapidly diffuses from the lungs into the systemic circulation.
Nemmar
A
A
Laboratory of Pneumology, Center for Molecular and Vascular Biology, K.U.Leuven, Leuven, Belgium.
Vanbilloen
H
H
Hoylaerts
M F
MF
Hoet
P H
PH
Verbruggen
A
A
Nemery
B
B
D000393:Air Pollutants / Q000097:blood*; D000704:Analysis of Variance; D000818:Animals; D006224:Cricetinae; D005260:Female; D007278:Injections, Spinal; D008168:Lung / Q000378:metabolism*; D008297:Male; D019275:Radiopharmaceuticals / Q000097:blood*; D013668:Technetium Tc 99m Aggregated Albumin / Q000097:blood*; D014018:Tissue Distribution
D000393:Air Pollutants; D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin