[Studies on temporal distribution and its influences in the mouse after intravenous injection of magnetic ferrite particles].
We undertook an experimental study on the tissue distribution of ferrite and its injurious effect on mice organs at various time points after intravenous administration. The tissue distribution of ferrite was observed by autoradiography. Furthermore, sample radioactivity counting was done for blood and main organs, such as the heart, lung, liver, kidney, and spleen. Further, biochemistry studies and light and transmission electron microscopic studies were carried out. 1) After intravenous administration of radioactive ferrite, the radioactivity was distributed in organs and tissues as follows. i. The autoradiograms showed increased uptake of radioactivity in the lungs and liver. The uptake of radioactivity in the lungs was the highest immediately after dose administration and declined with time thereafter. In the liver, on the other hand, there was increased uptake 1 hour after dose administration, without showing any appreciable decrease with time thereafter. ii. Tissue uptake of radioactivity as determined by the sample counting method was the highest in the lungs of all organs at 30 to 60% of total dose, and the liver ranked second at 14 to 35%. In other organs, tissue uptake of radioactivity was minimal, ranging from 0.1 to 1.4%. In time the tissue radioactivity levels were such that the lungs showed the highest increase immediately after dose administration, with a subsequent gradual decrease, while the liver showed a gradual increase with time. The accumulated uptake of radioactivity per gram of tissue was the highest in the lungs of all organs. The temporal change of tissue radioactivity levels was such that the spleen tended to show an increasing uptake with time. One week after dose administration, the spleen showed about the same uptake as the liver. 2) The injurious effects that radioactive ferrite exerted on organs and tissues after intravenous administration are as described below. i. Biochemistry studies indicated that the treated animals had slight hepatic function impairment at 1 and 3 months after dose administration. On the other hand, there was no remarkable change in their renal function. Serum levels of Fe showed little change throughout the study. ii. Examination under LM (light microscope) and TEM (transmission electron microscope) revealed ferrite deposition in the lungs throughout the study. In light micrographs, there was a slight degenerative change in the alveolar wall in the lungs at 1 day after dose administration, but it was recovered in 1 week. On the electron microscopic level, the tendency was similar to that of the lungs.(ABSTRACT TRUNCATED AT 400 WORDS)
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D000818:Animals; D005290:Ferric Compounds / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006651:Histocytochemistry; D007275:Injections, Intravenous; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008280:Magnetics; D008297:Male; D051379:Mice; D014018:Tissue Distribution
D005290:Ferric Compounds; C001215:ferrite