title: Deposition and retention of 0.1 micron 67Ga2O3 aggregate aerosols in rats following whole body exposures.
abstract: Determinations were made of respiratory tract deposition and gastrointestinal tract burdens following whole body inhalation exposures, typical of those used in many chronic exposures; these were compared to values obtained in nose-only exposures. Fischer-344 rats were exposed in large volume chambers, in a whole body mode, to 0.1 micron volume median diameter (VMD) 67Ga2O3 particles 5 hrs/day. Deposition per unit of exposure time and retention were essentially identical following either 1 or 3 day exposures. The lung deposition of particles was 2.8 units/hr for males and 2.2 units/hr for females if the exposure concentration was expressed as 1 unit/L. These values represent a deposition of approximately 15% of the inhaled particles, similar to values obtained for nose-only exposures. Aerosol deposition per kgm body weight was 24% higher in females than males. Passage of material into the gastrointestinal tract was 1.6-fold greater for these whole body exposures as compared to nose-only exposures to the same aerosol mainly resulting from extra material ingested by grooming of the pelt. Approximately 60% of the pelt burden was calculated to be ingested following whole body exposures.
mesh_terms: D000336:Aerosols; D000818:Animals; D001273:Atmosphere Exposure Chambers; D001822:Body Burden; D005260:Female; D005708:Gallium / Q000378:metabolism*; D005710:Gallium Radioisotopes; D008297:Male; D010316:Particle Size; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D000336:Aerosols; D005710:Gallium Radioisotopes; C038863:gallium oxide; D005708:Gallium