Rats were exposed to well-characterized aerosols of sodium sulfite, at levels ranging from 0.1 to about 15 mg/m3 and particle sizes of about 1 μm (mass median aerodynamic diameter). The responses of rats to breathing these aerosols for 3 days were evaluated by measurements of glycoprotein secretion rates by cultured tracheal explants from these rats, by measurement of protein, DNA, and RNA levels of lung homogenates prepared from these rats, and by quantitation of wet to dry weight ratios of right apical lung lobes from these rats. Increased rates of glycoprotein secretion were observed for trachea from rats exposed to 5 or to 15 mg/m3 of Na2SO3 aerosol, and increased wet to dry weight ratios of right apical lobes were also observed after exposure to these levels, as well as after exposure to 1 mg/m3 of Na2SO3 aerosol. Control experiments involving exposure to sulfate (Na2SO4) aerosol at 15 mg/m3 indicated that the observed effects were indeed due to exposure to the sulfite moiety. Exposure to aerosols of sodium hydroxymethane sulfonate (the product of addition of formaldehyde to sodium sulfite) aerosols (5 mg/m3) elicited less response in these assays than did exposure to sodium sulfite aerosol at the same concentration. We conclude that exposure of rats to well-characterized 1μm aerosols of sodium sulfite at concentrations equivalent to amounts of SO2 of about 0.2-2.7 ppm results in responses of the rats that may be conveniently evaluated when sensitive enough toxicological indexes are quantitated.
|Original language||English (US)|
|Number of pages||6|
|Journal||Toxicology and Applied Pharmacology|
|State||Published - 1980|
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