Effect of sodium selenite on the ciliary activity, adenosine triphosphate, and protein synthesis in mouse trachea organ cultures

Trachea from albino mice were cut transversely into nearly identical rings and incubated in medium 199 with Hanks salts and HEPES buffer at 37 degrees C. Sodium selenite at 0.5-5 mM depressed the ciliary activity. With 1 and 5 mM sodium selenite, a 50% reduction in the activity index was observed after approximately 5 and 1.5 h, respectively. The ATP content in trachea rings was reduced with 0.05-5 mM sodium selenite, and increasing concentrations gave decreasing amount of ATP after incubation for 4 and 21 h. The rate of protein synthesis as determined by incorporation of radioactive leucine was reduced with 0.5 and 2 mM sodium selenite. The synthesis was reduced quickly by 2 mM sodium selenite, which gave a 30% reduction after incubation for 1 h. It seems that the ATP levels may be used as the most sensitive indication of sodium selenite toxicity in mouse trachea.