Effects of Gaseous Ions on Tracheal Ciliary Rate. ∗

Abstract

Recent experiments have shown that + and − air ions have marked effects on ciliary rate and other properties of the mammalian trachea, both in vitro(3) and in vivo (4). It seems reasonable to conclude that these effects stem from physiologically significant alterations in state of gases present in ambient atmosphere and that deliberately produced changes in composition of this atmosphere would be reflected in the response of the tracheal tissue. The following experiments were performed to test this assumption.

Methods. Anesthetized rabbits were tracheotomized and placed in humid-air ionizing chamber according to technic already described (4). Gases used were warmed to 25-28°C, bubbled through water, and blown continuously into the chamber. Since earlier work(2) had shown that presence of smog or cigarette smoke in ambient atmosphere altered the action of air ions on bacterial suspensions, cigarette smoke was employed in some of these experiments. It was produced in mechanical device operating under negative pressure, and then treated in the same way as gases. For N₂ and CO₂ experiments it was necessary to sacrifice the rabbits with an overdose of nembutal; experiments with O₂ and cigarette smoke permitted exposure of living as well as sacrificed animals. As in previous work(1-4): (a) ions were generated by β radiation from sealed tritium foils, a rectifying circuit allowing selection of + or − ions, (b) the same stroboscopic method was employed to determine rate of ciliary beat (accuracy ± 50 beats/min.), and (c) atmospheric temperature in exposure chamber varied from 25-28°C on different days, while relative humidity remained close to 90%.

Results. When administered in unmodified humid air, − air ions increase ciliary rate by about 200 beats/min (reaching maximum effect within 10-20 minutes), while + air ions lower ciliary rate by about 300 beats/min or abolish ciliary activity altogether (reaching maximum effect within 15-20 minutes).