The Determination in Vivo of the Rate of Ciliary Beat in the Trachea

The rate of ciliary beat in the trachea of live rabbits was recorded by filming at 220 frames per second. The animals were able to breathe through their normal respiratory tracts, by a special connection between the microscope and the trachea. The mean rate from 31 subjects was 1,099 beats per minute, the deviation between the animals 172 beats per minute, and the error of method 40 beats per minute. The rate of beat was correlated to the rectal temperature, but did not show any variation during the two hours the experiments lasted. The method can be used for investigations into the effects of inhaled agents (gases, particles) on the ciliary activity of the trachea.