Lung Retention in Mice exposed to Airborne Micro-organisms

Abstract

THE respiratory minute volume of mice can be obtained from Guy ton's¹ paper; but this does not tell us how much particulate material is retained in the lungs, a measurement of importance in calculating doses in respiratory infectivity experiments with micro-organisms. Harper and Morton² found a mean lung retention of 2.7 ml./min when mice weighing 20–22 g were exposed to clouds of single-cell particles of Bacillus globigiispores labelled with phosphorus-32. The exposure method used at thattime was unsatisfactory in that it involved considerable restriction of the mice by neck yokes. Later (1956, unpublished work) a few tests using less restrictive methods indicated a lung retention value of approximately 7.5 ml./min.