Tolerance and Initial Metabolic Response to Ammonia Intoxication in Selected Bats and Rodents

Abstract

Metabolic rates, as measured by oxygen consumption, and tolerances of three bats, Tadarida brasiliensis, Myotis lucifugus , and Eptesicus fuscus , and the laboratory rat, Rattus , and mouse, Mus , were determined in increasingly concentrated ammonia in air mixtures. Rats and mice exhibited increased oxygen consumption when exposed to increased ammonia levels. Oxygen consumption in rats ranged from 0.8 to 1.2 cc/g/hr in environmental gradients ranging from normal air to 5000 parts per million ammonia (ppm ammonia), while mice exhibited a rise in oxygen consumption from 3.7 to 4.7 cc/g/hr in concentrations of 0–3000 ppm ammonia. Myotis lucifugus exhibited erratic responses in mixtures of 0–5000 ppm ammonia, and oxygen consumption fluctuated between 4.9 and 10.6 cc/g/hr. Similarly, in E. fuscus consumption fluctuated from 3.3 to 7.2 cc/g/hr in 0–7000 ppm ammonia. In neither species was oxygen consumption correlated to the change in ammonia concentration. Tadarida brasiliensis exhibited decreased oxygen consumption ranging from 8.8 cc/g/hr to 2.3 cc/g/hr in air containing 0–7000 ppm ammonia. Tadarida brasiliensis and E. fuscus lived for 2½ and 1½ hrs, respectively, when exposed to 7000 ppm ammonia, but for only 10–20 min at 10,000 ppm ammonia. Myotis lucifugus and laboratory rats lived for 30–45 min in 5000 ppm ammonia. Laboratory mice lived for 2½ hrs at 3000 ppm and 10–20 min at 5000 ppm ammonia.