Experimental Pulmonary Edema. II Pathogenesis of Pulmonary Edema Caused by Ammonium Ion. ∗

Abstract

Koenig and Koenig 1 have described an acute pulmonary edema following the administration of ammonium salts to different species. It appears to be specifically a result of the ammonium ion. The occurrence and gross appearance of this edema resembles epinephrine induced pulmonary edema and in an effort to obtain information about the mechanism of the ammonium pathology a study has been made of its relation to edema due to epinephrine and adrenergic stimuli.

Experimental. Epinephrine induced pulmonary edema may be prevented by adrenergic blocking agents. 2 , 3 Their influence was observed upon ammonium pulmonary edema. Unfasted guinea pigs were divided into groups with the same sex distribution. All groups were lightly etherized to pass a stomach tube. Group 1, the controls, were given a sham dose of 10 cc water per kg body weight. All other groups received 1200 mg/kg of a 12% solution of NH4CI by oral gavage. Ten minutes before receiving the ammonium salt groups 3, 4 and 5 respectively received by intravenous injection in 1 cc saline/kg; 2 mg/kg of a B-haloethylamine, N-(9-fluorenyl) -N-ethyl-B-chloroethylamine-HCl (“SKF-501”); 2.5 mg/kg N-(2-chloroethyl)-N-ethylbenzhydrylamine-HCl (“SY-2”), which like “SKF-501” is an effective adrenergic blocking agent; and 1.5 mg/kg of the potent anttihistaminic N-B-dimethylaminopropylthiodiphenylamine - HCI (“Phenergao”, 3277 R.P.). The presence of pulmonary edema was determined at an autopsy by gross inspection and lung weight was used as a measure of its extent.

The summarized data comprise Table I. Group 1 was killed with ether while all of the animals in the other groups succumbed with convulsions 5-30 minutes after receiving the ammonium salt. The two adrenergic blocking agents and the antihistaminic all were without influence upon mortality. Since both of the adrenergic blocking agents completely prevented the ammonium edema but not the mortality, we may conclude that pulmonary edema need not be the cause of death fromtoxic doses of ammonium salts. The anthistaminic was without effect on the ammonium edema, which in this respect resembles the fulminating pulmonary edema due to epinephrine. 2