THE EFFECTS OF SULFANILAMIDE ON THE LOWER VERTEBRATES

¹ Department of Pharmacology and Experimental Therapeutics, The Johns Hopkins University

1. A study of the effects of sulfanilamide on three lower vertebrates,—the fish, frog and chicken,—has been made. The drug appears to be most toxic for the fish, least toxic for the frog, on the basis of blood concentrations.

2. Absorption of sulfanilamide was found to vary depending on the route of administration.

3. Excretion of sulfanilamide in the lower vertebrates was slow corresponding to the small amount of glomerular filtrate in these animals.

4. Conjugation of sulfanilamide occurred in the fish and chicken but not in the frog.

5. Cyanosis was readily produced in the chicken by chronic intoxication with sulfanilamide.

6. Direct toxic action of sulfanilamide on the muscle of the frog was found. This was reproduced in vitro on isolated frog muscle.

7. With the exception of the fish, toxicity could only be demonstrated with blood levels of drug above the concentrations used therapeutically in man.