A Study of the Toxicity of the Protamine, Salmine*

The protamine, salmine, has become widely known in the combined form, protamine-insulin. It has been generally assumed that the protamines are non-toxic. Vartiainen and Marble (1941) found that the median lethal dose of salmine subcutaneously in mice and rabbits was 200-300 mg./kg. and concluded that it was non-toxic in ordinary doses-a view supported by its widespread clinical use with no allergic or other side-actions. Reiner, de Beer, and Green (1942) found an LD50 of 94 mg./kg. in mice with protamine (presumably salmine ?). Ahlstrom and von Euler (1946) have reported essentially similar results with rats and guinea-pigs, using salmine and also the related protamines, clupein and scombrin.