Experimental nephritis in guinea-pigs by subcutaneous injections of chromates

Abstract

After having determined that I centigram of bichromate of potash is very nearly a lethal dose for guinea pigs of from 500-750 gm., forty guinea pigs were used in an effort to produce, if possible, lasting anatomic lesions in the kidneys by repeated injections. Great difficulty was encountered in continuing larger doses on account of the extensive necroses produced at the site of injection. In the end it was found that a 1/5-1/5 per cent. solution of chromate of potash to which an equal amount of carbonate of soda had been added was most satisfactory, although still quite irritating. As our experience has taught us that sublethal doses are most effective in experiments of this character, injections of one or one half centigram were used in one half of the experiments and the doses crowded as closely as the animals would tolerate; in other series smaller doses down to a quarter of a milligram were employed and continued for long periods (in one case for nearly two years). The immediate effect of the injection of large doses in the guinea pig is the production of an albuminuria which is usually quite limited in amount and the appearance in the sediment of desquamated cells from the uriniferous tubules, much more rarely of casts. The kidneys in the acute intoxication are very markedly hyperemic, there is more or less fatty degeneration and well marked necrosis and desquamation of the epithelium, later cast formation also occurs. The glomeruli are hyperemic, do not show any distinct histologic lesions. Hemorrhages from them mere not observed. The lesions are hardly severe enough to account for the early death of the animals. I have become rather strongly persuaded that the chromates cause death in guinea pigs not primarily by their action upon the kidneys, but in a different way, although nothing definite could be ascertained in this regard.