Lesions produced in rabbits by repeated intravenous injections of living colon bacilli

Abstract

Of a series of rabbits injected intravenously with a strain of colon bacillus every 3 or 4 days over considerable periods, the 7 animals which withstood this treatment longest, namely 88, 98, 102, 113, 115, 116, and 142 days, showed pronounced lesions in the kidneys, spleen, and liver. In the kidneys there is produced a hyaline and fibrous thickening of the vascular loops of the glomeruli with the formation of hyaline bodies in the tufts and occasional adhesions between the tufts and glomerular capsules. The tubular epithelium shows more or less degeneration and many casts are present in the tubules. The interstitial connective tissue shows a beginning cellular thickening, apparently not due to the spontaneous nephritis frequently seen in rabbits. The livers show in certain cases central necroses with hyaline degeneration of the liver cells about these areas and elsewhere. In two cases there is deposited between the rows of liver cells in the middle and peripheral portions of the lobules a homogeneous amyloid-like substance. The livers in all cases show a more or less marked cellular increase of the periportal connective tissue—the latter possibly a spontaneous lesion. The spleens show a fibrous thickening of the reticulum of the pulp with some hyaline formation. The most striking lesion is a formation of connective tissue with much amyloid-like material about the peripheries of the Malphigian bodies, in cases almost replacing these structures. The appearance of the homogeneous substance described and its distribution naturally suggest amyloid. Attempts to produce the typical staining reactions of this substance failed however, possibly owing to the fact that the material had unfortunately been fixed in Orth's fluid before the attempt was made.