Experimental Ulcer of the Colon in Rats.

Abstract

This work is part of a series of experiments to determine whether subcutaneous injections of Mercurochrome-220 Soluble (Hynson, Westcott and Dunning, Baltimore, Md., U. S. A.) rendered adult white rats more susceptible to the lethal effects of X-ray energy. On alternate days, 1.0 to 2.0 cc. of a 0.5% solution in normal saline was injected into the dorsal subcutaneous tissue of 12 adult rats, all of the same size. Different areas were selected for the successive injections to avoid a possible necrosis of the tissues from too concentrated and prolonged action of the stain. Thus each rat received a total of from 6.0 cc. to 8.0 cc. of this solution. Upon the 4th day, there was noticeable a distinct reddish tinge to the skin, ears, eyes, mucous membranes, and to the feces and urine as well. All of the animals were killed after the 4th injection; i. e., 7 days after the beginning of the experiment.

At autopsy, the connective tissues, fat, blood, skin and various organs of the digestive tract and of the urinary tract were distinctly stained with the dye, as has been reported by other investigators. 1

Upon microscopic examination, the kidneys presented histologic changes more marked in the glomeruli and in the cells lining the convoluted tubules. The vessels of the glomeruli and of the adjacent portions of the tubules were distended and filled with deeply stained red blood cells. The columnar lining of the convoluted tubules presented various stages of cloudy swelling, necrosis, and exfoliation. The most interesting and most constant of the histologic findings were referable, however, to the cecum and ascending colon.

Young and Hill 1 have reported colitis and enteritis present in animals receiving intravenous therapy, and, likewise, Todd 2 has recognized a form of catarrhal colitis.