Development of an Acquired Resistance to Bichloride of Mercury by Renal Epithelium in Proximal Convoluted Tubule. ∗

Abstract

In previous publications 1-4 the fact has been established that when the epithelium of the convoluted tubules is sufficiently injured by uranium nitrate, a process of repair to this epithelial tissue may be inaugurated which results in the replacement of the damaged cuboidal cells by an atypical type of cell for this segment of the tubule. These cells are of a flattened order, imperfectly differentiated and with prominent, deeply staining nuclei. Such epithelial replacements not infrequently exist in the form of syncytial structures. An epithelial repair process of this type has been shown to impart to this segment of the tubule a resistance to subsequent injury by uranium nitrate. A fixed cell tissue resistance has been acquired in this segment of the tubule.

Some years ago the observation 5 was made during the study of the acute renal injury from bichloride of mercury that the predominant location in the kidney of the epithelial injury was the proximal convoluted tubule.

For several months 11 dogs have been available for study that have in past years effected a repair process to the proximal convoluted tubules as a result of a severe acute uranium injury which is characterized cytologically by the formation in this segment of the tubule of the atypical type of epithelial cell which has been previously described. All of these animals at different periods of their recovery have shown an acquired resistance on the part of this type of cell to secondary intoxications by uranium nitrate even when such intoxications were induced by an amount of this nephrotoxic agent 2 to 4 mg. per kilo in excess of the amount which induced an acute process of degeneration in the normal cuboidal cell of the proximal convoluted tubule.