The excretion of renal cells following necrosis of the distal segment of the nephron by hexadimethrine bromide.

The rate of excretion of renal cells was determined in rats with necrosis of the distal convoluted tubules and broad ascending limbs of the loops of Henle caused by injection of hexadimethrine bromide. The magnitude and the duration of abnormal cell excretion were correlated both with the dose of hexadimethrine and with the degree of damage that was evident on histological examination of the kidney. In general cell excretion studies provided a satisfactory indication of the degree of renal damage but the smallest lesions did not cause a significant increase in cell excretion and occasionally a rat with a very large lesion failed to show an increase in cell excretion rate. The changes in excretion rates observed in the present experiments were less than those found previously in animals with necrosis of proximal convoluted tubules caused by mercuric chloride. This is probably due firstly to the smaller number of cells in the distal nephron and secondly to the toxin causing disintegration of many of the cells. These findings have implications for the investigation of analgesic nephrotoxicity by measurement of urinary cell excretion rates. In order to appreciate the significance of increases in renal cell excretion following administration of various substances their site of action and the type of cell damage that they cause must first be established.