Cyclophosphamide and inhibition of renal compensatory hypertrophy.

The objective of the present study was to determine whether cyclophosphamide inhibits nephrectomy-induced compensatory renal hypertrophy directly or indirectly owing to the reduced food intake caused by the drug. We measured kidney weight and renal water, protein, deoxyribonucleic acid (DNA), and ribonucleic acid (RNA) content and the renal RNA/DNA ratio in 72 rats distributed into groups as follows: left nephrectomized/cyclophosphamide-treated rats; left nephrectomized/saline treated rats; left nephrectomized rats submitted to food restriction and treated with saline; and left sham-nephrectomized rats treated with saline. An additional group of 12 rats was studied to obtain the initial values of the parameters. The parameters were also measured 1, 2 and 3 weeks after left nephrectomy or sham-operation. Cyclophosphamide was given once a week intraperitoneally at the dosage of 60 mg/kg body weight in saline. Corresponding volumes of saline were given to control animals. At the end of the 1st week all nephrectomized groups of rats showed some degree of renal compensatory growth. However, no significant differences in kidney weight, protein or RNA content were detected between controls, cyclophosphamide-treated rats, and animals submitted to food restriction at the end of the 2nd and 3rd week. We conclude that cyclophosphamide inhibits but does not abolish compensatory renal hypertrophy after uninephrectomy in the young rat and this inhibition is mediated primarily through the reduced food intake caused by the drug.