Abstract

Two-year feeding of 0.5 and 1.0% dietary levels of diphenylamine (DPA) to male and female albino rats caused growth arrests which were partly due to lowered food intakes. The females' growth was slightly arrested at 0.1%, an effect apparently due to DPA itself. Any such effect at 0.1% on the males could have been obscured by the greater deviations of their weights from their mean weights than the deviations of the females' weights. Moderate degrees of anemia resulted from prolonged ingestion of 0.5 and 1.0% concentrations of the compound, but prompt recoveries of hemoglobin followed feeding of the control diet. Leukocyte numbers and percentages remained within normal ranges. DPA did not increase proteinuria or cause glycosuria. It is highly probable that apparent decreases in litter sizes and numbers of pups weaned were largely due to inadequate food intakes by their gestating and lactating mothers fed dietary DPA. The significantly decreased weights of the pups, at weaning, in but one of the nine experimental dietary categories was probably due to the same cause. The 2-year ingestion of DPA caused lesions only in the urinary tract, namely, cystic dilatation of renal tubules with interstitial inflammation. Glomeruli were never altered. Lower tubules were sometimes filled with a proteinaceous fluid, and at other times with a blood-derived pigment. These accumulations were in some cases found in the renal pelvis or bladder, accompanied by mild epithelial hyperplasia or squamous metaplasia. The break-point for the occurrence of cystic change lies in the region of the 0.1% dietary concentration; and that for chronic nephritis, between 0.1 and 0.5%. The incidence of tumors was due to the senility of the rats at autopsy, not to treatment. When DPA is properly used for apple scald control, a very wide margin of safety exists.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call