Date of Award

2016

Degree Name

Biomedical Sciences

College

College of Science

Type of Degree

Ph.D.

Document Type

Dissertation

First Advisor

Gary O. Rankin

Second Advisor

Monica Valentovic

Third Advisor

Richard Niles

Fourth Advisor

Travis Salisbury

Fifth Advisor

Peter Harvison

Abstract

Chlorinated anilines have been used as important chemical intermediates in the production of a wide variety of pharmaceutical, industrial, and agricultural products. Exposure to chloroanilines can arise in both occupational and environmental settings and can lead to toxicity to multiple organs, including the kidney. Previous studies have established that of the mono- and dichlorinated anilines, 3,5-dichloroaniline (3,5-DCA) possesses the most nephrotoxic potential both in vitro and in vivo. However, little is known concerning the role of renal metabolism in nephrotoxicity. The studies presented in the following dissertation are the first to explore the toxicity, metabolism, and bioactivation of 3,5-DCA in isolated renal cortical cells (IRCC) obtained from male Fischer 344 rats, as well as to explore the nephrotoxic potential of putative 3,5-DCA metabolites. Results show that in IRCC, 3,5-DCA induced cytotoxicity in a concentration- and time-dependent manner. Further studies suggested that 3,5-DCA induced nephrotoxicity is due, at least in part, to bioactivation of 3,5-DCA to toxic metabolites via multiple enzyme systems. Additional studies suggested that CYP2C, FMO, and peroxidase metabolism of 3,5-DCA contributes to the bioactivation of 3,5-DCA to cytotoxic metabolites. In order to determine the ultimate toxic species, five putative metabolites were tested for their nephrotoxic potential. Of the five metabolites tested, only one, 3,5-DCAA was non-toxic. Further explorations were conducted to identify and quantify metabolites in IRCC after exposure to 3,5-DCA via HPLC analysis. The results of the HPLC studies show very little metabolism of 3,5-DCA in isolated renal cortical cells, which suggests that the ultimate toxicant is highly cytotoxic and most likely produced near its cellular target(s). However, the mechanism of 3,5- DCA induced cell death and cellular target remains to be determined.

Subject(s)

Biotransformation (Metabolism)

Cells -- Morphology.

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