title: Hyperbilirubinemia's protective effect against cisplatin nephrotoxicity in the Gunn rat.
abstract: Gunn rats, deficient in the enzyme uridine diphosphate glucuronyl transferase, were used to investigate the effects of unconjugated hyperbilirubinemia in cisplatin nephrotoxicity. The effect of bilirubin on the antineoplastic activity of cisplatin in osteosarcoma cell lines was also determined. The in vivo model involved three groups of rats (n=6 rats/group): homozygous Gunn rats (j/j), heterozygous Gunn rats (j/+), and congenic Wistar rats. On day 0, all rats were given 4 mg/kg cisplatin intraperitoneally. Blood was sampled on days 0, 3, and 5 for bilirubin, BUN, and creatinine and kidneys were taken on day 5. Cell culture was performed in four canine osteosarcoma cell lines using the average concentrations of bilirubin for homozygous Gunn rats at day 0 and 3. Bilirubin was added to cell lines alone and with cisplatin. Cell viability was assessed using the CellTiter Blue assay. Serum bilirubin levels were highly elevated in Gunn j/j, moderately elevated in Gunn j/+, and undetectable in Wistar rats at day 0. Bilirubin provided a nephroprotective effect, with significantly lower BUN and creatinine in Gunn j/j when compared with Wistar rats at day 5. Histological grading demonstrated preservation of the S3 segment in Gunn j/j when compared with Wistar rats (P<0.05). Bilirubin had no significant effect on the antineoplastic effect of cisplatin at either concentration in the four cell lines (P<0.001). Hyperbilirubinemia in the Gunn rat provided marked preservation of renal function and histology in a cisplatin nephrotoxicity model. Exogenous bilirubin did not interfere with the antineoplastic activity of cisplatin in vitro.
authors.affiliation: College of Veterinary Medicine, Department of Small Animal Clinical Sciences, University of Florida, Gainesville, Florida 32610-0126, USA.
authors.forename: Karri
authors.initials: K
authors.lastname: Barabas
authors.forename: Rowan
authors.initials: R
authors.lastname: Milner
authors.forename: James
authors.initials: J
authors.lastname: Farese
authors.forename: Chris
authors.initials: C
authors.lastname: Baylis
authors.forename: Byron
authors.initials: B
authors.lastname: Croker
authors.forename: Linda
authors.initials: L
authors.lastname: Archer
authors.forename: Christopher
authors.initials: C
authors.lastname: Adin
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D000818:Animals; D000970:Antineoplastic Agents / Q000009:adverse effects*; D001663:Bilirubin / Q000097:blood* / Q000494:pharmacology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood; D004285:Dogs; D006932:Hyperbilirubinemia / Q000378:metabolism*; D007274:Injections, Intraperitoneal; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008297:Male; D051381:Rats; D011911:Rats, Gunn; D017208:Rats, Wistar
chemical_list: D000970:Antineoplastic Agents; D003404:Creatinine; D002945:Cisplatin; D001663:Bilirubin