Histopathology and Cell Proliferation Induced by 2,2,4-Trimethylpentane in the Male Rat Kidney

Abstract

Unleaded gasoline causes acute and chronic nephrotoxicity and renal tumors in male rats, but not female rats or mice of either sex. An active nephrotoxic component of unleaded gasoline has been identified as 2,2,4-trimethylpentane (TMP). The first objective of this study was to characterize light microscopic renal lesions induced in male F344 rats by a 21-day gavage regimen of 50 to 500 mg/kg TMP. The second objective was to localize and quantitate sites of renal cell proliferation induced by the same TMP dose regimens using histoautoradiographic analysis after [³H]thymidine incorporation. Light microscopic lesions in the proximal convoluted tubule consisted of protein droplet and crystalloid body accumulation, degeneration, and necrosis, and were similar to lesions noted in previous inhalation and gavage studies with other hydrocarbon compounds. The above renal lesions were not dose-related, although tubular dilation of thin limb segments with granular cell debris was dose-related. In cell proliferation studies TMP induced a non-dose-related five- to sixfold increase in the labelling index of the same proximal convoluted tubule portions (P₂ segment) that contained severe crystalloid body accumulation, degeneration, and necrosis. Less pronounced, but statistically significant (p ≤ 0.05), increases in cell proliferation were also observed in other nephron segments, indicating a generalized regenerative response of the kidney to TMP. The cytotoxic and regenerative renal effects of TMP administered by gavage suggest that similar mechanisms may be involved in the induction of kidney tumors in male rats following chronic inhalation exposure to unleaded gasoline.

References

1. Alden CL , Kanerva RL , Ridder G , and Stone LC (1984). The pathogenesis of the nephrotoxicity of volatile hydrocarbons in the male rat. In: Renal Effects of Petroleum Hydrocarbons, MA Mehlman (ed). Princeton Scientific Publishers, Inc., Princeton, New Jersey, pp. 107–120.

2. Bennet HS , Wyrick AD , Lee SW , and McNeel JH (1976). Science and art in preparing tissues embedded in plastic for light microscopy with special reference to glycol methacrylate, glass knives, and simple stains. Stain Technology 51: 71–97.

3. Borriston Project Number 1707. (1984). Serial sacrifice with unleaded gasoline in rats. Light microscopy pathology summary. Experimental Pathology Laboratories, Inc.

4. Busey WM and Cockrell BY (1984). Non-neoplastic exposure-related renal lesions in rats following inhalation of unleaded gasoline vapors. In: Renal Effects of Petroleum Hydrocarbons, MA Mehlman (ed). Princeton Scientific Publishers, Inc., Princeton, New Jersey, pp. 57–64.

5. Cain H , Egner E , and Redenbacker M (1977). Increase of mitosis in the tubular epithelium following intrarenal doses of various kidney homogenates and homogenate fractions in the rat. Virchows Arch. Abt. B Cell Pathol. 22: 55–60.

6. Conaway CC , Schreiner CA , and Cragg ST (1984). Mutagenicity evaluation in petroleum hydrocarbons. In: Applied Toxicology of Petroleum Hydrocarbons, MA Mehlman (ed). Princeton Scientific Publishers, Princeton, New Jersey, pp. 89–108.

7. Cuppage FE and Take A (1967). Repair of the nephron following injury with mercuric chloride. Am. J. Pathol. 51: 405–410.

8. Cuppage FE , Chiga M , Take A (1972). Cell cycle studies in the regenerating rat nephron following injury with mercuric chloride. Lab. Invest. 26: 122–129.

9. Doull J, Bridges BA, Kroes R, Golberg L, Munro IC, Paynter OE, Pitot HC, Squire R, Williams G, and Darby W (1983). The relevance of mouse liver hepatoma to human carcinogenic risk. A report of the International Expert Advisory Committee to the Nutrition Foundation. The Nutrition Foundation, Inc., Washington, D.C.

10.

10. Gray JE (1977). Chronic progressive nephrosis in the albino rat. CRC Crit. Rev. Toxicol. 5: 115–144.

11.

11. Haagsma BH and Pound AW (1980). Mercuric chloride induced tubulonecrosis in the rat kidney: The recovery phase. Br. J. Exp. Pathol. 61: 227–241.

12.

12. Halder CA , Warne JM , Hafoum NS (1984). Renal toxicity of gasoline and related petroleum naphthas in male rats. In: Renal Effects of Petroleum Hydrocarbons, MA Mehlman (ed). Princeton Scientific Publishers, Inc., Princeton, New Jersey, pp. 73–88.

13.

13. Hard GC (1975). Autoradiographic analysis of proliferative activity in rat kidney epithelial and mesenchymal cell subpopulations following a carcinogenic dose of dimethylnitrosamine. Cancer Res. 35: 3762–3773.

14.

14. Kitchen DN (1984). Neoplastic renal effects of unleaded gasoline in Fischer 344 rats. In: Renal Effects of Petroleum Hydrocarbons, MA Mehlman (ed). Princeton Scientific Publishers, Inc., Princeton, New Jersey, pp. 65–71.

15.

15. Laurent G , Maldague P , Carber MB , and Tulkens PM (1983). Increased renal DNA synthesis in vivo after administration of low doses of gentamicin to rats. Antimicrob. Agents Chemother. 24: 586–593.

16.

16. Laurent G , Toubeau G , Maldague P , Carber MB , Henson-Strenron JA , and Tulkens P (1984). Tubular regeneration in rat kidney cortex during treatment with gentamicin at low dose. Arch. Toxicol. Suppl. 7: 459–463.

17.

17. MacFarland HN (1984). Xenobiotic induced kidney lesions: Hydrocarbons. The 90-day and 2-year gasoline studies. In: Renal Effects of Petroleum Hydrocarbons, MA Mehlman (ed). Princeton Scientific Publishers, Inc., Princeton, New Jersey, pp. 51–56.

18.

18. Maunsbach AB (1966). Electron microscopic observations of cytoplasmic bodies with crystalline patterns in rat kidney proximal tubule cells. J. Ultrastruct. Res. 14: 167–189.

19.

19. Maunsbach AB (1973). Ultrastructure of the proximal tubule. In: Handbook of Physiology, Section 8: Renal Physiology, J Orloff (ed). American Physiological Society, Washington, D.C., pp. 31–81.

20.

20. Oliver J , MacDowell M , and Lee YC (1954). Cellular mechanisms of protein metabolism in the nephron, I. The structural aspects of proteinuria, tubular absorption, droplet formation, and the disposal of proteins. J. Exp. Med. 99: 589–604.

21.

21. Peto R , Pike MC , Day NE , Gray RG , et al (1980). Guidelines for simple, sensitive significance tests for carcinogenic effects in long term animal experiments. In: Long Term and Short Term Screening Assays for Carcinogenesis: A Critical Appraisal. IARC Monographs, Suppl 2, Lyon, pp. 311–391.

22.

22. Phillips RD and Cockrell BY (1984). Effects of certain light hydrocarbons on kidney function and structure in male rats. In: Renal Effects of Petroleum Hydrocarbons, MA Mehlman (ed). Princeton Scientific Publishers, Inc., Princeton, New Jersey, pp. 89–105.

23.

23. Porter GA , Laurent G , Maldague P , and Tulkens P (1984). Gentamicin-induced stimulation of DNA synthesis in rat kidney: Comparison between in vivo and in vitro models. Toxicol. Lett. 23: 205–213.

24.

24. Richardson KA , Wilmer JL , Smith-Simpson D , and Skopek TR (1986). Assessment of the genotoxic potential of unleaded gasoline and 2,2,4-trimethylpentane in human lymphoblasts in vitro. Toxicol. Appl. Pharmacol. 82: 316–322.

25.

25. Roy AK , Neuhaus OW , and Harmison CR (1966). Preparation and characterization of a sex dependent rat urinary protein. Biochim. Biophys. Acta 127: 72–81.

26.

26. Solleveld HA , Haserman JK , and McConnell EE (1984). Natural history of body weight gain, survival, and neoplasia in the F344 rat. J. Natl. Cancer Inst. 72: 929–940.

27.

27. Universities Associated for Research and Education in Pathology, Inc. (1984). Hydrocarbon toxicity: Acute, subchronic and chronic effects in relation to unleaded gasoline exposure of rodents with comments on significance to man. Contract No. PS-6 UAREP (504–2) with American Petroleum Institute.