Malignant transformation of rat kidney induced by environmental substances and estrogen

Int J Environ Res Public Health. 2012 May;9(5):1630-48. doi: 10.3390/ijerph9051630. Epub 2012 May 4.


The use of organophosphorous insecticides in agricultural environments and in urban settings has increased significantly. The aim of the present study was to analyze morphological alterations induced by malathion and 17β-estradiol (estrogen) in rat kidney tissues. There were four groups of animals: control, malathion, estrogen and combination of both substances. The animals were injected for five days and sacrificed 30, 124 and 240 days after treatments. Kidney tissues were analyzed for histomorphological and immunocytochemical alterations. Morphometric analysis indicated that malathion plus estrogen-treated animals showed a significantly (p < 0.05) higher grade of glomerular hypertrophy, signs of tubular damage, atypical proliferation in cortical and hilium zone than malathion or estrogen alone-treated and control animals after 240 days. Results indicated that MFG, ER-α, ER-β, PgR, CYP1A1, Neu/ErbB2, PCNA, vimentin and Thrombospondin 1 (THB) protein expression was increased in convoluted tubules of animals treated with combination of malathion and estrogen after 240 days of 5 day treatment. Malignant proliferation was observed in the hilium zone. In summary, the combination of malathion and estrogen induced pathological lesions in glomeruli, convoluted tubules, atypical cell proliferation and malignant proliferation in hilium zone and immunocytochemical alterations in comparison to control animals or animals treated with either substance alone. It can be concluded that an increased risk of kidney malignant transformation can be induced by exposure to environmental and endogenous substances.

Keywords: CYP1A1; ER-α; ER-β; MFG; Neu/ErbB2; PCNA; PgR; THBS; atypical cell proliferation; estrogen; kidney; malathion; vimentin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinogens / toxicity*
  • Cytochrome P-450 CYP1A1 / metabolism
  • Drug Synergism
  • Estradiol / toxicity*
  • Estrogen Receptor alpha / metabolism
  • Estrogen Receptor beta / metabolism
  • Estrogens / toxicity*
  • Female
  • Insecticides / toxicity*
  • Kidney Neoplasms / chemically induced*
  • Kidney Neoplasms / metabolism
  • Kidney Neoplasms / pathology
  • Malathion / toxicity*
  • Proliferating Cell Nuclear Antigen / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, ErbB-2 / metabolism
  • Receptors, Progesterone / metabolism
  • Thrombospondin 1 / metabolism
  • Vimentin / metabolism


  • Carcinogens
  • Estrogen Receptor alpha
  • Estrogen Receptor beta
  • Estrogens
  • Insecticides
  • Proliferating Cell Nuclear Antigen
  • Receptors, Progesterone
  • Thrombospondin 1
  • Vimentin
  • Estradiol
  • Cytochrome P-450 CYP1A1
  • Erbb2 protein, rat
  • Receptor, ErbB-2
  • Malathion