Life-span carcinogenicity studies on Sprague-Dawley rats exposed to γ-radiation: design of the project and report on the tumor occurrence after post-natal radiation exposure (6 weeks of age) delivered in a single acute exposure

Am J Ind Med. 2015 Jan;58(1):46-60. doi: 10.1002/ajim.22391. Epub 2014 Oct 28.

Abstract

Background: Experimental long-term carcinogenicity bioassays conducted on rats and mice proved that ionizing radiation can induce a variety of tumor types. However few studies have been conducted on rats.

Methods: This report deals with the effects of γ-radiation in groups of 416-1,051 6-weeks old Sprague-Dawley rats exposed to 0, 0.1, 1, or 3 Gy of γ-radiation delivered in a single acute exposure. The experiment lasted for the animals' lifespan and all were necropsied and underwent full histopathological evaluation.

Results: The results confirm the dose-related carcinogenic effects of γ-radiation for several organs and tissues. Moreover they indicate that exposure to 0.1 Gy induces a statistically significant increased incidence in Zymbal gland carcinomas and pancreas islet cell carcinomas in females.

Conclusions: Our data show that exposure to γ-radiation induces carcinogenic effects at all tested doses.

Keywords: carcinogenicity; life-span bioassay; low-dose; rat; γ-radiation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autopsy
  • Carcinogenicity Tests
  • Disease Models, Animal
  • Dose-Response Relationship, Radiation
  • Female
  • Gamma Rays / adverse effects*
  • Male
  • Neoplasms / classification
  • Neoplasms / epidemiology*
  • Neoplasms / etiology*
  • Proportional Hazards Models
  • Radiation Dosage
  • Rats
  • Rats, Sprague-Dawley
  • Research Design