Repeated administration of carcinogen in critical developmental periods increases susceptibility of female Wistar: han rats to mammary carcinogenesis induction.

Analysis and knowledge of individual strain susceptibility of experimental animals to induction of carcinogenesis is important especially in regard to possibility of transfer of these facts to human pathology, first of all to chemopreventive projects. Our group (AHLERS et al. [1]) reported very low sensitivity of female Wistar:Han rats to induction of mammary carcinogenesis by 7,12-dimethylbenz(a)anthracene (DMBA) and by N-methyl-N-nitrosourea (NMU).

Mammary carcinogenesis induced in Wistar:han rats by the combination of ionizing radiation and dimethylbenz(a)anthracene: prevention with melatonin.

The primary cancer chemoprevention is an important topic of experimental oncology. We have analyzed the possible oncostatic properties ofmelatonin in a combined model of radiation plus chemocarcinogen-induced mammary carcinogenesis. Virgin female rats of Wistar:Han strain were continuously irradiated with daily dose 96 mGy of gamma rays up to 15 days.

Effects of retinyl acetate and melatonin on N-methyl-N-nitrosourea-induced mammary carcinogenesis in rats. A preliminary report.

The aim of this project was to evaluate the effect of retinyl acetate (RA), melatonin (Mel) and their combination on N-methyl-N-nitrosourea (NMU)-induced rat mammary carcinogenesis. Female Sprague-Dawley rats were given two intraperitoneal doses of NMU, each of 50 mg/kg of b.w.