The influence of feeding a pharmacological level of either selenium (SE), retinyl acetate (RA), or selenium and retinyl acetate (SE + RA) on N-methyl-N-nitrosourea-induced mammary carcinogenesis was studied in female Sprague Dawley rats. Rats received 50 mg N-methyl-N-nitrosourea per kg body weight at 50 days of age. Seven days after carcinogen treatment, groups of 25 rats each were placed on l...
