Effects of 2, 4, 5-trichlorophenoxyacetic acid, pentachlorophenol, methylprednisolone, and freund’s adjuvant on 2-hydroxyethylnitrosourea carcinogenesis in mrc-wistar rats

A link was proposed between human non-Hodgkin’s lymphoma and exposure to 2, 4, 5-trichlorophenoxyacetic acid (245T) and pentachlorophenol (PCP). To test this view and the hypothesis that immune suppression or stimulation could affect B-cell lymphoma (BCL) induction, we administered chronically to MRC-Wistar (MRC-W) rats of both sexes 98% pure 245T (600 mg/kg diet), 86% pure PCP (500 mg/kg diet), methyl- prednisolone (20 mg/kg ip weekly), and Freund’s adjuvant (0.5 ml im every 3-6 wk) for 40 wk, together with 75 mg 2-hydroxyethylnitrosourea (HENU)/I drinking water, a system known to induce B-cell lymphoma.