title: Role of age in host sensitivity to carcinogens.
abstract: The possible mechanisms of age-associated changes in host sensitivity to carcinogenic agents are discussed. It has been suggested that the main modifying factors of carcinogenesis in aged organisms are age-associated shifts in: (1) activity of carcinogen-metabolizing enzymes in liver and other target tissues; (2) binding of active carcinogen metabolites to macromolecules (nucleic acids and proteins); (3) accuracy of DNA repair; and (4) proliferative activity of target tissue, regulated by tissue-specific factors (chalones and growth factors), hormones and some metabolic factors (cholesterol, fatty acids). A scheme of carcinogenesis is presented which integrates the effects of carcinogens at subcellular, tissue and organism levels.
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000494:pharmacology; D000375:Aging; D000818:Animals; D002273:Carcinogens / Q000378:metabolism / Q000633:toxicity*; D003110:Colonic Neoplasms / Q000139:chemically induced; D004260:DNA Repair / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008770:Methylnitrosourea / Q000633:toxicity; D009369:Neoplasms / Q000139:chemically induced* / Q000453:epidemiology; D014594:Uterine Neoplasms / Q000139:chemically induced; D014625:Vaginal Neoplasms / Q000139:chemically induced
chemical_list: D002273:Carcinogens; D015127:9,10-Dimethyl-1,2-benzanthracene; D008770:Methylnitrosourea