title: Multiple forms of inducible drug-metabolizing enzymes: a reasonable mechanism by which any organism can cope with adversity.
abstract: All organisms possess a number of genetically regulated mechanisms in order to cope with rapid adverse changes in the environment. The two systems which appear to respond to a seemingly endless array of chemical specificities are the immune response and the induction of drug-metabolizing enzymes. Similarities and differences between the immunoglobulin and the cytochrome P-450-mediated monooxygenase systems are described. DNA insertion sequences, plasmid "transposons," maize "controlling elements," gene duplication, intervening sequences, and high-frequency intergenic recombination are all discussed as possible methods by which organisms can "adapt" quickly to a new selective pressure. If the regulation of P-450 induction resembles in any way the other methods by which pro- and eukaryotes cope genetically with numerous forms of environmental adversity, therefore, it is very likely that mammalian tissues contain hundreds, if not thousands, of inducible forms of P-450.
mesh_terms: D000222:Adaptation, Physiological; D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D000818:Animals; D000917:Antibody Formation; D000937:Antigen-Antibody Reactions; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000276:immunology / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000235:genetics; D004790:Enzyme Induction; D005784:Gene Amplification; D005809:Genes, Regulator; D005815:Genetic Code; D007136:Immunoglobulins / Q000235:genetics; D008214:Lymphocytes / Q000276:immunology; D009154:Mutation; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D010957:Plasmids / Q000187:drug effects; D011995:Recombination, Genetic / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D007136:Immunoglobulins; D004364:Pharmaceutical Preparations; D003577:Cytochrome P-450 Enzyme System; D000445:Aldehyde Oxidoreductases; D003576:Electron Transport Complex IV