Drug Interactions; Environment; Microsomes/enzymology; Pharmaceutical Preparations/metabolism; Animals; Antipyrine/metabolism; Barbiturates/pharmacology; Bilirubin/metabolism; Carcinogens/metabolism; Environmental Pollution; Estrogens/metabolism; Female; Humans; Hydrocarbons/metabolism; Hydrocarbons/pharmacology; Male; Methyltransferases/metabolism; Mixed Function Oxygenases/metabolism; Oxidoreductases/metabolism; Pesticides/metabolism; Pesticides/pharmacology; Plants, Toxic; Pregnancy; Rats; Reproduction/drug effects; Steroids/metabolism; Nicotiana; Vitamins/metabolism