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離子:與蛋白結(jié)合,如金屬硫蛋白,儲存于肝腎中。 脂溶性較強(qiáng)的物質(zhì):儲存于體脂內(nèi)。 環(huán)境污染物在體內(nèi)的分布與貯存 Accumulation: ? Material accumulation( 物質(zhì)蓄積):物質(zhì)的積累 ? Functional accumulation( 功能蓄積):功能的改變 環(huán)境污染物在體內(nèi)的轉(zhuǎn)化 生物轉(zhuǎn)化( Biotransformation): 第一階段反應(yīng)( I相反應(yīng)或降解反應(yīng)) (phase I biotransformation, or degradation reaction) 第二階段反應(yīng)( II相反應(yīng)或結(jié)合反應(yīng)) (Phase II biotransformation, or conjugation reaction) 環(huán)境污染物在體內(nèi)的轉(zhuǎn)化 生物轉(zhuǎn)化( Biotransformation): Phase I biotransformation, or degradation reaction Introduction of a polar group into the pound. a. Oxidation b. Reduction c. Hydrolysis 環(huán)境污染物在體內(nèi)的轉(zhuǎn)化 生物轉(zhuǎn)化( Biotransformation): Phase II biotransformation, or conjugation reaction In phase II reactions, substances are bined with endogenous hydrophilic pounds. The result is a substance with sufficient hydrophilic character to allow rapid excretion. 環(huán)境污染物在體內(nèi)的轉(zhuǎn)化 生物轉(zhuǎn)化的結(jié)局 : 生物解毒作用: ( Detoxication) 生物活化作用: ( Bioactivation) 生物活化作用: ( Bioactivation) 環(huán)境污染物在體內(nèi)的轉(zhuǎn)化 生物轉(zhuǎn)化的結(jié)局 : 環(huán)境污染物在體內(nèi)的排泄: ? Urinary excretion ? Fecal excretion ? Sweat, milk, saliva, hair and nails. ? Exhalation 環(huán)境污染物在體內(nèi)的排泄: Most pounds eliminated by kidneys polar and ionic pounds At what urine pH are bases absorbed? excreted? 環(huán)境污染物在體內(nèi)的排泄: 腸肝循環(huán) (Enterohepatic circulation) duodenum Common bile duct Polar bacterial hydrolysis nonpolar Xenobiotics Accumulation Accumulation in body fat PhaseI (bioactivation or inactivation) Oxidation, reduction, hydrolysis Phase II (bioinactivation) conjugation Extracellular mobilization Highly lipophilic Metabolically stable lipophilic polar hydrophilic polar hydrophilic Biliary excretion plasma circulation renal excretion 衡量環(huán)境污染物毒性的常用指標(biāo) Toxicity: 化學(xué)物引起機(jī)體損害的能力。 Toxicant: 存在于自然環(huán)境中,進(jìn)入人體后能引起機(jī)體病理性損害的化學(xué)物質(zhì)即為毒物。 Environmental