生物转运和生物转化.ppt

外源性化合物在体内的生物转运和生物转化
(Biotransportation and biotransformation of xenobotics)
张艳淑教授博士
公共卫生学院
Yanshu_zhang@
Tel: 3725374

Case
A pesticide,
synthesized by Zeideler, 1874; Patented Müller, 1944 (to Geigy)
Exposure way: inhalation,
digestive tract
Questions:
1 what will occur if a fast animal is administrated to DDT?
2 who is more tolerant, a chubby guy or slim one when he/she exposed to DDT for a short time?
Dichlorodiphenyl-ethanes
(DDT)
吸收
分布
代谢
排泄
生物转运
生物转化
吸收 absorption
分布 distribution
排泄 excretion
代谢 metabolism
Content
Biotransportation
Biotransformation
吸收 absorption
分布 distribution
排泄 excretion
第一节外源化学物在体内的生物转运
Section 1 Xenobiotic Biotransportation
Module 1 Cell membrane
Toxicants usually pass through a number of cells, such as
The stratified epithelium of the skin,
The thin cell layers of the lungs
The gastrointestinal (GI) tract,
Capillary endothelium,

Ultimately they enter the cells of the an.
外源化学物通过生物膜的方式
Routs of xenobiotics crossing membrane--review
简单扩散 simple diffusion
吞噬作用 phagocytosis
胞饮作用 pinocytosis
胞吐作用 exocytosis
生物转运
主动转运 active transport
被动转运passive transport
膜动转运 cytosis
易化扩散 facilitated diffusion
滤过 filtration
特殊转运special
transport
1. Passive transport
Definition :The process of xenobiotics crossing biomembrane from high concentration side to lower side
Simple diffusion
Chemicals traverse from regions of higher concentration to
regions of lower concentration .
Popular route in term of crossing membrane such as ethanol
Characters:
Non energy expenditure
Non carrier need;
No saturation condition;
petitive inhibition.
Lipid/water partition coefficients
脂水分配系数
外源性物质在脂相和水相中分配达到平衡时,其在脂相和水相中溶解度的比值。