Principles of Toxicology Yuan, Zhanpeng, Ph.D. Tel. ： 6875 9982; 139 8612 0848 E-mail: zpyuan@whu.edu.cn.

Principles of ToxicologyYuan, Zhanpeng, Ph.D.

Tel.6875 9982; 139 8612 0848E-mail: zpyuan@whu.edu.cn

Essentials of Toxicology

Touch up

Review

Further ClarifyObjectives

ContentsGeneral Principles of Toxicology

Absorption-Distribution-Excretion

General Classification of Toxicants

Specific Discussion of Toxicants

ToxicologyToxicology is the study of poisons

Poisons are chemical/physical agents that produce adverse responses in biological organisms

General Principles of ToxicologyADME

Classifications of Toxicity

Mechanisms of Toxicity

Primary Determinants of Toxicity

Toxicity Modifiers

ETC.

ADMEToxicological Process

Transport Process Mechanisms

Toxicokenetics

Toxicokenetics and PBPK modeling

Absorption-Distribution-ExcretionToxicological Process

Toxicokinetics

Classification of ToxicityAcute toxicity: adverse effect resulting from a single, usually large, exposure to a toxinSubacute toxicity: Somewhat acute, between acute and chronic (online med. dictionary)Chronic toxicity: harmful effect from repeated exposures to a toxin for 3+ monthsTherapeutic indexLD50/ED50Risk: probability that injury will result from exposure to a substance for given conditions, dose, and route

MechanismsAlterations in receptor-ligand interactionsNicotine, most drugsAlterations in membrane functionLocal anesthetics, hydrocarbonsInterference with cellular energy mechanismsCyanide, PentachlorophenolCovalent binding to biomoleculesOrganophosphates, alkylating agentsCausing non-lethal alterations in somatic cellsCarcinogens, e.g. aflatoxinAlterations in ligand-activated transcription factors, e.g. DioxinsBy inducing programmed cell death (apoptosis), e.g. Acetaminophen

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