内科学 有机磷农药中毒-吕玲 (英文)【荐】.pptVIP

Specific Properties Basic chemical structures R1－O R2－O Physical and chemical property A oil or crystalline substance, that is yellow to brown possessing an unpleasant smell. Insoluble in water; soluble in organic liquid. Easily dissolved in alkalizing condition. Degree of toxicity Many of them are highly or extremely toxic . Exposure situations Occupational Enviromental Absorb and Metabolism Absorb - May be absorbed through respiratory or digestive tract - Also through skin. Metabolism - Mainly in the liver - by oxidation, detoxication processes Mechanism of toxic action The AChE (acetylcholinesterase of cholinesterase) is inhibited. Organophorus combines the AChE, resulting organophosphate-cholinesterase. causing acumilation of acetylcholine. Clinical manifestations Acute poisoning - Muscarinic sign: presented with constraction, excessive lacrimal secretion - Nicotinic sign：Excessive accumulation of -Central nervous system signs AChE in neuromuscular transmission Degree of poisoning - Mild poisoning： M sign - Moderate poisoning ：N sign, muscular fibrillation - Heavy poisoning ： coma、pulmonary edema breath paralysis、brain edema Organophosphate Induced Delayed Polyneuropathy (OPIDP) 2～3 weeks（4～45 days）after disappearance of acute symptoms . It is not related to the inhibition of ChE，but is related to inhibition of neuropathy targeted NTE. - Progressive stage: - Stable stage：3-12 months. - Remission stage：6-18 months. Intermediate syndrome 24～96 hours after acute poisoning，muscle paralysis . It is related to long inhibition of ChE（delay elimination of pesticides, not due to enough drug, soluble