Detection And Histopathological Observation Of Phosphating Poisoning In Rats

Objerctive:Phosphatides mainly include zinc phosphatide,aluminum phosphatide,calcium phosphatide and magnesium phosphatide.They are commonly used in agriculture to protect food from rodents and insects.They are also used in the fumigation and disinfection of train cars,cabin and storage.Industrial applications include petroleum additives,flame retardants and organophosphorus chemical synthesis,and coatings for silicon crystals in semiconductor manufacturing.Phosphide in water or acid can produce colorless slightly fishy smell of highly toxic phosphine gas,death by oral inorganic phosphors or accidental absorption of phosphine occurs frequently at home and abroad.As the toxicological mechanism of phosphine poisoning has not been fully clarified,the main histopathological changes after poisoning are diverse,the typical histopathological changes are lacking,and it is not included in the scope of conventional toxicology screening,the cause of death identification of death cases caused by phosphine poisoning has always been the difficulty in forensic medicine identification.Forensic science has done little basic research on the detection and histopathological observation of phosphatide poisoning,This research through the establishment of rat acute aluminium phosphide poisoning mice model,using forensic classic phosphine silver diethyl dithiocarbamate（Ag-DDC）colorimetric method to poisoning detection of infected tissues and organs of rats,draw lessons from other subjects related to phosphine molybdenum blue colorimetric method detection principle into the contrast detection method of forensic medicine,used to explore and optimize the common phosphine detection analysis method,rich phosphine detection research of forensic medicine.At the same time,histopathological observation was carried out on the organs and tissues of poisoned rats,to study the histopathological morphological changes of organs and tissues under the mode of aluminum phosphite poisoning by gavage,to search for more typical histopathological morphological changes,and to further explore the toxicological mechanism of hydrogen phosphine poisoning.Methods:1.24 healthy and clean male SD rats were selected and provided by the animal experiment center of henan university of science and technology,with a body weight of 270±40 g.After fasting overnight,24 rats were randomly divided into the experimental group（12）and the control group（12）.In the experimental group,aluminum phosphatide 6LD₅₀（6×11.59mg/kg）was prepared by encapsulating edible oil into powder through oral gavage,and poisoning symptoms and time of death were observed and recorded.Control group was given the same amount of edible oil,the rats in the control group were recorded for 0.5 hours and sacrificed by cervical dislocation method.As experimental group and the control group rats the vital signs disappear such as breathing and heartbeat,dissecting animals quickly,take the rat blood,heart,lungs,liver,spleen,kidney,brain,stomach and gastric contents sealing bag sealing under-20℃refrigerator save waiting for inspection.In the experimental group,Ag-DDC colorimetric method and molybdenum blue colorimetric method were used for the detection of phosphine and comparative analysis.2.40 healthy and clean male SD rats with body mass（250±30）g were provided by animal experiment center of henan university of science and technology.Randomly divided into three experimental groups and a control group,each group of 10,cage feeding.Between groups rat overnight fasting before experiment,experiment,after the start of the first aluminium phosphide tablet in sealed bags knock ground into a fine powder,rats weighing according to the literature reported in rats after oral feeding aluminium phosphide LD₅₀ is 11.59mg/kg dosage calculation,the experimental group rats respectively to 5 ml cooking oil parcel of aluminium phosphide one-time pouring through the mouth of the powder into the 0.5,1.0,and 2.0 times the LD₅₀ doses,the control group rats,take 5 ml volumetric edible oil filling.The behavior of rats after experimental intervention was observed,and the time and number of death of rats in each group were recorded.The rats without death were observed for 14 days and sacrificed by the method of cervical dislocation.Lung,liver,kidney,spleen,heart,brain,testis,muscle,larynx,trachea,stomach and stomach contents were taken,fixed,rinsed,fixed,dehydrated,embedded,sectioned and stained with HE staining,and observed and photographed under light microscope.Results:1.Molybdenum blue colorimetric method can be used for quantitative detection of phosphine in biological test materials within the range of 5²5μg,the detection limit is 1.8μg,the recovery rate is 78.00±2.83⁹2.68±2.28%,the precision of the method is 1.47⁴.69%.Traditional forensic Ag-DDC colorimetry can be used for quantitative determination of phosphine in biological materials within the range of10⁴5μg,the detection limit is 10μg.2.The results of molybdenum blue colorimetric method were compared with the traditional forensic Ag-DDC colorimetric method,and it was found that there was no significant difference between the two methods in the quantitative results of blood,stomach and gastric contents（P>0.05）.Phosphine could be detected in lung,liver,spleen,kidney and brain tissues,but it could not be quantified.Phosphine was not detected in the heart.3.The mortality of rats exposed to aluminum phosphite by gavage increased with the dose（P<0.05）.The mean time of death of rats after exposure decreased with the increase of exposure dose（P<0.05）,but the decrease gradually stabilized.4.Observation results under light microscope:diffuse hemorrhage can be seen in the alveolar cavity of lung tissue in the 0.5×LD₅₀ death group,with obvious dilatation and hyperemia of the capillaries in alveolar walls and pulmonary arterioles,hyperplasia of mesenchymal epithelial cells,and obvious widening of alveolar septum;in the 1.0×LD₅₀ group,local alveolar walls of lung tissues were ruptured and fused,pulmonary small blood vessels and interstitial capillaries were congested and dilated,and alveolar septa were slightly thickened;in the 2.0×LD₅₀ group,partial alveolar wall rupture and fusion were observed in lung tissue,small pulmonary vessels and interstitial capillaries were slightly congested and dilated,and alveolar septum was slightly thickened;hepatocyte steatosis,scattered focal watery degeneration and focal necrosis,and inflammatory cell infiltration dominated by lymphocytes can be seen in local hepatic portal area;the brain tissue edema,the cerebrovascular periphery has the lymphocyte and the glial cell to gather,the exudation,wraps around the blood vessel to form the blood vessel sheath;the myocardial interstitium is loose,the myocardial cells are swollen,the cytoplasm is loose and light stained,and the structure of some myocardium is blurred;note the partial destruction or loss of glands in the gastric mucosa;spermatogenic epithelium falls off and becomes thin,spermatogenic cells are arranged in disorder.Conclusions:1.Aluminum phosphatide tablets are not stable when exposed to air,and it is easy to contact with moisture in the air to release hydrogen phosphatide gas,resulting in changes in the composition of the tablets and environmental gas pollution.This experiment adopts the aluminium phosphide tablet after sealing bag grinding into powder,and then said to take a certain amount of powder into oils on animals to fill the stomach,the method can effectively reduce the experimental process of aluminium phosphide exposed in air time,achieve the result of control variables and strengthen the laboratory safety,can provide reference for experimental animal model for the preparation of phosphine poisoning.2.Molybdenum blue colorimetric method meets the requirements for the detection of toxic substances in biological test materials.It is characterized by simple operation,rapid operation and relatively accurate qualitative and quantitative analysis.At the same time,compared with Ag-DDC pyridine method in which pyridine odor and excessive inhalation cause harm to human health,molybdenum blue colorimetric method is more safe and environmentally friendly,and the detection limit is improved.It is suitable for qualitative and quantitative detection of high content of phosphine,meeting the needs of teaching experiments and providing reference for enriching the detection technology of phosphine in forensic medicine.3.This experiment adopts the method of cooking oil parcel phosphating aluminum powder lavage successfully established acute aluminium phosphide in rats by gastric infections to histopathological observe animal model,animal infected after histopathological changes observed clearly apparent,targeted strong,safe and convenient,high feasibility,etc,can be in the future related study of oral aluminium phosphide poisoning animals experiment basis.Edible oil may have certain curative effect on early emetic treatment of oral aluminum phosphite poisoning,which can isolate gastric acid and slow down the release time of hydrogen phosphine when aluminum phosphite meets gastric acid.4.Acute aluminum phosphide lavage of rats infected rats can cause lung,liver,brain,heart,stomach,testicular multiple organ tissue pathology change,especially the damage to the lungs change obviously,pulmonary hemorrhage,alveolar wall thickening（capillary hyperemia,hyperplasia of epithelial cells of the stroma）,local alveolar walls fracture and integration as the main pathological changes,and show the high dose group infected with pulmonary congestion,alveolar walls slightly thickened,local alveolar walls fracture and integration as the main lung performance,low dose group infected pulmonary hemorrhage,alveolar wall thickening,as the main lung performance,canister to death each rat pulmonary congestion,hemorrhage,alveolar wall thickening phenomenon and infected showed a negative correlation between dose,The longer the survival time was,the more obvious the pathological changes were.5.This experiment on alveolar wall thickening phenomenon（stromal hyperplasia of epithelial cells）in a certain extent,reveals the part of phosphine poisoning mechanism of pulmonary interstitial epithelial hyperplasia is adaptability,universality,toxic damage in lung tissue repair of nonspecific reaction,is a kind of oxidation stress under the action of lung to the defence of the poison damage,legacy alive after infected rats with irreversible damage,alveolar walls are thickened and pulmonary congestion,hemorrhage phenomenon disappears.It has been proved that hydrogen phosphine can exert toxic damage through oxidative stress mechanism and produce irreversible lung mesenchymal epithelial cell proliferation injury.