| With the rapid development of China’s feed industry,China has become the world’s largest feed producer in 2013.Feed quality is closely related to animal husbandry,including livestock and poultry health and animal product safety.Lead is one of the main pollutants.Lead-containing ‘industrial waste’ emissions pollute the environment and feed ingredients.After being fed by animals,they enter the bio-chain and accumulate in the body,damaging multiple tissues and organs.Selenium is an essential trace element in the body.It has anti-aging,enhances immunity,anti-oxidation and anti-tumor effects.It has detoxification effect on heavy metals and is known as the ‘natural antidote to heavy metals.’ In order to assess the contamination of feed Pb in Heilongjiang Province,feed samples from various parts of Heilongjiang Province from 2014 to 2016 were tested for Pb content by atomic absorption spectroscopy.At the same time,in order to investigate the toxic effects of Pb contamination on chicken spleen cells and the antagonistic effects of Se on Pb toxicity,the model of Se antagonism against Pb was replicated and used to detect the microscopic structure in the spleen tissue of the chicken,the content of Pb and Se,the level of oxidative stress,and the m RNA and protein levels of the procedural necrosis associated pathways and heat shock proteins(HSP s).At the same time,in vitro experiments were carried out to verify the mechanism of Se antagonism against Pb-induced cytotoxicity in chicken spleens.The results are shown as follows:(1)Between 2014 and 2016,in feed samples from various parts of Heilongjiang Province,there were 214 broiler feeds,and the excess rate of Pb content was 18.22%;Egg feed was 226 and the excess rate of Pb content was 0.00%.(2)Compared with the normal group,there was no significant difference in all parameters detected in spleen tissues and cells of Se group(p > 0.05);the results of Pb and Se contents,and oxidative stress levels in the Pb group were significantly different(p < 0.05).The changes in Pb and Se contents,oxidative stress level,NF-κB inflammatory pathway and MAPK pathway were between the control group and Pb group,and statistically showed significant differences.These results indicated that Pb is toxic to spleen cells in chickens,and Se can alleviate the toxicity of lead.(3)The results of AO/EB double fluorescence staining and flow cytometry showed that Pb can induce procedural necrosis of chicken spleen cells,and the addition of Se can alleviate the necrosis rate of lymphocytes to some extent.(4)The results of procedural necroso-related pathways showed a significant increase in the m RNA and protein levels of MLKL,RIP 1,RIP 3,and FADD in the Se-Pb group(p < 0.05),and the increase in the m RNA and protein levels in the Pb group was the largest;the m RNA and protein levels of Caspase-8 in the Se-Pb group decreased significantly(p < 0.05),and the level of m RNA and protein in the Pb group reached the lowest.It was further proved that the Pb-induced procedural necrosis of chicken spleen cells could be significantly improved by adding Se in feed.(5)By detecting the m RNA and protein levels of heat shock protein-related genes(HSP 27,HSP 40,HSP 60,HSP 70 and HSP 90),it was found that lead can induce the increase of heat shock protein-related genes at m RNA and protein levels.Adding selenium can alleviate heat shock.Increases in protein and protein levels of protein-related genes suggest that lead can induce stress in spleen tissues and cells by activating the heat shock protein family.The addition of selenium alleviated the stress induced by lead in chicken spleen tissues and cells by inhibiting the activation of the heat shock protein family to some extent.In summary,there was excessive lead content in Heilongjiang province broiler feed;the excess Pb in the feed has a toxic effect on the spleen of the chicken,manifested in pathological changes,inflammatory reactions,and procedural necrosis of the spleen.The addition of Se can alleviate histopathological changes,inflammatory reactions,and procedural necrosis to some extent.It indicated that Se can be used as an effective antidote for Pb in animal production. |
