硒营养状况对大鼠感染肺炎支原体发病率的影响

本研究以大鼠为动物模型，观察了缺硒或适硒大鼠感染肺炎支原体（ＭＰ）间质性肺炎的发病率，以及感染后灌喂亚硒酸钠对发病率的影响。选择３周龄断乳Ｗｉｓｔａｒ大鼠１５０只，在喂饲各自实验饲料４周后，用乙醚麻醉Ｂ、Ｃ、Ｄ、Ｅ组动物，滴鼻感染肺炎支原体（ＭＰ）菌液，Ｃ组在感染的同时，开始灌喂亚硒酸钠溶液（２Ｓｅμｇ／ｍｌ，每天灌喂剂量为１．５～２ｍｌ），持续１８天；Ｄ组在感染后第１１天灌喂亚硒酸钠溶液，持续７天；Ｂ组和Ｅ组自感染之日起，灌喂生理盐水１８天，Ａ组无感染。结果证明，适硒感染组支原体肺炎发病率低，适硒感染组和低硒感染同时补硒组严重肺炎例数和心肌损害例数均少于缺硒感染组。提示良好的硒营养状况可减少大鼠ＭＰ肺炎发病率，对感染时的心肌有保护作用；补硒可减轻病情和加速病变恢复

Effect of Selenium Status on the Morbidity of Interstitial Pneumonia in Rats Infected with Mycoplasma

To investigate the effect of selenium(Se) status on morbidity and process of interstitial pneumonia, we used the Wistar rats as the animal model infected with Mycoplasma Pneumonia (MP). The rats were maintained on the based diets with different doses of Se, infected with MP and exposed to sodium selenite(1.5-2.0 ml/day, containing Se 2 micrograms/ml) or 0.9% NaCl (1.5-2.0 ml/d) by gavage for different time. The experimental rats were divided into five groups, group A, feeding with normal control diet and without infected MP, group B with adequate Se diet and infected MP, group C with Se deficiency diet infected MP and added Se at the same time, group D with Se deficiency diet and added Se after suffered with MP, and group E with Se deficiency diet and infected MP. The results showed that the MP morbidity of the rats fed with high Se diet was significantly lower than that of the rats fed with low Se diet. The pathological change was significant in the low Se group and relatively mild in the high Se group. After infected with MP, the supplementation of sodium selenite to the low Se rats might decrease the MP morbidity and shorten the disease course compared with the group without supplementing Se. The incidence of myocarditis in the infected group with normal Se level diet or in the infected group with Se supplement was lower than that in the group without Se supplementation. The concentrations of Se in plasma and glutathione peroxidase in plasma and white blood cells decreased to a certain level after infection. The present study indicated a positive influence of Se supplement on the morbidity, disease course, and state of interstitial pneumonia in rats.