内毒素对心肌脂质代谢的影响

目的：研究内毒素对心肌脂质代谢的影响,并探讨其可能的作用机理。方法：雄性大白鼠共69只,随机分为10组。分别用游离脂肪酸和甘油三酯两类脂质,以在体和体外两种方式应用内毒素,利用离体工作心脏模型,观察心肌脂质代谢的变化。结果：体内注入大剂量内毒素鼠,游离脂肪酸灌注心脏的脂肪酸氧化率减少30％;内毒素体外直接用于离体灌注心脏,心肌LPL活性均增高,甘油三脂氧化利用增多。内毒素还使心肌各类脂质沉积增加。结论：内毒素对心肌脂质代谢有明显影响,其机理因脂质类型不同而表现为间接或直接作用。     

α-MSH拮抗剂对内毒素及肿瘤坏死因子性发热的作用

目的：观察α－黑素细胞刺激素（α－ＭＳＨ）拮抗剂［Ｄ－Ｔｒｐ７,Ａｌａ８,Ｄ－Ｐｈｅ１０］α－ＭＳＨ（６－１１）－ａｍｉｄｅ对家兔内毒素（ＥＴ）及肿瘤坏死因子（ＴＮＦ）性发热的影响。方法：侧脑室给药,ＳＴ－１型数字温度计测家兔的结肠温度。结果：（１）静脉注射ＥＴ,家兔体温呈典型的双相热;若事先侧脑室注射α－ＭＳＨ拮抗剂,则体温升高更明显,且热程明显延长,６ｈ体温反应指数（ＴＲＩ６）显著高于ＮＳ＋ＥＴ组（Ｐ＜０．０１）。（２）侧脑室注射ＴＮＦ－α引起体温明显升高;事先给予α－ＭＳＨ拮抗剂,则显著增强ＴＮＦ－α性发热效应（Ｐ＜０．０１）。而α－ＭＳＨ拮抗剂对正常体温无影响。结论：内源性解热物质α－ＭＳＨ在限制发热中发挥了重要作用。     

Difference between periportal and pericentral Kupffer cells in lipopolysaccharide uptake in rats

AIM: To reveal the difference in the ability of Kupffer cells in the periportal and pericentral regions of the liver to uptake lipopolysaccharides (LPS) injected into the portal vein.METHODS: Male Wistar rats were divided into two groups: normal control group (n = 6) and GdCl₃-treated group (n = 8). Sixteen hours before the experiment, rats in the GdCl₃-treated group were injected with GdCl₃ via the tail vein to eliminate Kupffer cell function specifically in the periportal region. LPS at a dose of 20 μg/100 g body weight was injected into rats of both groups via the portal vein. Zero, 2, 5, 10, 30, and 60 min after LPS injection, liver samples were obtained and the distribution of LPS in Kupffer cells was observed by immunofluorescence imaging of monoclonal antibody-specific LPS staining using a confocal laser scanning microscope.RESULTS: In the normal control group, positive reactions to LPS were found in Kupffer cells in the periportal region with the peak at two minutes after LPS injection. Kupffer cells in the pericentral region showed the peak at five minutes after LPS injection, but its fluorescent intensity to LPS at the peak time in the cytoplasm was significantly lower than that of Kupffer cells in the pericentral region. In the GdCl₃-treated group, Kupffer cells in the pericentral region showed the peak at two minutes following LPS injection, and the LPS fluorescent intensity showed no significant difference from that of the normal control rats at the peak point. No significant changes of LPS fluorescent intensities were found in Kupffer cells in the periportal region at various time points following LPS injection in GdCl₃-treated rats.CONCLUSION: Kupffer cells in the periportal and pericentral regions showed differences in LPS uptake via the portal vein.     

热原检查中家兔注射细菌内毒素后的升温情况考察

目的:考察细菌内毒素剂量与热原检查家兔法家兔体温的关系。方法:选择未进行任何实验的家兔,每1 kg家兔体质量分别静脉注射细菌内毒素0.25、0.5、1.0、2.0、2.5、5.0、10.0 EU,观察家兔注射细菌内毒素后的升温情况。结果:细菌内毒素注射剂量在0.5 EU/kg之下时,家兔的体温稳定,在0.5 EU/kg以上的细菌内毒素注射剂量时,家兔呈现不同温差的升温度数,注射剂量超过2 EU/kg时,每组有至少一只家兔升温超过0.6℃。结论:热原检查家兔法内毒素剂量>5 EU/kg,家兔总体均有明显升温;内毒素注射剂量与家兔升温度数存在剂量关系。