肺脾两虚型COPD模型大鼠下丘脑、胃组织Ghrelin及其受体的表达变化

目的:观察肺脾两虚型慢性阻塞性肺疾病(COPD)模型大鼠下丘脑组织、胃组织中生长激素释放肽(Ghrelin)及其受体GHS-R的变化,结合脑肠轴调节作用探究其在COPD肺脾两虚型大鼠模型中的作用。方法:48只Wistar大鼠随机分为空白组、肺脾两虚型COPD观察组(根据造模时间不同,分为28,35,42 d组),每组12只。空白组大鼠吸入空气+气管内注射等量生理盐水+灌服等量生理盐水;观察组烟熏+气管内滴注脂多糖(造模第1,14天)+灌服冰冷番泻叶浸液至造模结束。于造模28,35,42 d末将大鼠处死,取大鼠胃组织及下丘脑组织,分别采用蛋白免疫印迹法(Western blot),免疫组化法及实时荧光定量PCR法(Real-time PCR)检测大鼠各组织中脑肠肽Ghrelin及其受体GHS-R的蛋白含量及mRNA水平,观察其在疾病过程中的动态表达。结果:与空白组比较,模型组大鼠随着造模时间的增长,其下丘脑、胃组织中Ghrelin及其受体GHS-R的蛋白表达逐渐减少(P0.05);同时,模型组各组大鼠下丘脑、胃组织Ghrelin及GHS-R的平均吸光度呈不同程度减少(P0.05);另外,模型组大鼠下丘脑组织、胃组织的mRNA表达水平也不同程度降低(P0.05)。结论:Ghrelin及其受体在下丘脑组织、胃组织中的表达变化或许是引起COPD合并营养不良的原因之一,脑肠轴的调节作用在COPD营养状况不良状况中起着重要作用。

Expressions of Ghrelin and Its Receptors in Hypothalamus and Gastrointestinal Tract of Lung and Spleen Deficiency-type Chronic Obstructive Pulmonary Disease Model Rats

Objective: To observe the changes in Ghrelin and GHS-R in hypothalamus, gastric tissue of model rats with lung and spleen deficiency-type chronic obstructive pulmonary disease (COPD), and study the regulatory effect of the brain and intestine axis to explore its role in the rat model of COPD. Method: Totally 48 Wistar rats were randomly divided into blank control group, lung and spleen deficiency-type COPD observation group (28, 35, 42 d according to different modeling time). The rats in the control group were provided with air, intratracheally injected with the same amount of normal saline, and orally administered with the same amount of normal saline. The rats in the observation group were smoked and intratracheally instilled with lipopolysaccharide (on the 1^st day, the 14^th day) and gavaged with diarrhea leaves to the end of modeling. Rats were put to death at the 28^th, 35^th and 42^th days after modeling, and their gastric tissues and hypothalamus were collected. Western blot, immunohistochemistry and Real-time PCR were used to detect protein and mRNA expressions of Ghrelin and GHS-R in rat tissues, and the dynamic expressions of Ghrelin and GHS-R were observed. Result: Compared with the blank control group, the expressions of Ghrelin and GHS-R in the hypothalamus and gastric tissue of the model group decreased gradually (P<0.05), with statistically significant differences (P<0.05). The mean optical densities of Ghrelin and GHS-R in hypothalamus and gastric tissues of the model group were significantly decreased (P<0.05), with statistically significant differences. In the model group, mRNA expressions of hypothalamus and gastric tissues were also decreased (P<0.05), with statistically significant differences. Conclusion: The expressions of Ghrelin and its receptors in hypothalamus and gastric tissues may be one of the causes of COPD complicated with malnutrition. The regulatory effect of brain stem axis plays an important role in the poor nutritional status of COPD.