Department of Nutrition and Dietetics, Erzincan University, Erzincan, Turkey.
Mol Cell Biochem. 2011 Sep;355(1-2):299-308. doi: 10.1007/s11010-011-0867-5. Epub 2011 May 10.
The aims of the present study were to examine ghrelin expression in serum and gastrointestinal tract (GIT) tissues, and to measure tissue ghrelin levels and obesity-related alterations in some serum biochemical variables in rats with diet-induced obesity (DIO). The study included 12 male rats, 60 days old. The rats were randomly allocated to two groups (n = 6). Rats in the DIO group were fed a cafeteria-style diet to induce obesity, while those in the control group were fed on standard rat pellets. After a 12 week diet program including an adaptation period all rats were decapitated, tissues were individually fixed, ghrelin expression was examined by immunohistochemistry , and tissue and serum ghrelin levels were measured by radioimmunoassay. Serum biochemical variables were measured using an autoanalyzer. When the baseline and week 12 body mass index and GIT ghrelin expression were compared between DIO and control rats, BMI had increased and ghrelin expression decreased due to obesity. The RIA results were consistent with these findings. Serum glucose, LDL cholesterol, and total cholesterol levels were elevated and HDL cholesterol significantly decreased in the DIO group. A comparison of GIT tissues between the control and obese groups demonstrated that ghrelin was decreased in all tissues of the latter. This decrease was brought about a decline in the circulating ghrelin pool. This suggests that rather than being associated with a change in a single tissue, obesity is a pathological condition in which ghrelin expression is changed in all tissues.
本研究旨在探讨肥胖大鼠血清和胃肠道（GIT）组织中 ghrelin 的表达，并测量组织 ghrelin 水平以及与肥胖相关的一些血清生化变量的变化。研究纳入了 12 只 60 天大的雄性大鼠。将大鼠随机分为两组（n = 6）。DIO 组给予 cafeteria 饮食以诱导肥胖，对照组给予标准大鼠颗粒饲料。经过 12 周的饮食计划（包括适应期），所有大鼠断头，单独固定组织，通过免疫组织化学检测 ghrelin 的表达，并通过放射免疫法测量组织和血清 ghrelin 水平。使用自动分析仪测量血清生化变量。当比较 DIO 组和对照组大鼠的基线和第 12 周体重指数和 GIT ghrelin 表达时，由于肥胖，BMI 增加，ghrelin 表达减少。RIA 结果与这些发现一致。DIO 组血清葡萄糖、LDL 胆固醇和总胆固醇水平升高，HDL 胆固醇显著降低。对照组和肥胖组 GIT 组织的比较表明，ghrelin 在后者的所有组织中均减少。这种减少是由于循环 ghrelin 池的减少所致。这表明肥胖不是与单个组织的变化相关，而是一种 ghrelin 表达在所有组织中都发生变化的病理状态。
