Wang Suxing, Li Fang, Wang Na, Lyu Caixia, Shao Weihua, Li Xiuqin, Li Shaobing
The Second Department of Geriatrics, Hebei General Hospital, Shijiazhuang 050051, China.
Wei Sheng Yan Jiu. 2020 Jul;49(4):580-584. doi: 10.19813/j.cnki.weishengyanjiu.2020.04.010.
To observe the changes of neuropeptide Y(NPY) expression in perirenal adipose tissue and its relationship with insulin resistance in the nutritional transition models of refeeding after calorie restriction.
SPF Male SD rats, aged 8 weeks, were randomly divided into normal chow group and refeeding with normal chow after calorie restriction for 4 weeks group. NPY gene expression in perirenal adipose tissue were detected by real-time quantitative PCR at the end of 4 and 12 weeks, along with fasting plasma glucose, fasting serum lisulin, free fatty acids and average glucose infusion rate(GIR_(60-120)) of hyperinsulinemic-euglycemic clamp test for 60-120 minutes. NPY gene mRNA expression in perirenal adipose tissue was detected by real-time quantitative PCR. And the relationship between NPY gene expression and insulin resistance was detected by Spearman correlation analysis.
The expression level of NPY gene in perirenal adipose tissue in caloric restriction for 4 weeks group was significantly increased by calorie restriction(P<0. 01). After refeeding, the expression level of NPY gene in refeeding with normal group was still slightly increased, which was significantly higher than that in normal group at the end of the experiment(P<0. 01). The levels of fasting plasma glucose and fasting insulin in caloric restriction for 4 weeks group decreased slightly, GIR_(60-120) increased slightly, but there were no statistical differences compared with normal group(P>0. 05), but free fatty acid levels increased significantly(P<0. 01). After refeeding, the levels of fasting insulin, free fatty acid in refeeding with normal group increased significantly, GIR_(60-120) decreased evidently(P<0. 01), but the changes of fasting blood glucose were not obvious. The result of stepwise regression showed that the expression level of NPY gene in perirenal adipose tissue was closely related to GIR_(60-120) and fasting insulin, with R values of-0. 816 and 0. 789 respectively(R~2=0. 892, P<0. 01). The result of correlation analysis showed that in the 4-week group, the mRNA expression level of NPY gene in perirenal adipose tissue was closely related to GIR_( 60-120)、fasting insulin and free fatty acid, with R values of-0. 765, 0. 716 and 0. 657 respectively(P<0. 01). In the 12 week group, the mRNA expression level of NPY gene in perirenal adipose tissue was closely related to GIR_(60-120), fasting insulin and free fatty acid, with R values of-0. 853, 0. 622 and 0. 608 respectively(P<0. 01).
The mRNA expression of NPY gene in perirenal adipose tissue was closely related to indicators of insulin resistance. It is an important factor affecting insulin sensitivity.
观察热量限制后再喂养营养过渡模型中肾周脂肪组织神经肽Y（NPY）表达的变化及其与胰岛素抵抗的关系。
将8周龄SPF级雄性SD大鼠随机分为正常饮食组和热量限制4周后再喂养正常饮食组。于4周和12周结束时，采用实时定量PCR检测肾周脂肪组织中NPY基因表达，同时检测空腹血糖、空腹血清胰岛素、游离脂肪酸以及60 - 120分钟高胰岛素 - 正常血糖钳夹试验的平均葡萄糖输注率（GIR60 - 120）。采用实时定量PCR检测肾周脂肪组织中NPY基因mRNA表达。通过Spearman相关分析检测NPY基因表达与胰岛素抵抗的关系。
热量限制4周组肾周脂肪组织中NPY基因表达水平因热量限制显著升高（P<0.01）。再喂养后，正常再喂养组NPY基因表达水平仍略有升高，实验结束时显著高于正常组（P<0.01）。热量限制4周组空腹血糖和空腹胰岛素水平略有下降，GIR60 - 120略有升高，但与正常组相比无统计学差异（P>0.05），但游离脂肪酸水平显著升高（P<0.01）。再喂养后，正常再喂养组空腹胰岛素、游离脂肪酸水平显著升高，GIR60 - 120明显降低（P<0.01），但空腹血糖变化不明显。逐步回归结果显示，肾周脂肪组织中NPY基因表达水平与GIR60 - 120和空腹胰岛素密切相关，R值分别为 - 0.816和0.789（R² = 0.892，P<0.01）。相关分析结果显示，在4周组，肾周脂肪组织中NPY基因mRNA表达水平与GIR60 - 120、空腹胰岛素和游离脂肪酸密切相关，R值分别为 - 0.765、0.716和0.657（P<0.01）。在12周组，肾周脂肪组织中NPY基因mRNA表达水平与GIR60 - 120、空腹胰岛素和游离脂肪酸密切相关，R值分别为 - 耐0.853、0.622和0.608（P<0.01）。
肾周脂肪组织中NPY基因mRNA表达与胰岛素抵抗指标密切相关。它是影响胰岛素敏感性的重要因素。
