耐力运动对高脂饮食小鼠一氧化氮及氧化型低密度脂蛋白水平的影响

目的:研究耐力性运动对高脂饮食小鼠血浆一氧化氮以及氧化型低密度脂蛋白水平的影响,探索耐力性运动是否有可能作为药物以外的预防动脉硬化的手段.方法:实验在天津体育学院实验中心完成.采用南京建成生物工程公司试剂盒测定一氧化氮浓度,依试剂盒说明书操作.氧化型低密度脂蛋白的测定方法如下:将血浆0.3 mL注入预先加入EDTA(100 mmol/L)的试管中,加入柠檬酸钠和肝素的混合溶液3 mL(柠檬酸钠0.064 mol/L,肝素5万U/L),震荡混匀后室温放置15 min,4 000 r/min离心15 min,弃上清,在沉淀物中加入Tris-HCL 0.3 mL(0.02 mol/L,pH值8.6)再次溶解,取再次溶解液0.3 mL依次加入乙酸1.5 mL(200 g/L),硫代巴比妥酸1.5 mL(8 g/L),震荡混匀后,沸水浴60 min,流水冷却后,加入正丁醇4 mL,强力震荡混匀,3 000 r/min离心5 min,532 nm波长下测定吸光度.结果:高脂饮食组动物血浆一氧化氮水平[(24.90±9.06)μmol/L]明显低于正常饮食组[(45.03±10.23)μmol/L](P＜0.05),而高脂饮食结合运动干预组动物血浆一氧化氮水平[(38.11±12.71)μmol/L]明显高于高脂饮食组(P＜0.05),并与正常饮食对照组相比无显著性差异(P＞0.05).另外,高脂饮食组动物血浆氧化型低密度脂蛋白水平[(4.13±0.66)μmol/L]明显高于正常饮食对照组[(2.04±0.52)μmol/L](P＜0.05),而高脂饮食结合运动干预组[(2.46±0.49)μmol/L]明显低于高脂饮食组(P＜0.05),并与正常饮食对照组无显著性差异(P＞0.05).结论:耐力性运动可有效的逆转高脂饮食造成体内一氧化氮水平的下降及氧化型低密度脂蛋白水平上升.

The present study aimed to examine roles of histamine neurons in leptin signaling pathways and leptin resistant states. H1-receptor knockout (H1KO) mice showed no change in daily food intake, adiposity, growth curve, basal expression of hypothalamic neuropeptides, uncoupling proteins (UCPs) or ob gene. However, H1KO mice fed with high fat diet increased fat deposition and ob gene expression more excessively. Leptin-induced feeding suppression was attenuated in H1KO mice. Chronic leptin treatment decreased visceral fat and up-regulated UCPs expression in brown and white fat. These effects of leptin were attenuated in pair-fed H1KO mice. Chronic histamine or histidine treatment decreased body weight, body fat deposition, and serum glucose and insulin in diet-induced obese, ob/ob and db/db mice. Activation of histamine neurons suppressed ob gene expression in the fat tissue together with elevation of seurm leptin and UCPs mRNA. These actions of neuronal histamine were attenuated in the double knockout mice, i.e., db/db mice with H1KO. Taken together, H1KO mice, a novel leptin resistant model, elucidate essential roles of H1-R in energy intake and expenditure as a down-stream-signaling message of leptin actions in the brain. The anti-obesity and anti-diabetic effects of histamine neurons provide a new insight into therapeutic strategies on human obesity and diabetes with leptin resistance.

Comparative study on the difference of obesity model induced by two kinds of high fat diet in Sprague-Dawley rats

Objective:To explore the differences of obese Sprague-Dawley (SD)rats model induced by lard oil high-fat (HF)diet or purified HF diet.Methods:SD weanling rats were randomly divided into three groups:D1 group,where rats were fed by lard oil HF diet;D2 group,where rats were fed by purified HF diet;C group,where rats were fed on chow.After 12 weeks,diet-induced obesity rats (top 33％ based on weight)were selected for further study,and the rest rats from group D1 and D2 were excluded.The food intake and weight were weighted daily and weekly,respectively.The subcutaneous,visceral and total fat contents of rats was measured by 256-row CT scan and the Lee index was calculated accordingly.The kidney,liver,testis,spleen and heart were weighted respectively.Serum leptin and insulin levels were quantified.The pathology in liver and adipose tissues were analyzed by HE staining.Oral glucose tolerance test (OGTT)was used to compare the glucose tolerance ability.Serum total cholesterol (T-CHO),high density lipoprotein (HDL-C),low density lipoprotein (LDL-C),triglyceride (TG)and inflammatory cytokines IL-6,TNF-α were detected as well.Results:After 12 weeks,the body weight,subcutaneous fat,visceral fat,total fat mass,wet weight of liver,kidney and heart,area under blood glucose curve and the levels of serum insulin,leptin,T-CHO,LDL-C,TG,IL-6 and TNF-α in group D2 were significantly increased compared to those of group C and group D1.HDL-C of group D2 was markedly lower than that in group C (P＜0.05).The visceral fat,total fat content and HDL-C in group D1 were significantly different from those of group C (P＜0.05).Steatosis and enlarged adipocyte were found in the livers of rats in group D1 and D2,and the lesions were more significant in group D2.Conclusion:Purified HF diet was more effective in inducing metabolic abnormalities,steatosis,peripheral chronic inflammation in obese SD rat models.But lard oil HF diet was more economical when only inducing visceral steatosis was required.