鱼胶原蛋白肽对高脂膳食小鼠肝脏脂肪代谢和氧化还原状态的影响

目的：研究鱼胶原蛋白肽（fish collagen peptides,FCPs）对高脂膳食（high-fat diet,HFD）小鼠肝脏脂肪代谢和氧化还原状态的影响。方法：54?只C57BL/6雄性小鼠按体质量随机分为正常膳食组（CON）、HFD组（HF）和FCPs干预HFD组（PHF）。每周记录各组小鼠体质量,并按体质量把每组小鼠随机均分为两批,分别在第11和22周宰杀,测定采食量、脂肪表观消化率;肝脏中甘油三酯（triglyceride,TG）、总胆固醇和游离脂肪酸（free fatty acid,FFA）含量;肝脏脂代谢相关基因乙酰辅酶A羧化酶1、脂肪酸合成酶、固醇调节元件结合蛋白1c、胆固醇7α-羟化酶（cholesterol 7α-hydroxylase 1,CYP7A1）、过氧化物激活受体α（peroxisome proliferator activated receptor α,PPARα）和肉毒碱棕榈酰基转移酶1（carnitine palmity1 transferase 1,CPT1）的mRNA表达水平,肝脏氧化还原状态相关指标活性氧自由基（reactive oxygen species,ROS）、丙二醛、总抗氧化能力（total antioxidant capacity,T-AOC）、谷胱甘肽过氧化物酶（glutathion peroxidase,GSH-Px）活力和还原型/氧化型谷胱甘肽的水平。结果：第22周时,与HF组相比,PHF组小鼠的采食量、脂肪和能量摄入显著增加（P＜0.05）,肝脏的TG、FFA、脂肪空泡和脂肪浸润面积比明显降低（P＜0.05）,脂肪分解关键基因CYP7A1、PPARα和CPT1的mRNA表达水平显著上调（P＜0.05）,肝脏的ROS水平显著降低（P＜0.05）,T-AOC水平和GSH-Px活力显著升高（P＜0.05）。结论：质量分数1% FCPs干预可能通过改善HFD小鼠肝脏氧化还原状态,促进肝脏脂肪分解代谢,起到减少小鼠肝脏脂肪蓄积和改善脂代谢。     

Effect of the long-term intake of an egg white hydrolysate on the oxidative status and blood lipid profile of spontaneously hypertensive rats

This paper examines the effects of the long-term consumption of egg white hydrolysed with pepsin (hEW) on the antioxidant status and lipid profile of spontaneously hypertensive rats (SHR). The antioxidant capacity was measured by the oxygen radical absorbance capacity (ORAC) and the oxidative status by the malon-dialdehyde (MDA) assay. The lipid profile was analysed spectrophotometrically. The radical-scavenging capacity of the plasma was increased and the MDA concentration in the aorta was decreased in the SHR treated with 0.5 g/kg/day of hEW. Our findings indicate that hEW played an important role in antioxidative defence of SHR and exerted a beneficial effect on the lipid profile, lowering triglycerides and total cholesterol without changing HDL levels. Therefore, hEW may be useful to prevent or reverse abnormalities associated with the metabolic syndrome and its complications, such as hypertension, oxidative stress and hyperlipidemia.     

硒蛋白及其对巨噬细胞功能调节作用的研究进展

硒蛋白作为体内硒的主要存在形式,在免疫反应等许多方面发挥重要的生理功能,而巨噬细胞则在免疫调节与抗微生物感染等方面具有关键作用。近年来,通过硒饲喂实验、基因敲除、单克隆抗体等多种实验手段,发现硒蛋白对巨噬细胞功能具有重要的调节作用。本文总结近年来硒蛋白在分子水平上,对巨噬细胞胞内的氧化还原水平、游走特征以及炎症反应影响,显示出硒蛋白在免疫反应中的复杂分子调节机制及未来的药用前景。     

苏尼特羊尾油对自发性高血压大鼠机能代谢的影响

旨在为羊尾油对动物健康效应的研究提供基础数据,创建了自发性高血压大鼠(SHR)模型,将8周龄SHR分为试验组苏尼特羊尾油组(Y组)、阴性对照大豆油组(D组)、阳性对照菜籽油组(C组)和芥花油组(J组),并分别饲喂添加10%相应油脂的饲料,记录日摄食量,每周测量血压,饲喂14周后解剖采血,摘取肝脏,检测血清血脂水平、肝脏功能指标和肝脏病理学特征。结果表明：第14周时,Y组雌、雄SHR日摄食量显著高于对照组(p<0.05),血压显著低于对照组(p<0.05); Y组SHR血清中总胆固醇、甘油三酯和低密度脂蛋白胆固醇含量以及谷丙转氨酶、谷草转氨酶、γ-谷氨酰转移酶和乳酸脱氢酶活性显著低于对照组(p<0.05),而高密度脂蛋白胆固醇含量显著高于对照组(p<0.05);C组和J组SHR肝脏病变严重,Y组SHR肝脏组织未出现病变。综上,与对照组植物油相比,苏尼特羊尾油具有缓和SHR血压升高、有效改善血脂和肝脏机能作用,是具有良好健康效应的动物性油脂。     

Milk from cows fed a diet with a high forage:concentrate ratio improves inflammatory state,oxidative stress,and mitochondrial function in rats

Excessive energy intake may evoke complex biochemical processes characterized by inflammation, oxidative stress, and impairment of mitochondrial function that represent the main factors underlying noncommunicable diseases. Because cow milk is widely used for human nutrition and in food industry processing, the nutritional quality of milk is of special interest with respect to human health. In our study, we analyzed milk produced by dairy cows fed a diet characterized by a high forage:concentrate ratio (high forage milk, HFM). In view of the low n-6:n-3 ratio and high content of conjugated linoleic acid of HFM, we studied the effects of this milk on lipid metabolism, inflammation, mitochondrial function, and oxidative stress in a rat model. To this end, we supplemented for 4 wk the diet of male Wistar rats with HFM and with an isocaloric amount (82 kJ, 22 mL/d) of milk obtained from cows fed a diet with low forage:concentrate ratio, and analyzed the metabolic parameters of the animals. Our results indicate that HFM may positively affect lipid metabolism, leptin:adiponectin ratio, inflammation, mitochondrial function, and oxidative stress, providing the first evidence of the beneficial effects of HFM on rat metabolism.     

Dynamics of lipid droplets in the endometrium and fatty acids and oxylipins in the uterine lumen,blood, and milk of lactating cows during diestrus

Our objective was to investigate the lipid content of uterus, blood plasma, and milk at early, mid, and late diestrus. Lactating cows (n = 30) had the estrous cycle and ovulation synchronized by administration of exogenous hormones. Cows were blocked by parity and assigned randomly to receive transcervical uterine flushing and biopsy on d 5 (early diestrus), 10 (mid diestrus) or 15 (late diestrus) of the estrous cycle. Flushing and endometrial biopsy were performed in the uterine horn ipsilateral to the corpus luteum. The recovered flushing was used for analyses of lipid composition by liquid chromatography-tandem mass spectrometry and the biopsy was used for investigation of lipid droplet abundance in endometrial cryosections using a neutral lipid fluorescent dye. In addition, blood and milk samples were collected from all cows on d 5, 10, and 15. All blood samples were used to measure the concentration of progesterone in plasma, and all milk samples were used to determine milk composition. Subsamples of blood plasma and milk were also used to evaluate the composition of fatty acids and oxylipins using the same methodology used for uterine flushing samples. The abundance of lipid droplets in the endometrium increased 1.9-fold from d 5 to 10, and 2-fold from d 10 to 15. Concentration of long-chain fatty acids and oxylipins in uterine flushing were, on average, 2.2 and 2.5 times greater in samples collected on d 15 compared with those collected on d 5 and 10. These differences were not observed in blood and milk, suggesting that accumulation of fatty acids and oxylipins in the uterus is regulated locally. In addition to concentration, the profile of individual fatty acids and oxylipins in uterine lumen changed substantially during diestrus. The main categories with increased abundance at late diestrus were mono- and polyunsaturated fatty acids, and oxylipins derived from arachidonic acid, dihomo-γ-linolenic acid, and docosahexaenoic acid. In conclusion, fatty acids and oxylipins accumulate in the uterine lumen during diestrus and might work as a mechanism to supply these lipids to the developing conceptus at late diestrus, when the onset of elongation occurs and substantial synthesis of biomass and cell signaling by lipid mediators are required.     

The effect of consumption of inulin‐enriched Turrón upon blood serum lipids over a 5‐week period

This study analysed the effects of consuming 30 g per day of ‘Jijona turrón’, a traditional Spanish Christmas nougat‐type confection, on the circulating lipid parameters. Turrón is made of toasted almonds, honey and sugar. To make this product more appealing to consumers who need to control their lipid or glucose levels, a new product containing inulin was developed. Macro‐ and micronutrient contents were similar in both turrón with (JTI) or without (JT) inulin. A study with thirty‐two volunteers was conducted, with a daily consumption of 30 g of either inulin‐containing or not‐inulin‐containing turrón for a total of 5 weeks. At the beginning and at the end of the study, the circulating lipid parameters were quantified. The volunteers consuming both types of products maintained their circulating cholesterol within normal levels; however, consumers of JT presented a slightly but significant 8% decrease in LDL cholesterol level. On the other hand, the group consuming JTI maintained the levels of glycosylated haemoglobin, while volunteers consuming JT presented low but significantly higher levels of glycosylated haemoglobin.     

牛初乳对子代雌鼠子宫结构及雌激素受体表达的影响

目的 研究妊娠期和哺乳期通过SD母鼠暴露于牛初乳及断乳后继续食用牛初乳对成年子代雌鼠子宫发育及雌激素受体(ERα和ERβ3)表达的影响.方法 将母鼠随机分成2组,牛初乳组和空白对照组.牛初乳组母鼠在交配前期、妊娠期和哺乳期食用含有牛初乳的饲料,仔鼠3周断乳后食用对应于母鼠的饲料至成年.空白组母鼠和仔鼠食用普通饲料.仔鼠成年后处死,取其血液,剥离子宫和卵巢称重,检测血清激素,子宫病理学检查;利用免疫组化法检测子鼠子宫内雌激素受体(ERα和ERβ)的表达.结果 牛初乳组子代雌鼠体重、卵巢和子宫脏体比与空白组相比差异无统计学意义(P＞0.05),血清中催乳素(PRL)含量显著高于对照组,差异有统计学意义(p＜0.05),其余激素含量两组间差异无统计学意义(P＞0.05),子宫组织结构无异常表现,子宫内雌激素受体ERα表达量高于空白组,ERβ表达量与空白组相近,但与空白组相比差异均无统计学意义(P＞0.05).结论 妊娠期和哺乳期暴露于子代的牛初乳不会对子代雌鼠子宫发育和雌激素受体表达产生不利影响.     

亚麻籽油调和油对高脂模型大鼠的降脂作用

研究亚麻籽油调和油对预防性大鼠脂质代谢紊乱模型的降脂作用。在测定亚麻籽油调和油理化特性的基础上,以采用高胆固醇和脂类饲料喂养动物形成脂质代谢紊乱动物模型为研究对象,将大鼠分为基础对照组、高脂对照组、花生油高脂对照组,高(3 g/kg.bw)、中(2 g/kg.bw)、低(1 g/kg.bw)剂量亚麻籽油调和油组,在大鼠灌胃给予受试品4周后,分别测定各组大鼠体重,血清中的甘油三酯、总胆固醇、高密度脂蛋白胆固醇的含量。亚麻油调和油符合国家食用调和油标准,结晶温度为-21.7℃,氧化诱导期为5.23h,脂肪酸组成中n-6脂肪酸与n-3脂肪酸比例为4∶1;动物实验结果表明,高血脂动物模型建立成功,饲喂亚麻籽油调和油后,与高脂对照组和花生油对照组大鼠相比,中、高剂量组血清中TC(总胆固醇)和TG(总甘油三酯)含量显著下降,HDL-C(高密度脂蛋白胆固醇)含量显著升高,但与模型对照组相比,仅中、低剂量亚麻籽油调和油组的体重呈显著性下降。亚麻籽油调和具有较好的氧化稳定性和抗冻性能;灌胃给予2、3g/kg.bw的亚麻籽油调和油对预防性大鼠脂质代谢紊乱模型具有降血脂作用。