尿素浓度对粉核油球藻Pinguiococcus pyrenoidosus CCMP 2078生长和二十碳五烯酸积累特性的影响

目的探索不同尿素浓度对粉核油球藻(Pinguiococcus pyrenoidosus CCMP 2078)生长、脂肪酸组成、二十碳五烯酸(EPA)和多不饱和脂肪酸(PUFAs)含量的影响。方法采用GC-MS测定脂肪酸组成和含量。结果以尿素为氮源,氮浓度低于0.069 mmol.L-1时,藻几乎不生长;氮浓度为1.38 mmol.L-1时的细胞密度、干重和比生长率最高,随氮浓度继续升高,藻生长受到明显抑制。不同氮浓度条件下的脂肪酸组成不同。氮浓度为1.38 mmol.L-1的培养条件下,粉核油球藻的EPA和PUFAs含量最高,分别为15.66%和28.65%。在0.0069~1.38 mmol.L-1的氮浓度范围内,EPA和PUFAs含量随着氮浓度的增加而上升;而在1.38 mmol.L-1~5.52 mmol.L-1的氮浓度范围内,EPA和PUFAs含量随着氮浓度的增加而下降。结论采用1.38 mmol.L-1的尿素浓度进行藻的培养可以提高粉核油球藻P.pyrenoidosus CCMP 2078的EPA含量。     

Fat-1转基因小鼠的研究进展

多不饱和脂肪酸(PUFAs)为人体必需脂肪酸,与人体健康密切相关,其中主要分为n-6和n-3两大类,在哺乳动物中n-6和n-3不能自身合成,只能通过饮食获取。人体内n-6/n-3 PUFAs比例均衡,是人类保持健康的一个重要组成部分。为了研究n-6/n-3 PUFAs的比例在疾病中的预防作用,研究者培育了可自身将体内n-6转化为n-3的fat-1转基因小鼠,解决了以往研究PUFAs只能通过对动物喂养富含n-3和n-6饲料的不便。因而,fat-1小鼠可以作为一种理想的动物模型去研究在不改变饮食结构的状态下,体内的n-6/n-3 PUFAs比例的生物学作用。本文将对fat-1转基因小鼠的研究现状进行综述。     

n-3多烯脂肪酸与心血管病

<正> 心血管病包括冠心病、高血压、心功能不全、心肌梗塞、血栓形成和心律失常等一系列发生在心脏和血管系统的病症,为常见病和多发病,对人体健康的威胁很大,且有随人们寿命延长及营养改善逐渐发展的趋势,人们急于探出更多和更有效的防治药品。70年代初,流行病学调查发现格陵兰爱斯基摩人很少患心血管病,深入研究分析证明,是由于他们长期食用海鱼等海生动物所致,因此引起了广泛地注意,并研究海生动物与心血管病的关系。一、n-3多烯脂肪酸n-3多烯脂肪酸(n-3 polyunsaturatedfatty acids,n-3 PUFAs)又称ω-3多烯脂肪酸,它们的不饱和键自脂肪酸碳链甲基端第3位碳开始,如图 1所列α-亚麻酸(α-linolenicacid)、甘碳五烯酸(cicosapentaenoic acid,     

ω-3多不饱和脂肪酸治疗非酒精性脂肪性肝病的研究进展

非酒精性脂肪性肝病(nonalcoholic fatty liver disease,NAFLD)是由多种危险因素,如营养过剩、胰岛素抵抗(insulin resistance,IR)及相关代谢紊乱等诱导的慢性肝损伤,是代谢综合征在肝脏的病理表现。其病程的进展表现为非酒精性单纯性脂肪肝(nonalcoholic simple fatty liver,NAFL)、非酒精性脂肪性肝炎(nonalcoholic steatohepatitis,NASH)、脂肪性肝纤维化和脂肪性肝硬化。NAFLD患病率逐年升高,已成为我国最常见的慢性肝病之一。NAFLD的治疗主要为增加运动、健康饮食等基础治疗,药物治疗尚未达成共识。ω-3多不饱和脂肪酸(ω-3 polyunsattrated fatty acids,ω-3PUFAs)具有调节血脂的功能。NAFLD患者ω-3PUFAs水平较低,增加饮食中的ω-3PUFAs可以延缓病情进展,改善肝脏脂代谢的失衡和肝细胞的炎性损伤。本文主要就ω-3PUFAs对NAFLD治疗的研究进展作一综述。     

n-3多不饱和脂肪酸在不同疾病中的研究进展

<正>n-3多不饱和脂肪酸(n-3PUFAs)指多不饱和脂肪酸中第1个不饱和键出现在碳链甲基端的第3位,对人体健康状况起着重要的作用,n-3PUFAs主要包括α-亚麻酸(α-linolenic aicd,ALA,18:3n-3),二十碳五烯酸(eicosapentaenoic acid,EPA,20:5n-3),二十二碳六烯酸(docosahexaenoic acid,DHA,22:6n-3)等,其中含丰富的α-亚麻酸是人体     

冠状动脉粥样硬化性心脏病与血脂的关系

为了便于乡村医生了解血脂水平与冠状动脉粥样硬化性心脏病的因果关系,现介绍有关血脂的几个问题供参考。1 血脂血浆中脂质包括总胆固醇(TC)、甘油三酯(TG)、磷脂和非酯化脂肪酸。除非酯化脂肪酸与清蛋白结合外,不溶于水的脂类则与血浆中的球蛋白结合形成脂蛋白(CP),能与脂质结合的球蛋白称载脂蛋白(Apo)。各种脂蛋白中蛋白质和脂质的含量不     

Raloxifene与利维爱对去卵巢大鼠血脂的影响

目的观察Raloxifene(EVISTA)和利维爱(Livial)用于治疗去卵巢大鼠骨质疏松时对血脂的影响。方法32只4月龄雌性SD大鼠随机分为4组 :假手术组、模型组、Raloxifene组及利维爱组 ,每组8只 ,用药60天 ,采血分离血清 ,测定血清总胆固醇(TC)、甘油三脂(TG)、高密度脂蛋白(HDL_C)、低密度脂蛋白(LDL_C) ,对各组血脂测定值进行比较。结果大鼠去卵巢75天后 ,模型组血脂已有变化 ,表现为TC增高 ,HDL_C降低 ,TC、LDL_C差异无显著性 ;两药物组与模型组比较血脂改善 ,但调脂结果各不相同 :利维爱与Raloxifene均有降低TG、升高HDL_C的作用 ,前者降TC强于后者 ,对LDL_C无明显影响 ;后者升HDL_C强于前者 ,同时还有降低LDL_C作用 ;二者对TG均无明显作用 ;结论大鼠去卵巢后将发生血脂紊乱 ,Raloxifene、利维爱均有调脂作用     

ω—3多不饱和脂肪酸与炎性疾病

ω-3多不饱和脂肪酸(ω-3 polyunsat-urated fatty acid,ω-3 PUFAs)是一类具有双键的长链脂肪酸,结构中的第一个双键起于碳链甲基端的第三、四碳原子之间。α-亚麻酸(α-linolenic acid),廿碳五烯酸(eicosapen-taenoic acid,EPA)和廿二碳六烯酸(docosa-hexaenoic acid,DHA)都属于此类。ω-3 PU-FAs在自然界的分配很不均恒。陆地动植物     

n-3多不饱和脂肪酸类药物在心血管疾病中的临床应用进展

许多临床试验表明n-3多不饱和脂肪酸(n-3 PUFAs)对于冠心病、血脂异常和心力衰竭等人群均具有保护作用,而且已有建议推荐心肌梗死后患者和高甘油三酯血症人群口服此类提纯药物。但在应用过程中,仍有一些值得临床关注的问题,如药物安全性、药物成分和用量等。笔者认为,随着对n-3 PUFAs药物的深入研究,其将有更广阔的应用前景。     

ω-3脂肪酸联合氯氮平药物治疗精神分裂症及对血脂的影响

目的:探讨ω-3脂肪酸联合氯氮平药物治疗精神分裂症及对血脂的影响.方法:研究对象选取我院2019年01月至2020年08月间收治的精神分裂症伴糖脂代谢异常者86例,根据治疗方案不同将其分为ω-3组(ω-3脂肪酸联合氯氮平,43例)和对照组(氯氮平联合安慰剂,43例),比较两组患者治疗前后的血脂和血糖的相关指标表达水平.结果:两组患者治疗前腰围、BMI比较,均无明显差异(P>0.05),对照组患者治疗后腰围、体重指数均明显高于ω-3组(allP<0.001);两组患者治疗前血糖、血脂相关指标比较,均无明显差异(P>0.05),对照组患者治疗后空腹血糖、低密度脂蛋白胆固醇、总胆固醇、三酰甘油均明显高于ω-3组(allP<0.001),高密度脂蛋白胆固醇明显低于ω-3组(P<0.001).结论:ω-3脂肪酸应用于精神分裂症患者可有效调节机体血糖、血脂水平,有助于控制病情进展.     

Fish oil fatty acids as cardiovascular drugs

Starting in the 1970s the hypothesis that the low mortality from coronary heart disease among the Greenland Eskimos was due to their high consumption of n-3 fish oil fatty acids, initiated many studies to find if the n-3 polyunsaturated fatty acids in fish oils (PUFAs) could prevent cardiac atherosclerosis. To date this possibility has not achieved clinical recognition. The recent literature shows an increase of intervention studies to learn if the fish oil fatty acids can reduce mortality from sudden cardiac death, and the mechanism(s) of such a protective effect. Indeed the most definite beneficial cardiac action of these n-3 PUFAs seems now to be their ability in the short term to prevent sudden cardiac death. It is apparent that over long periods of time the n-3 fish oil fatty acids also prevent atherosclerosis. Definition of the fatty acids to which I will be referring in the text: n-6 (omega-6) polyunsaturated fatty acids; linoleic acid (18:2n-6, LA); arachidonic acid (C20:4n-6, AA). n-3 (omega-3) fatty acids; alpha-linolenic acid (18:3n-3, ALA); eicosapentaenoic acid (20:5n-3, EPA); docosahexaenoic acid (C22:6n-3, DHA). The bold, underlined abbreviation will appear in the text to identify the fatty acid being discussed.     

Omega 3-fatty acids: health benefits and cellular mechanisms of action

Epidemiological evidence has established that ingestion of long-chain polyunsaturated omega-3 fatty acids (omega-3 PUFAs), abundant in fish oils, have profound effects on many human disorders and diseases, including cardiovascular disease and cancer. Here we briefly review the dietary recommendations and the food sources that are naturally enriched by these fatty acids. There are also a number of products including eggs, bread, and cereals available to supplement omega-3 fatty acid dietary intake. Some of these supplements are proposed to aid different pathological conditions. While the beneficial effects of omega-3 fatty acids can no longer be doubted, their molecular mechanism of action remains elusive. Without question, the action of omega-3 fatty acids is complex and involves a number of integrated signaling pathways. This review focuses on one of the possible cellular mechanisms by which the omega-3 PUFAs, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), may function. Studies with cancer cells suggest that DHA induces cell cycle arrest and apoptosis by activating protein phosphatases, leading to dephosphorylation of retinoblastoma protein (pRB). Protein phosphatases are also involved with the protein Bcl2, which regulates the release of cytochrome c from mitochondria, and eventually, activation of the apoptotic enzyme caspase 3.     

Effects of polyunsaturated fatty acids on calcium response and degranulation from RBL-2H3 cells

To investigate the biological activity of various polyunsaturated fatty acids (PUFAs) on the allergic reaction, we examined the effects of six PUFAs and two saturated fatty acids on calcium response and degranulation from rat basophilic leukemia (RBL-2H3) cells. Between 20 and 40 microM of six PUFAs (omega-6 series: arachidonic acid [AA, C20:4], gamma-linolenic acid [gamma-LN, C18:3] and linoleic acid [LA, C18:2]; omega-3 series: alpha-linolenic acids [alpha-LN, C18:3] and eicosapentaenoic acid [EPA, C20:5]; and omega-9 series: oleic acid [OLE, C18:1]), or two saturated fatty acids (stearic acid [STA, C18:0] and arachidic acid [AD, C20:0]) were used to examine the effects on calcium response and degranulation from RBL-2H3 cells. Calcium response was monitored using the fluorescent calcium indicator fura-2, while degranulation was monitored by measuring histamine release from the cells. Three omega-6 PUFAs (AA, alpha-LN and LA) dose-dependently increased the cytosolic free-calcium concentration and histamine release from RBL-2H3 cells. This phenomenon was specific to the omega-6 PUFAs, the omega-3 PUFAs (alpha-LA and EPA), omega-9 PUFA (OLE) and the saturated fatty acids (STA and AD) had no effect. The increase in the cytosolic free-calcium concentration caused by the omega-6 PUFAs depended on the existence of external calcium, cell viability and the cellular IP(3) levels remained unchanged throughout the experiment. These results suggest that omega-6 PUFAs work as direct mediators of calcium signaling pathways in RBL-2H3 cells.     

Inhibitory effects of saturated and polyunsaturated fatty acids on the cytochrome P450 3A activity in rat liver microsomes

This study was conducted to investigate the inhibitory effects of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) on cytochrome P450 3A (CYP3A). The inhibition of 6beta-hydroxy testosterone formation from testosterone in rat liver microsomes was used as an index of CYP3A activity. In the present study, among the three types of fatty acids, the rank order of inhibitory effects of fatty acids was SFAs相似文献   

Immunomodulatory effects of eicosapentaenoic acid through induction of regulatory T cells

Dietary intake of omega-3 polyunsaturated fatty acids (PUFAs) has been found to affect inflammation and metabolism, and many researchers have shown that omega-3 PUFAs provide benefits in immunologic and metabolic disorders. These effects were assumed to result mainly from a modification in the production of inflammatory mediators and the suppression of inflammatory leukocytes. Among PUFAs, eicosapentaenoic acid (EPA), a component of fish oil, apparently has the most potent effect. Recently, much research has focused on regulatory T cells (Tregs) as controllers of immune responses not only to self-antigens but also to non-self-antigens, including donor alloantigens. Therefore, induction of antigen-specific Tregs may be an attractive strategy for managing autoimmune diseases and transplant rejection. Peroxisome proliferator-activated receptor γ (PPARγ), a ligand-activated nuclear receptor that regulates lipid and glucose metabolism, can be activated by thiazolidinediones, fatty acids, and eicosanoids, including EPA. PPARγ was recently found to have immunoregulatory effects, and a PPARγ agonist inhibited immune responses in a rat model of autoimmune disease. Furthermore, in a murine model, one high dose of purified EPA given the day of transplantation induced marked prolongation of cardiac allograft survival in a dose-dependent manner. These findings suggest that EPA induced Tregs by means of a PPARγ-dependent mechanism. This review describes the immunomodulatory effects of PUFAs, especially EPA, and summarizes recent research that may have implications for the development of therapies for autoimmune diseases and transplant rejection that are based on induction of Tregs.     

Fatty acids, lipids, and cytochrome p-450 monooxygenase in hepatic microsomes of minks fed fish-based diets and exposed to Aroclor 1242.

Minks were fed different fish-based diets and exposed to 1 mg/d of the commercial polychlorinated biphenyl (PCB) mixture Aroclor 1242 for 4 wk (November-December 1995) or 21 wk (July-December 1998). In all the dietary groups, the PCBs increased hepatic phospholipid (PL) content. No significant increase was detected in hepatic triacylglycerols (TGs). In the minks fed the different fish diets, the PCBs caused qualitatively and quantitatively different changes in the microsomal fatty acids. In the minks that were fed a diet rich in fat and low in polyunsaturated fatty acids (PUFAs), the PCBs increased the percentage of oleic acid (18:1n-9, characteristic of the storage TGs) at the expense of n-3 PUFAs. This seemed to be due to inclusions of TGs in the membrane fragments and partly due to incorporation of TG-derived fatty acids into the membrane PLs. In addition, significant decrease of PUFAs was detected also in the hepatic TGs. The concomitant decrease in the concentrations of hepatic vitamin E suggested that lipid oxidation may also contribute to the decrease of the PUFAs. In the liver of the minks fed a low-fat but PUFA- and vitamin E-rich diet, the fatty acid changes due to the PCBs (the 21-wk exposure) remained small but the cytochrome P-450 system was significantly activated. In the minks fed Baltic herring (rich in organochlorines via the foodweb), the cytosolic glutathione S-transferase (GST) activity, levels of microsomal thiobarbituric acid-reactive substances (TBARS), and hepatic PLs were significantly elevated. In conclusion, in the mink the microsomal fatty acid changes were not directly connected with the ethoxyresorufin O-deethylase (EROD) activity or P-450 expression. Apparently, the PCBs produced definite fatty acid changes only in certain lipid matrices of tissue. In addition, a rich dietary supply of PUFAs and vitamin E may prevent these changes, even in a long-term subchronic exposure.     

Formation of cyclic deoxyguanosine adducts from omega-3 and omega-6 polyunsaturated fatty acids under oxidative conditions

The discovery of the cyclic 1,N(2)-propanodeoxyguanosine adducts of acrolein (Acr), crotonaldehyde (Cro), and t-4-hydroxy-2-nonenal (HNE) as endogenous DNA lesions from lipid peroxidation has raised questions regarding the role of different types of fatty acids as sources for their formation. In this study, we carried out reactions at pH 7 and 37 degrees C with deoxyguanosine 5'-monophosphate and omega-3 polyunsaturated fatty acids (PUFAs), including docosahexaenoic acid (DHA), linolenic acid (LNA), and eicosapentaenoic acid (EPA); or omega-6 PUFAs, including linoleic acid (LA) and arachidonic acid (AA), each in the presence of ferrous sulfate. The formation of Acr, Cro, and HNE-derived 1,N(2)-propanodeoxyguanosine adducts (Acr-, Cro-, and HNE-dG) in the incubation mixture was determined by reversed-phase HPLC analysis. The results showed that Acr and Cro adducts are primarily derived from omega-3 PUFAs, although Acr adducts are also formed, to a lesser extent, from oxidized AA and LA. HNE-dG adducts were detected exclusively in incubations with AA. The kinetics of the formation of these adducts was determined during incubations for 2 weeks and 5 days. The rate of Acr adduct formation was about 5-10-fold that of Cro adducts, depending on the type of PUFAs, and the rate of formation of HNE adducts from AA was also considerably slower than that of Acr adducts. Unlike other cyclic adducts, the formation of Acr adducts was independent of types of PUFAs, but its yield was proportional to the number of double bonds in the fatty acid. Only one of the isomeric Acr adducts was detected, and its stereoselective formation is consistent with that observed previously in vivo. Two previously unknown cyclic adducts, one derived from pentenal and the other from heptenal, were also detected as products from omega-3 and omega-6 fatty acids, respectively. This study demonstrated the specificity for the formation of the cyclic adducts of Acr, Cro, and HNE and other related enals by oxidation of omega-3 and omega-6 PUFAs. These results may be important for the understanding of the specific roles of different types of fatty acids in tumorigenesis.