Different n-6/n-3 polyunsaturated fatty acid ratios affect postprandial metabolism in normal and hypertriglyceridemic rats

Postprandial metabolism plays major roles in many pathological conditions.The n-6/n-3 polyunsaturated fatty acid(PUFA)ratio is closely related to various physiological disorders.This study aimed to investigate the effects of high fat meals with different n-6/n-3 PUFA ratios on postprandial metabolism in normal control(NC)and hypertriglyceridemia(HTG)rats.The postprandial response of triglyceride(TG)in HTG groups was higher than that in NC groups after different n-6/n-3 PUFA ratio meals.The HTG groups showed higher postprandial total cholesterol(TC)responses than NC groups after 1:1 and 20:1 ratio meals.The 5:1 n-6/n-3 PUFA ratio elicited lower postprandial responses of tumor necrosis factorα(TNF-α)than 1:1 and 10:1 ratios in HTG groups.The postprandial malondialdehyde(MDA)response was lower after a 5:1 n-6/n-3 PUFA ratio meal than 1:1 and 20:1 ratio meals in HTG groups.The 1:1 ratio resulted in a lower postprandial reactive oxygen species(ROS)level than 5:1 and 10:1 n-6/n-3 PUFA ratios in NC groups.The results showed that a low n-6/n-3 PUFA ratio improved postprandial dysmetabolism induced by a high fat meal in NC and HTG rats.A high n-6/n-3 PUFA ratio increased the difference in postprandial metabolism between NC and HTG rats.

Effects of dietary ratio of n-6 to n-3 polyunsaturated fatty acids on immunoglobulins, cytokines, fatty acid composition, and performance of lactating sows and suckling piglets

This experiment was conducted to investigate the effects of dietary ratios of n-6：n-3 polyunsaturated fatty acids （PUFA） on the performance of lactating sows and their piglets. Thirty pregnant Landrace sows were assigned to one of three treatments from d 108 of gestation until weaning （26-29 d） and were fed diets containing different ratios of n-6：n-3 PUFA including 3：1,9：1 and 13：1. The effects on sow and litter production traits were examined together with an assessment of sow body condition. No differences were detected among the treatments for the daily feed intake of sows or changes in sow weight and back-fat levels during lactation （P 〉 0.05）. Litter size at d 14 and d 21 were tended to increase in 3：1 treatment compared with 9：1 and 13：1 treatments （P 〈 0.10）. Litter weight gain （1.77 kg/d） from d 0 to d 14 was tended to increase in 9：1 groups compared with the other two treatments （P 〈 0.10）. A significant difference was observed for the content of a -linolenic acid, total n-3 PUFA, and the ratio of n-6：n-3 PUFA in the colostrum, milk, and piglets plasma （P 〈 0.01）. The effects of different ratios of n-6：n-3 PUFA in sow diets on colostrum, milk and piglet plasma immunoglobulin concentrations are studied. No difference was observed among treatments in the concentrations of IgM, and IgA in colostrum （P 〉 0.05）. A great significant difference for IgG concentration was observed among 3 group in colostrum. A great significant difference for IgA, and IgM （P〈 0.01） concentrations in piglet plasma at d14 and a significant difference for IgG（P 〈 0.05） was observed at d14. Furthermore, at d 21 of lactation, piglet plasma IgG and IgA concentration were greater in 3：1 compared with 13：1 group （P 〈 0.01）. In summary, the current study demonstrated that altering the ratio of n-6：n-3 PUFA in lactating sow diet had an effect on the immune component including immunoglobulin and cytokines, and it tended to increase the litter average daily gain and improve the immune status of piglets when dietary ratio of n-6：n-3 PUFA was 9：1.

Effects of the Ratio of n-6∶n-3 Polyunsaturated Fatty Acids in the Maternal Diet on Immunoglobulins,Fatty Acid Composition,and Performance of Lactating Sows and Suckling Piglets under Conditions of Low Maternal Energy Intake

This experiment was conducted to investigate the effects of different ratios of n-6 ∶ n-3 polyunsaturated fatty acids （PUFA） in sow diets on the performance of lactating sows and their piglets at low digestible energy intakes. Twenty-one pregnant Landrace sows were assigned to one of three diets from day 108 of gestation until weaning （26 to 29 d） ,containing n-6∶n-3 PUFA ratios of 3 ∶1,8 ∶1 and 11 ∶1. The effects on sow and litter production traits and on sow body condition were examined. There were no differences among treatments in daily feed intakes or in changes in sow weight and back-fat levels during lactation. Litter size,litter weight at birth and weaning and litter average daily weight gain were also unaffected by treatment. As expected, large differences were observed in n-6 and n-3 fatty acids in the colostrum and plasma of sows and piglets （P 〈 0. 01） . The ratio of n6 ∶ n-3 PUFA the diet was positively correlated with those in colostrum,sow plasma and piglet plasma （R 2= 0. 55,0. 80 and 0. 80,respectively） . Sow plasma insulin and IGF-I levels at weaning were unaffected by the treatments. Plasma leptin （P 〈 0. 05） concentrations were increased in sows fed the diet with a n-6∶n-3 ratio of 8 ∶ 1. Immunoglobulin concentrations in colostrum were not altered by dietary treatment. Plasma IgG concentrations at d 14 were highest in piglets from sows fed the 8 ∶ 1 ratio of n-6∶n-3. Furthermore,this group had the highest IgA concentrations at day 21 of lactation compared with the other two groups （P 〈 0. 05） . In summary,our study demonstrated that at low digestible energy levels,altering the ratio of n-6 ∶ n-3 PUFA in the diets for lactating sows affected immune components and the fatty acid composition of lactating sows and their piglets. Further studies are needed to examine whether higher levels of fat supplementation than those used in the present study （1. 5%） can successfully enhance performance.

Beneficial n-3 polyunsaturated fatty acid levels and n6:n3 ratios after 4-week EPA + DHA supplementation associated with reduced CRP: A pilot study in healthy young adults

Chronic systemic inflammation is associated with many conditions of aging such as atherosclerosis. Lowering high n-6:n-3 polyunsaturated fatty acid (PUFA) ratios are commonly found in Western diets aids in preventing inflammatory-related diseases. However, it is not clear whether dietary interventions designed to alter n-6:n-3 PUFA ratios can reduce systemic inflammation in younger adults. Studies that evaluate PUFA intake often use subjective data from food frequency questionnaires or food records rather than more precise physiological measures of PUFAs (e.g. plasma levels). Therefore, the purpose of this pilot study that analyzed data from the experimental parent study of younger adults (n = 18), was to determine whether plasma PUFA levels were associated with levels of C-reactive protein (CRP), an inflammatory marker, and if supplementation with n-3 PUFAs was correlated with rising n-3 PUFA concentrations in plasma and decreasing n-6:n-3 ratios. In the parent study, participants received daily either placebo or n-3 PUFA softgels (1.6 g eicosapentaenoic acid [EPA] and 1.2 g docosahexaenoic acid [DHA]). EPA and DHA are the biologically active components in fish oil. Measures included blood for PUFA quantification at baseline and four weeks later, when blister wounds were created and wound fluid and saliva were collected. The saliva samples were used to measure CRP in the present study. We report that CRP was significantly and negatively correlated with total n-3 PUFAs (tau-β = ?0.373, p = 0.031) and positively correlated with n-6:n-3 ratios (tau-β = 0.320, p = 0.063). Those consuming EPA + DHA supplements had significantly higher concentrations of total n-3 PUFAs and significantly lower n-6:n-3 ratios (p The present study has shown that beneficial levels of n-3 PUFAs and n-6:n3 ratios were achieved with 4-weeks of EPA + DHA supplementation and were associated with reduced CRP in young adults. EPA + DHA supplementation for some young adults may help prevent inflammatory conditions later in life.

Novel Lipase from Golden Pompano(Trachinotus ovatus)Viscera:Purification,Characterization,and Application in the Concentrating of n-3 Polyunsaturated Fatty Acids

Lipases have been widely applied in a variety of industrial fields,such as food,pharmaceuticals,biofuels,and biotechnology.Recent years have witnessed a great interest in modifying lipids for the production of triacylglycerols enriched with n-3 polyunsaturated fatty acids(PUFAs).Here,a novel salt-tolerant,organic solvent-stable,and bile salt-activated lipase was purified from golden pompano(Trachinotus ovatus)viscera,which was named as golden pompano lipase(GPL).GPL had a specific activity of 57.2U mg^(-1)with an estimated molecular weight of 14 k Da,exhibited optimal activity at 40℃a nd pH 8.0,and showed K_(m)and V_(max)of 40.16μmol L^(-1)and 769.23μmol L^(-1)min^(-1),respectively.GPL activity was enhanced by Mn^(2+)and sodium deoxycholate.It was active in organic solvents,including methanol,ethanol,chloroform,and hexane.GPL also showed a good salinity tolerance of up to 1 mol L^(-1).n-3PUFA enrichment in the glyceride fraction of golden pompano oil was performed by GPL-catalyzed hydrolysis and yielded a total PUFA concentration of 56.99%.EPA,DHA,and DPA were enriched by 10.4-,3.2-,and 1.8-fold of their initial levels,respectively.This study recognized the industrial applicability of GPL to prepare enriched C_(20-22)n-3 PUFA.

The Relationships between Erythrocyte Membrane n-6 to n-3 Polyunsaturated Fatty Acids Ratio and Blood Lipids and C-reactive Protein in Chinese Adults:An Observational Study

Objective To investigate the relationships between erythrocyte membrane n-6：n-3 PUFAs ratio and blood lipids and high sensitivity C-reactive protein （hs-CRP）. Methods The Chinese and a observational study consisted of a population-based cross-sectiona subsequent 1-year follow-up study of 171 subjects with the fasting cholesterol of 5.13-8.00 mmol/L. study of 456 plasma total Results In the cross-sectional analysis, plasma low-density lipoprotein cholesterol （LDL-c） had a significant and negative association with the erythrocyte membrane n-6：n-3 PUFAs ratio （P for trend=0.019） after adjusting for sex, age and total PUFA percentage. In the follow-up study, 171 subjects were categorized into quartiles by the changes of n-6：n-3 ratio in erythrocyte membrane （△=month 12-month 0）. In the top quartile whose ratios of n-6：n-3 increased by an average of 1.25 during the follow-up, the LDL-c-lowering extent was 3.3 times of that in the lowest quartile whose ratios of n-6：n-3 decreased by an average of 1.13 （-1.07 mmol/L v.s. -0.32 mmol/L）. The hsCRP decreased by 0.11 mg/dL in the lowest quartile while increasing by 0.10 mg/dL in the top quartile （P for difference=0.052）. Conclusion Our results suggested that the balance between n-6 and n-3 fatty acids may optimize the cardiovascular benefits from dietary PUFAs.

添加植物油降低饲粮n-6/n-3多不饱和脂肪酸比值对生长肥育猪脂肪沉积和脂肪酸组成及脂代谢相关基因表达的影响

本试验旨在研究饲粮添加植物油降低n-6/n-3多不饱和脂肪酸(PUFA)比值对生长肥育猪脂肪沉积和脂肪酸组成及脂代谢相关基因表达的影响。试验选用54头体重[(45.30±1.72)kg]相近的“杜×长×大”三元杂交猪,随机分为3组,每组6个重复,每个重复3头。对照组饲喂基础饲粮,试验组分别饲喂含4.5%菜籽油(菜籽油组)和4.5%混合油(混合油组,菜籽油∶亚麻籽油=1∶1)的饲粮。3组饲粮粗脂肪含量分别为2.76%、7.24%和7.24%,n-6/n-3 PUFA比值分别约为10∶1、4∶1和2∶1,消化能和粗蛋白质含量基本相同。预试期7 d,正试期42 d。结果表明:1)与对照组相比,饲粮添加植物油显著提高生长肥育猪背最长肌肌内脂肪(IMF)含量(P<0.05),对平均日增重(ADG)、平均日采食量(ADFI)、料重比(F/G)及背膘厚无显著影响(P>0.05)。2)与对照组相比,饲粮添加植物油显著提高背最长肌和皮下脂肪n-3及总PUFA含量(P<0.05),降低n-6/n-3 PUFA比值(P<0.05);与菜籽油组相比,混合油组背最长肌和皮下脂肪n-3 PUFA含量显著提高(P<0.05),n-6/n-3 PUFA比值显著降低(P<0.05)。3)与对照组相比,饲粮添加植物油显著提高背最长肌和皮下脂肪组织脂肪酸转位酶/CD36(FAT/CD36)和脂肪酸转运蛋白1(FATP1)mRNA相对表达量(P<0.05),且混合油组背最长肌FAT/CD36和脂肪酸转运蛋白4(FATP4)mRNA相对表达量显著高于菜籽油组(P<0.05)。4)与对照组相比,饲粮添加植物油显著提高背最长肌碳水化合物反应元件结合蛋白(ChREBP)、葡萄糖转运子4(Glut4)及脂肪酸合酶(FAS)、乙酰辅酶A羧化酶(ACC)、脂肪酸延伸酶5(Elovl5)和脂肪酸延伸酶6(Elovl6)等生脂基因mRNA相对表达量(P<0.05),显著降低皮下脂肪组织过氧化物酶体增殖物激活受体γ(PPARγ)、维甲酸X受体α(RXRα)及生脂基因mRNA相对表达量(P<0.05)。综上所述,添加植物油降低饲粮n-6/n-3 PUFA比值可上调FAT/CD36和FATP1表达,促进猪肌肉和皮下脂肪组织吸收和利用饲粮长链脂肪酸合成脂肪;下调PPARγ及生脂基因表达,抑制皮下脂肪组织从头脂肪合成,而上调ChREBP及生脂基因表达,促进背最长肌脂肪合成,提高IMF含量,且饲粮n-6/n-3 PUFA比值为2∶1时能更有效地改善组织n-3 PUFA含量和n-6/n-3 PUFA比值。

饲料中n-3 PUFA/n-6 PUFA比值对罗氏沼虾幼虾生长性能和抗氧化能力的影响

为探讨饲料多不饱和脂肪酸n-3 PUFA/n-6 PUFA比值对罗氏沼虾幼虾生长性能、虾体肌肉组成、抗氧化能力、血清生理指标以及消化能力的影响,实验设计了n-3 PUFA/n-6PUFA比值分别为0.37(D1)、0.59(D2)、0.93(D3)、1.51(D4)和4.38(D5)的5种等氮等脂饲料饲喂罗氏沼虾幼虾8周,每组设4重复,每个重复40尾虾。结果显示,饲料n-3PUFA/n-6 PUFA比值对罗氏沼虾幼虾存活率(SR)无显著影响;实验虾终末体重(FW)、增重率(WGR)和特定生长率(SGR)随饲料n-3 PUFA/n-6 PUFA比值增加先升后降,均在D3组最高;且D3组虾有最大的肝胰腺蛋白酶活性及脂肪酸合成酶活性。虾体肌肉粗蛋白质、水分和灰分含量不受饲料n-3 PUFA/n-6 PUFA比值影响,但总脂肪含量在D3组显著高于其他组;各组虾体肌肉的n-3 PUFA/n-6 PUFA比值的变化趋势与饲料的n-3 PUFA/n-6PUFA比值变化趋势呈正相关。随饲料n-3 PUFA/n-6 PUFA比值增加,实验虾血清和肝胰腺中超氧化物歧化酶(SOD)活性、总抗氧化能力(T-AOC)和血清铜蓝蛋白(CP)含量均呈现先升后降趋势,并在n-3 PUFA/n-6 PUFA比值为0.93~1.51时达到最大,但丙二醛(MDA)含量持续上升;D1组血清总胆固醇(T-CHO)和甘油三酯(TG)含量显著高于其他组;血清谷草转氨酶(AST)和谷丙转氨酶(ALT)活性先降后升,且D3组最低。研究表明,饲料适宜的n-3 PUFA/n-6 PUFA可显著提升罗氏沼虾生长性能和抗氧化能力,对增重率和特定生长率进行折线回归,建议罗氏沼虾幼虾饲料中最适n-3 PUFA/n-6 PUFA比值为0.86~0.94。

Anti-inflammatory and Immunomodulatory Effects of Marine n-3 Polyunsaturated Fatty Acids on Human Health and Diseases

The pharmaceutical effects of n-3 polyunsaturated fatty acids(n-3 PUFAs) as dietary nutrients on human health and diseases have gained much attention and are investigated for decades. Docosahexaenoic acid(DHA), eicosapentaenoic acid(EPA) and docosapentaenoic acid(DPA) are the three major n-3 PUFAs enriched in marine organisms, such as fish, shrimp, algae, and so on. It has been well known that n-3 PUFAs, especially DHA and EPA, are beneficial in reducing the risk of cardiovascular and cerebrovascular diseases. Accumulating evidence suggests that n-3 PUFAs might cure inflammatory diseases through several mechanisms, such as plasma membrane remodeling of lymphocytes, down-regulating pro-inflammatory cytokines, and alternating adhesion molecule expressions. Several molecular targets of n-3 PUFAs on immune-regulation have also been identified, such as GPR120(FFA4), protein kinase C(PKC), and PPAR-γ. However, it remains inconclusive if dietary n-3 PUFAs function the same both in vitro and in vivo based on cohort studies. This review will focus on the molecular targets and mechanisms of anti-inflammatory and immunomodulatory effects of n-3 PUFAs on human health and diseases, such as obesity, tumor, diabetes, and autoimmune diseases.

Recent advances in liver preconditioning: Thyroid hormone, n-3 long-chain polyunsaturated fatty acids and iron

Liver preconditioning (PC), defined as an enhanced tolerance to injuring stimuli induced by previous specific maneuvers triggering beneficial functional and molecular changes, is of crucial importance in human liver transplantation and major hepatic resection. For these reasons, numerous PC strategies have been evaluated in experimental models of ischemia-reperfusion liver injury, which have not been transferred to clinical application due to side effects, toxicity and difficulties in implementation, with the exception of the controversial ischemic PC. In recent years, our group has undertaken the assessment of alternate experimental liver PC protocols that might have application in the clinical setting. These include thyroid hormone (T3), n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA), or iron, which suppressed liver damage due to the 1 h ischemia-20 h reperfusion protocol. T3, n-3 LCPUFA and iron are hormetic agents that trigger biologically beneficial effects in the low-dose range, whose multifactorial mechanisms of action are discussed in the work.

The Efficacy of the Consumption of n-3 Polyunsaturated Fatty Acids for the Maintenance of Remission in Patients with Inflammatory Bowel Disease

The aim of the present study was to investigate the efficacy of the actual consuming n-3 PUFA for remission-maintenance in IBD patients. A questionnaire on the dietary habits of patients one month before hospitalization (Q1) was completed by 24 patients with IBD (10 ulcerative colitis (UC) subjects and 14 Crohn’s disease (CD) subjects) treated at our hospital. We educated the study subjects about an n-3 PUFA diet, and a follow-up survey (Q2) was conducted 6 to 12 months after discharge. Disease activity was evaluated using the International Organization for the Study of Inflammatory Bowel Disease (IOIBD) score and/or the Crohn’s Disease Activity Index (CDAI) score for CD and the partial UCDAI score without endoscopic evaluation for UC. Q1 showed that the average n-3 and n-6 PUFA intakes were 1673 ± 1651 mg and 9146 ± 5217 mg, respectively, and the average n-3/n-6 ratio was 0.27 ± 0.31. In Q2, the intake of n-3 PUFA was significantly higher (3671 ± 1684 mg, p < 0.001), whereas the n-6 PUFA intake decreased significantly (5217 ± 1973 mg, p < 0.001) compared to those in Q1. As a consequence, the dietary n-3/ n-6 ratio was significantly increased (0.87 ± 0.60, p < 0.001). Maintenance of the remission rate was significantly higher in IBD patients who complied with the n-3 diet, and these patients maintained a dietary n-3/n-6 ratio of 0.432 or higher (17 of 23 cases;70.8%, p < 0.03) compared to that observed for IBD patients who did not comply with the diet. These results emphasize the importance of adjusting dietary PUFA and suggest that the n-3 diet may be effective in maintaining the remission of IBD.

饲料n-3/n-6脂肪酸比值对军曹鱼生长及鱼体组织脂肪酸组成的影响

以精制鲽鱼油和豆油分别作为n-3及n-6系列脂肪酸源,配制5种不同n-3/n-6脂肪酸比值的饲料,进行连续8周饲喂军曹鱼幼鱼试验。结果表明,当饲料中的n-3/n-6脂肪酸比值为2.57时,军曹鱼的增重率和饲料效率最高;饲料中不同n-3/n-6脂肪酸比值对军曹鱼血清5项生理指标的影响不显著,但随着n-3/n-6脂肪酸比值的降低,血清中的谷丙转氨酶、谷草转氨酶、胆固醇含量表现出下降趋势;饲料中n-3、n-6多不饱和脂肪酸含量,与军曹鱼肌肉和肝脏的n-3、n-6多不饱和脂肪酸含量呈正相关。统计分析表明,军曹鱼饲料中适宜的n-3、n-6脂肪酸比例为2.98∶1。

Effects of n-3 Fatty Acids Supplementation on Performance, Relative Organ Weight and Fatty Acid Composition of Thigh Meat in Broiler Chickens

This study was conducted to evaluate the effects of dietary supplementation with marine microbe accumulating n-3 fatty acids on growth performance, relative organ weight and fatty acid composition of thigh meat in broilers. A total of 480 broilers were randomly allotted to three treat-ments with eight replications per treatment and 20 chicks per pen. A corn-soybean meal-based diet was formulated as a control diet and the broilers were then provided with one of the following dietary treatments:(1) CON(basal diet);(2) N0.1(basal diet+0.10% marine microbe accumulating n-3 fatty acids);(3) N0.2(basal diet+0.20% marine microbe accumulating n-3 fatty acids). No significant differences were observed in the growth performance or the relative organ weight among treatments. However, the levels of saturated fatty acids(SFA) and monounsaturated fatty acids(MUFA)were significantly lower(P<0.05) in groups that received the n-3 fatty acids treatments, whereas polyunsaturated fatty acids(PUFA) were increased(P<0.05) significantly in these groups. Overall, these results indicate that dietary supplementation with marine microbe accumulating n-3 fatty acids can increase PUFA and decrease SFA and MUFA in thigh meat.

n-6／n-3脂肪酸配方油对大鼠血脂和脂质过氧化的影响

目的研究不同脂肪酸n-6／n-3组成的配方油对大鼠血脂和脂质过氧化的影响。方法成年SD雄性大鼠喂饲含相同胆固醇(0.5％,W／W)、饱和脂肪酸(占供给能量10％)、单不饱和脂肪酸(占供给能量13％)和多不饱和脂肪酸(占供给能量12％),但不同脂肪酸n-6／n-3比(6.48、2.07、0.93、031)的4种配方油的高脂合成饲料60天,观察大鼠血脂及脂质过氧化的变化。结果 4种配方油比猪油均显著降低血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、LDL-C／HDL-C、AI[TC-HDL-C／HDL-C,致动脉粥样硬化指数)],升高HDL-C／TC；配方油D具有独特的升高血清HDL-C_2的作用；配方油A、C、D显著降低血清TG,而配方油B作用不明显。以n-3多不饱和脂肪酸占优势的配方油C、D比以n-6多不饱和脂肪酸占优势的配方油A、B显著地升高血清丙二醛,降低血清超氧化物歧化酶、全血谷胱甘肽过氧化物酶活性。4组配方油大鼠的心、脑脂褐质含量均比实验前增高,各配方油间无显著差异；心、脑脂褐质与血脂的相关分析发现心、脑脂褐质与血清TC、LDL-C呈正相关,与血清高密度脂蛋白胆固醇(HDL-C)、甘油三酯(TG)关系不明显。结论从预防动脉粥样硬化的角度,脂肪酸n-6／n-3比在2.07～6.48范围内是合理的脂肪酸供给模式。

膳食中高n-6/n-3多不饱和脂肪酸比值对小鼠精子浓度及活度的影响

目的近年来男性精子数量、质量呈下降趋势。文中研究小鼠膳食中高n-6/n-3多不饱和脂肪酸比值对其精子浓度及活度的影响。方法健康的B6小鼠20只,随机数表法分成对照组(基础饲料)和实验组(基础饲料+10%花生四烯酸),每组10只。喂食8周后,取各组小鼠附睾尾检测小鼠精子浓度及活度的变化,观察小鼠附睾组织显微结构的改变。结果实验组小鼠血清中α-亚麻酸、二十碳五烯酸、二十二碳六烯酸、二十二碳五烯酸、亚油酸含量均较对照组明显下降(P<0.01),而花生四烯酸和n-6/n-3 PUFAs明显升高(P<0.01)。实验组精子浓度(7×106个/mL)较对照组(80×106个/mL)显著下降,实验组精子活度(27%)较对照组(86%)显著下降,差异有统计学意义(P<0.01)。附睾组织管腔中精子数目明显减少。结论膳食中高n-6/n-3多不饱和脂肪酸比值对精子数量、质量具有显著损伤作用。

n-6/n-3多不饱和脂肪酸不同比例对乳腺癌细胞脂代谢调控基因的影响

目的探讨不同n-6/n-3多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）构成对乳腺癌细胞脂代谢调控基因及MAPK活性的影响.方法选用MCF-7（ER＋）和MDA-MB-231（ER-）乳腺癌细胞为实验对象,用不同n-6/n-3 PUFA构成（1～10）处理细胞后,MTT法观察细胞增殖能力,RT-PCR分析细胞脂代谢关键性调控基因（COX-2、5-LOX、PPARβ和PPARγ）表达变化,Western blot检测细胞MAPK蛋白磷酸化水平.结果 MCF-7细胞不表达COX-2基因.与对照组相比,单纯n-6和10：1 n-6/n-3 PUFA能明显促进这两种乳腺癌细胞增殖,诱导细胞COX-2、5-LOX、PPARβ和PPARγmRNA表达上调,并促进细胞MAPK磷酸化（P＜0.01）;与之相反的是,单纯n-3和1：1 n-6/n-3 PUFA显著抑制细胞生长,下调细胞COX-2、5-LOX、PPARβ和PPARγ mRNA表达,并抑制细胞MAPK磷酸化（P＜0.01）;但5：1 n-6/n-3 PUFA效果不明显.结论 n-6/n-3 PUFA不同比例对MCF-7和MDA-MB-231乳腺癌细胞脂代谢调控基因及信号转导的影响是不同的.在n-6/n-3比值为1～10范围内,单纯n-3和1：1 n-6/n-3能明显抑制脂代谢基因表达及信号转导,发挥显著抗乳腺癌细胞增殖效应.

n-6/n-3多不饱和脂肪酸不同比例对乳腺癌细胞膜脂组成和膜功能的影响

目的:观察n-6/n-3多不饱和脂肪酸(polyunsaturated fatty acid,PUFA)不同比例对乳腺癌细胞增殖能力、膜脂构成和膜功能的影响。方法:n-6/n-3PUFA不同比例处理MCF-7和MDA-MB-231乳腺癌细胞,气相色谱法分析细胞膜脂构成,共聚焦显微镜监测细胞膜流动性、膜电位和Ca2+跨膜内流。结果:单纯n-6和10∶1n-6/n-3PUFA组细胞膜较对照组含有更多的C18∶2和C20∶4,无n-3PUFA蓄积;但单纯n-3和1∶1n-6/n-3PUFA组细胞膜EPA含量显著增加,且未检测到C20∶4。另外,单纯n-6和10∶1n-6/n-3PUFA组可增加两种乳腺癌细胞的膜流动性,并诱导膜去极化和细胞外Ca2+内流;而单纯n-3和1∶1n-6/n-3PUFA组则降低细胞膜流动性,诱导细胞膜超极化改变和减缓细胞外Ca2+内流。结论:不同比例n-6/n-3PUFA明显改变MCF-7和MDA-MB-231乳腺癌细胞膜脂组成、膜流动性、超极化和Ca2+内流,这些改变可能参与其影响乳腺癌细胞生长的分子机制。

饲粮n-6/n-3多不饱和脂肪酸比值对冬毛期北极狐生长性能及肝脏脂肪酸代谢相关蛋白基因表达的影响

本试验旨在研究饲粮n-6/n-3多不饱和脂肪酸(PUFA)比值对冬毛期北极狐生长性能、肝脏脂肪酸组成及肝脏型脂肪酸结合蛋白(L-FABP)和脂肪酸转运蛋白(FATP)基因表达的影响。试验选取48只157日龄、平均体重为(5 658±47)g的健康雄性北极狐,随机分成4组,每组12个重复,每个重复1只。Ⅰ组饲粮中添加12.00%鱼油和2.00%豆油,n-6/n-3 PUFA比值为3.00;Ⅱ组饲粮中添加9.38%玉米油和4.62%豆油,n-6/n-3 PUFA比值为18.03;Ⅲ组饲粮中添加12.00%玉米油和2.00%豆油,n-6/n-3 PUFA比值为40.83;Ⅳ组饲粮中添加1.50%鱼油和12.50%玉米油,n-6/n-3 PUFA比值为136.36。各组饲粮除油脂组成和配比不同外,其他原料一致。预试期7 d,正试期40 d。结果表明:1)饲粮n-6/n-3 PUFA比值对冬毛期北极狐的平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G)有极显著影响(P<0.01)。Ⅰ和Ⅳ组的ADG极显著高于Ⅱ和Ⅲ组(P<0.01),Ⅰ、Ⅱ和Ⅳ组的ADFI极显著高于Ⅲ组(P<0.01),Ⅳ组的F/G极显著低于Ⅱ和Ⅲ组(P<0.01)。2)饲粮n-6/n-3 PUFA比值对冬毛期北极狐肝脏单不饱和脂肪酸(MUFA)、PUFA、n-3 PUFA和n-6 PUFA的含量有显著或极显著影响(P<0.05或P<0.01),对肝脏饱和脂肪酸(SFA)含量无显著影响(P>0.05)。Ⅰ和Ⅳ组肝脏n-3 PUFA含量极显著高于Ⅱ和Ⅲ组(P<0.01),Ⅱ和Ⅲ组肝脏n-6 PUFA含量极显著高于Ⅰ和Ⅳ组(P<0.01)。3)饲粮n-6/n-3 PUFA比值对冬毛期北极狐肝脏L-FABP mRNA相对表达量无显著影响(P>0.05),但极显著影响肝脏FATP mRNA相对表达量(P<0.01)。Ⅰ和Ⅳ组肝脏FATP mRNA相对表达量极显著高于Ⅱ和Ⅲ组(P<0.01)。由此可见,饲粮添加1.50%鱼油与12.50%玉米油的混合油脂,即饲粮n-6/n-3 PUFA比值为136.36时,上调了肝脏中FATP基因的表达,增加了肝脏长链脂肪酸的转运及利用效率,促进了冬毛期北极狐的生长。

N-6/N-3多不饱和脂肪酸不同比例对乳腺癌细胞缝隙连接细胞通讯的影响

目的观察n-6／n-3多不饱和脂肪酸（polyunsaturated fatty acid，PUFA）不同比例对乳腺癌细胞缝隙连接细胞通讯的影响。方法n-6／n-3PUFA不同比例（1～10）处理MCF-7（ER^＋）和MDA-MB-231（ER^-）乳腺癌细胞，采用免疫细胞化学观察细胞核Ki-67表达，Western blot检测细胞膜和细胞质缝隙连接蛋白Cx26、Cx43表达，划痕负载染料迁移法分析细胞缝隙连接通讯功能。结果免疫组化结果显示，单纯n-6和10：1n-6／n-3 PUFA增强两种乳腺癌细胞Ki-67表达（P〈0．05），5：1 n-6／n-3 PUFA虽无明显变化，但单纯n-3和1：1n-6／n-3 PUFA抑制细胞Ki-67表达（P〈0．01）。免疫印迹发现，单纯n-3和1：1n-6／n-3 PUFA能明显上调MCF-7细胞膜和细胞质的Cx26、Cx43蛋白表达，单纯n-6 PUFA却下调两种蛋白表达；在MDA-MB-231细胞，n-6／n-3 PUFA不同比例对膜和细胞质的Cx43蛋白表达与MCF-7细胞具有相同趋势，但对Cx26蛋白则无明显作用。用划痕负载染料迁移法却发现，n-6／n-3 PUFA不同比例对细胞缝隙连接通讯功能均无明显影响。结论单纯n-3和1：1n-6／n-3PUFA对MCF-7和MDA-MB-231乳腺癌细胞增殖活性的抑制作用，可能是Cx26和Cx43蛋白通过独立于缝隙连接细胞通讯功能的调节所致。

n-6／n-3多不饱和脂肪酸不同比例对乳腺癌细胞胰岛素样生长因子受体表达的影响

目的探讨n-6／n-3多不饱和脂肪酸（polyunsaturated fatty acid，PUFA）不同比例对乳腺癌细胞株MCF-7（ER^＋）及MDA-MB-231（ER^-）胰岛素样生长因子受体一1（insulin—like growth factor receptor-1，IGF-1R）表达的影响。方法用不同比例的n-6／n．3PUFA（1～10）处理细胞，MTF法检测细胞增殖能力变化；RT—PCR检测细胞IGF-1RmRNA表达变化；Westem blot检测IGF-1R蛋白在细胞膜的表达变化。结果单纯n-6PUFA和10：1n-6／n-3 PUFA能够明显促进MCF-7细胞和MDA—MB-231细胞增殖，诱导细胞IGF-1 RmRNA及蛋白表达上调（P〈0．01）；单纯n-3PUFA和1：1n-6／n-3PUFA则显著抑制细胞增殖，并降低细胞IGF-1RmRNA及蛋白表达水平（P〈0．01）；但5：1n-6／n-3PUFA效果不明显（P〉0．05）。结论不同n-6／n-3PUFA构成能差异性调节乳腺癌细胞IGF-1R表达，其中单纯n-3PUFA和1：1n-6／n-3PUFA能明显降低其表达并抑制乳腺癌细胞增殖。