多不饱和脂肪酸对鱼类免疫与成活的影响及机理

多不饱和脂肪酸(PUFAs)是具有重要生物学功能的独特生物活性物质,是神经和其他细胞膜的重要组分,花生碳四烯酸(AA)和二十碳五烯酸(EPA)还产生类二十烷酸调节机体炎症、T淋巴细胞和B淋巴细胞功能.PUFAs通过影响机体脂类代谢、基因表达、细胞膜功能、机体免疫及血液生化特性等对鱼类生长、发育、免疫和存活发挥重要的作用.本文主要综述PUFAs对鱼类免疫的影响与机理,探讨PUFAs通过提高免疫力而增加鱼类特别是仔稚鱼成活率的调节,以便进一步深入研究PUFAs,更好地利用PUFAs,调控提高鱼类免疫力、生长、发育和成活.     

寄生虫介导的花生四烯酸代谢物免疫调节

宿主感染寄生虫的一个显著表现是在感染期间不能发生有效的免疫反应。花生四烯酸代谢物可能在这一现象中起重要作用。大量的研究证据表明，寄生虫释放花生四烯酸代谢物；寄生虫花生四烯酸代谢物抑制宿主免疫细胞功能，从而有利于寄生虫的入侵和生存；寄生虫也激发宿主细胞产生花生四烯酸代谢物。     

花生四烯酸在畜禽业中的应用

介绍了花生四烯酸的作用机理,综述了其在动物繁殖、生产富含脂肪酸保健蛋等方面的应用,指出了花生四烯酸的开发应用前景。     

花生四烯酸对家禽卵泡颗粒细胞的影响

花生四烯酸是一类顺式多不饱和脂肪酸,是动物细胞膜磷脂的重要组成部分。在家禽生产中,花生四烯酸作为一种必需脂肪酸调控家禽的生长发育;而且作为功能性营养因子,通过在禽蛋中的蓄积来满足人体需求。除了作为前列腺素合成的前体物调节动物生殖过程外,花生四烯酸在调节卵泡颗粒细胞功能的过程中也起重要作用。     

花生四烯酸代谢物在炎症中的作用

综述了花生四烯酸代谢物在炎症过程中的变化和作用以及与其它炎症介质如自由基、肿瘤坏死因子、白介素-1等的相互关系.表明花生四烯酸代谢物在炎症中的作用不是一个孤立的过程,它们与其他炎症介质密切相关,共同参与病理生理发生发展.     

合理使用地塞米松

<正>地塞米松(德沙美松,氟甲强的松龙),是肾上腺糖皮质激素类药物,属甾体类化合物。1药理作用1.1抗炎作用地塞米松能够抑制细胞内磷脂酶,从而抑制细胞膜上的磷脂分解花生四烯酸,花生四烯酸是致炎物质——前列腺素、白三烯、血栓烷等的前体。因此,这类药物抗炎作用的机制之一是能     

花生四烯酸代谢物在炎症中的作用

综述了花四烯酸代谢物在炎症过程中的变化和作用以及与其它炎症介质如自由基、肿瘤坏死因子、白介素－１等的相互关系。表明花生四烯酸代谢物在炎症中的作用不是一个孤立的过程,它们与其他炎症介质密切相关,共同参与病理生理发生发展。     

花生四烯酸在水产动物中的应用

本文就近年来花生四烯酸(20∶4n-6,ARA)对水产动物的营养作用进行综述。     

硒对母牛免疫功能及健康的改善作用研究进展

硒是动物必需的微量元素,其分布与地区有关,一般母牛集中地区硒的含量较少,因而需要在饲料中补充。母牛生产中由于机体免疫机能低下,乳房炎、子宫炎等疾病的发生率较高,严重影响母牛生产的经济效益。日粮中添加适量的硒将会提高母牛免疫功能、改善健康、改善乳品质。目前的研究认为硒对母牛免疫和健康的作用机制主要表现在两方面:一是抗氧化,硒以硒代半胱氨酸参加谷胱甘肽过氧化物酶和硫氧还蛋白还原酶的组成,这2个酶能还原体内产生的过氧化物,从而减少过氧化物对细胞的损伤作用,尤其是对免疫细胞的损伤作用;二是抗炎,硒可通过下调花生四烯酸代谢产生类花生四烯酸的2个限速酶,5-脂氧合酶和白三烯A4水解酶,减少类花生酸类物质如白三烯B4的产生,从而降低其促炎作用。     

如何利用脂肪饲喂肉用仔鸡

<正> 脂肪与其它成分一样是家禽日粮中的重要组成部分。它不仅是家禽可消化能的来源,而且还是不可取代的脂肪酸(亚油酸,亚麻酸,花生四烯酸)的来源。另外。脂肪中还含有抗氧化剂和脂溶性维生素(A、D、E和K)。在配合饲料中添加脂肪的价值还在于它能改善饲料结构,降低含尘量。富含脂肪的混合饲料适口性较强,饲喂效果好。     

The involvement of polymorphonuclear leukocytes in the pathogenesis of bronchopneumonia in calves. VII. Granulocyte activation by arachidonic acid.

Arachidonic acid-induced granulocyte activation was studied in calves. Both in healthy and in bronchopneumonic animals, neutrophil stimulation with 67 microM arachidonic acid caused a rise in granulocyte exocytosis. This event, however, was much more intense in granulocytes from diseased calves. Fatty acids were found to stimulate granule exocytosis from granulocytes. Oleic acid possessed the weakest while dihomo-gamma-linoleic acid showed the strongest activity of this type. It is suggested that arachidonic acid may be an important mediator of calf bronchopneumonia.     

The acute inflammatory process,arachidonic acid metabolism and the mode of action of anti-inflammatory drugs

Arachidonic acid is a polyunsaturated fatty acid covalently bound in esterified form in the cell membranes of most body cells. Following irritation or injury, arachidonic acid is released and oxygenated by enzyme systems leading to the formation of an important group of inflammatory mediators, the eicosanoids. It is now recognised that eicosanoid release is fundamental to the inflammatory process. For example, the prostaglandins and other prostanoids, products of the cyclo-oxygenase enzyme pathway, have potent inflammatory properties and prostaglandin E₂ is readily detectable in equine acute inflammatory exudates. The administration of nonsteroidal anti-inflammatory drugs results in inhibition of prostaglandin synthesis and this explains the mode of action of agents such as phenylbutazone and flunixin. Lipoxygenase enzymes metabolise arachidonic acid to a group of non-cyclised eicosanoids, the leukotrienes, some of which are also important inflammatory mediators. They are probably of particular importance in leucocyte-mediated aspects of chronic inflammation. Currently available non-steroidal antiinflammatory drugs, however, do not inhibit lipoxygenase activity. In the light of recent evidence, the inflammatory process is re-examined and the important emerging roles of both cyclo-oxygenase and lipoxygenase derived eicosanoids are explored. The mode of action of current and future antiinflammatory drugs offered to the equine clinician can be explained by their interference with arachidonic acid metabolism.     

Double blind, placebo-controlled, crossover study of evening primrose oil in the treatment of canine atopy.

Thirty-five dogs with non-seasonal atopic dermatitis were used in a double-blind, placebo-controlled crossover study of the effects of evening primrose (Oenothera biennis) oil. There was a significant treatment effect (P less than 0.05) on erythema. An analysis of the changes in plasma phospholipid levels of essential fatty acids revealed a significant (P less than 0.05) rise in linoleic acid concentration above that in the placebo group. Arachidonic acid levels in the treated group increased significantly (P less than 0.005) in the first phase and also in the second phase (P less than 0.05). In the second phase the levels of arachidonic acid in the active and placebo groups differed significantly (P less than 0.05) and there was a significant treatment effect (P less than 0.05).     

Effects of arachidonic acid and oxytocin on equine endometrial PGF2α during normal cycles and pseudopregnancy

The effect of excess arachidonic acid or oxytocin on equine endometrial prostaglandin F_2α(PGF_2α) synthesis was measured in vitro under physiologic and pathophysiologic conditions. Endometrial tissues obtained by uterine biopsy at 5, 10, 12, 14, 16 and 20 days post-ovulation from cycling mares, after 0, 2, 4, 6, 8, 10, 12, 14 or 16 days of progesterone (P₄) in ovariectomized mares and at 30 days postovulation in mares undergoing spontaneously prolonged corpus luteum (SPCL) activity were incubated in vitro with and without added arachidonic acid or oxytocin. Endometrial PGF_2α content and synthetic capacities were determined by radioimmunoassay. PGF_2α production increased significantly at Days 12–16. Arachidonic acid did not alter this effect. Oxytocin stimulated additional PGF_2α production on Days 5, 16, and 20. SPCL tissues had minimal PGF_2α production which was increased significantly by arachidonic acid but not oxytocin. PGF_2α synthesis in ovariectomized P₄ treated mares was minimal and did not vary with length of progesterone exposure or addition of arachidonic acid. These results suggest that a) oxytocin may play a role in luteolysis in the equine, b) although arachidonic acid appears not to be limiting to PGF₂α production under normal physiological conditions, its absence may play a role in pathophysiological conditions, c) factors in addition to progesterone and arachidonic acid are required to initiate PGF_2α synthesis in the mare.     

The influence of dietary fish oil vs. sunflower oil on the fatty acid composition of plasma cholesteryl-esters in healthy, adult cats

The question addressed was whether the fatty acid composition of plasma cholesteryl esters (CEs) in cats reflects the intake of fatty acids. Diets containing either fish oil or sunflower oil were fed to six healthy, adult cats in a cross-over trial. The dry cat foods contained approximately 18.5% crude fat, of which two-third was in the form of the variable oil. Blood samples were collected at the end of each 4-week feeding period, and the fatty acid composition of plasma CEs and plasma concentrations of lipoproteins were determined. Consumption of the diet with fish oil was associated with significantly greater proportions of eicosapentaenoic acid, arachidonic acid, alpha-linolenic acid, oleic acid, palmitic acid and myristic acid in plasma CEs. The intake of fish oil instead of sunflower oil reduced the percentage of linoleic acid in CEs. The plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, phospholipids and triglycerides were not affected by fish oil vs. sunflower oil feeding.     

Eicosanoids in health and in disease: an appraisal

Oxygenation of the 20-carbon polyunsaturated fatty acid, arachidonic acid, which is found in most body cells of all domestic animals, leads to the formation of a group of compounds possessing biological activity. These compounds, collectively known was eicosanoids, currently receive considerable attention owing to their involvement in a wide variety of physiological and pathophysiological processes. Particular interest has been focussed in recent years on the role and control of prostanoids and leukotrienes in inflammatory and allergic conditions in animals and man. Arachidonic acid metabolites are also recognised to be intimately involved in reproductive and perinatal processes; with platelet aggregation and vascular homeostasis; kidney function; fever; certain tumours and many other normal and disease conditions. Eicosanoid research in veterinary medicine is still at a relatively early stage in many respects and in this review an attempt is given to highlight some of the functions of this important series of compounds both in health and in disease. As more evidence comes to light, it is possible that veterinary surgeons may have to consider revising their clinical approach to the treatment of certain disease states where eicosanoids are implicated or where chemotherapy may interfere with their normal physiological activities.     

Fish meal supplementation increases bovine plasma and luteal tissue omega-3 fatty acid composition

The objective of this experiment was to determine if dietary inclusion of fish meal would increase plasma and luteal tissue concentrations of eicosapentaenoic and docosahexaenoic acids. Seventeen nonlactating Angus cows (2 to 8 yr of age) were housed in individual pens and fed a corn silage-based diet for approximately 60 d. Diets were supplemented with fish meal at 5% DMI (a rich source of eicosapentaenoic acid and docosahexaenoic acid; n = 9 cows) or corn gluten meal at 6% DMI (n = 8 cows). Body weights and jugular blood samples were collected immediately before the initiation of supplementation and every 7 d thereafter for 56 d to monitor plasma n-3 fatty acid composition and BW. Estrous cycles were synchronized using 2 injections of PGF(2α) administered at 14-d intervals. The ovary bearing the corpus luteum was surgically removed at midcycle (between d 10 and 12) after estrus synchronization, which corresponded to approximately d 60 of supplementation. The ovary was transported to the laboratory, and approximately 1.5 g of luteal tissue was stored at -80°C until analyzed for n-3 fatty acid content. Initial and ending BW did not differ (P > 0.10) between cows supplemented with fish meal and those with corn gluten meal. Plasma eicosapentaenoic acid was greater (P < 0.05) beginning at d 7 of supplementation and docosahexaenoic was greater (P < 0.05) beginning at d 14 of supplementation for cows receiving fish meal. Luteal tissue collected from fish meal-supplemented cows had greater (P < 0.05) luteal n-3 fatty acids and reduced (P < 0.05) arachidonic acid and n-6 to n-3 ratio as compared with tissue obtained from cows supplemented with corn gluten meal. Our data show that fish meal supplementation increases luteal n-3 fatty acid content and reduces available arachidonic acid content, the precursor for PGF(2α). The increase in luteal n-3 fatty acids may reduce PGF(2α) intraluteal synthesis after breeding resulting in increased fertility in cattle.     

Parental dietary arachidonic acid altered serum fatty acid profile,hepatic antioxidant capacity,and lipid metabolism in domestic pigeons (Columba livia)

The aim of this study was to explore the effects of dietary arachidonic acid on serum fatty acid profile, hepatic antioxidant capacity, and lipid metabolism in pigeon squabs by supplementing arachidonic acid in their parental diets. A completely randomized design was conducted consisting of control group, 0.05% dietary arachidonic acid supplementation group, 0.1% dietary arachidonic acid supplementation group, and 0.2% dietary arachidonic acid supplementation group. Six randomly selected squabs from each group were sampled on Day 21 post-hatch. Results indicated that moderate level (0.05%) of arachidonic acid in parental diets for pigeon squabs improved lipid metabolism via regulation on serum lipid profile and fatty acid composition and tended to reduce hepatic lipid accumulation in the premise of negligible damage to antioxidant status. Unfortunately, excessive parental supplementation of dietary arachidonic acid might be harmful to squab health. The regulatory effects of arachidonic acid were sensitive to the arachidonic acid doses. In conclusion, parental dietary arachidonic acid at 0.05% could be beneficial for squabs to maintain health as reflective aspects in ameliorative serum lipid profile, fatty acid composition, and reduced hepatic lipid accumulation.     

Dietary (n-3) fatty acids from menhaden fish oil alter plasma fatty acids and leukotriene B synthesis in healthy horses

The study objective was to determine the effect of feeding corn oil or fish oil to horses on plasma fatty acid profiles and leukotriene B (LTB) synthesis by stimulated peripheral blood neutrophils. Two groups of horses (n = 5) were randomly assigned to diets supplemented with either 3.0% (by weight) corn oil or fish oil for a period of 14 weeks. The ratio of (n-6) to (n-3) fatty acids in oil supplements was 68.1:1 for corn oil and 0.12:1 for fish oil. Production of LTB4 and LTB, by peripheral blood neutrophils stimulated with calcium ionophore A23187 and plasma cholesterol, triacylglycerol, and alpha-tocopherol concentrations were measured. At 12 weeks, horses fed fish oil had increased plasma concentrations of eicosapentaenoic acid (27-fold; 8.5 versus 0.3 g/100 g fatty acids; P < .0001), docosahexaenoic acid (34-fold; 5.1 versus 0.1 g/100 g fatty acids; P < .0001), and arachidonic acid (8.3-fold; 4.1 versus 0.5 g/100 g fatty acids; P < .0001) compared with horses fed corn oil. Neutrophils from horses fed fish oil produced 78-fold (P = .01) more LTB5 and 9.5-fold (P = .003) more LTB4 compared with predietary levels, and 17.6-fold (P = .01) and 3.3-fold (P = .02), respectively, more than horses fed corn oil, and the ratio of LTB5 to LTB4 concentrations was 4.0-fold (P = .002) higher in horses fed fish oil. This study suggests that dietary polyunsaturated fatty acids modulate the leukotriene inflammatory response of horses. If the ratio of LTB5 to LTB4 concentrations is important in determining how inflammatory processes are mediated, then fish oil supplementation may have value in treatment of equine inflammatory diseases.     

Whole body cholesterol, fat, and fatty acid concentrations of mice (Mus domesticus) used as a food source.

The concentrations of dry matter, cholesterol, saturated fat, monounsaturated fat, and 29 fatty acids were measured in four size categories of whole mice (Mus domesticus) that are commonly fed to zoo animals. Dry matter increased with age/size of mice, whereas cholesterol decreased with age/size. Significant differences in fatty acid content were found among mice categories with capric, lauric, and myristic acids. Mice categories had similar levels of palmitic, palmitoleic, heptadecenoic, stearic, oleic, linoleic, gamma linolenic, alpha linolenic, eicosenoic, eicosadienoic, arachidonic, docosahexaenoic, and lignoceric acids. Analyzed lipid content of mice exceeded domestic carnivorous animal requirements for linoleic and arachidonic acids. The fatty acid levels in mice were high, falling between published values in beef and fish. Generally, mice contained higher levels of polyunsaturated fatty acids, including the omega-3 fatty acids, and lower levels of saturated fatty acids than beef. Although fatty acid levels met or exceeded some dietary requirements for carnivores and omnivores, a possibility of excessive levels exists that could lead to eye and tissue abnormalities. Furthermore, as the intake of dietary polyunsaturated fatty acids increases, the dietary requirement for vitamin E increases. Thus, it is important that lipid profiles of feeder mice be known and considered when examining captive animal diets.