绿色巴夫藻在UV-B胁迫后的生长补偿效应

以绿色巴夫藻(Pavlova viridis)为试验材料,设置了4、6、8、10μW.cm-2和12μW.cm-25个UV-B辐射强度,以无紫外辐射为对照,UV-B分别胁迫处理10min(a组)和15min(b组)。解除胁迫后,处理组和对照组在相同接种密度和相同条件下培养12d,测定了生长过程中的吸光值、色素含量、可溶性蛋白质和胞内多糖含量。结果表明,P.viridis在UV-B胁迫下,藻细胞生长受到显著抑制,a组和b组辐射处理的细胞相对增长率分别比对照下降了17.70%~51.54%和26.16%~60.01%(p<0.05)。但是,当胁迫解除后,各处理的藻细胞生长速率,在恢复阶段前期(1~4d)与对照无显著差异,在恢复阶段的中后期(6~12d)则显著(p<0.05)或极显著(p<0.01)高于对照。证明P.viridis在胁迫后的恢复生长中表现超补偿生长现象,恢复培养第12d的最大光密度值比对照提高了26.55%,最大叶绿素a、类胡萝卜素、可溶性蛋白质和胞内多糖含量分别比对照提高了29.17%、29.93%、15.34%和34.37%。当然,在各处理中,随着辐射时间的延长和辐射强度的增大,超补偿生长发生的时间也相对滞后。     

不同脂肪源对泥鳅稚鱼生长性能及脂肪酸组成的影响

为研究饲料不同脂肪源对泥鳅稚鱼生长性能及鱼体脂肪酸组成的影响, 实验选择初始体重为(10.002.00) mg的健康泥鳅稚鱼1500尾, 随机分为5组, 每组3个重复, 每个水箱100尾鱼, 分别投喂5种含有鱼油(FO)、大豆油(SO)、玉米油(CO)、花生油(PeO)和棕榈油(PaO)的配合饲料, 每种饲料3个重复, 饲养期为40d。结果显示, 摄食不同脂肪源饲料的泥鳅稚鱼在增重率、成活率、饲料系数等生长性能指标和体成分上没有显著差异(P0.05), 但是, 摄食FO组鱼体极性脂肪含量显著高于其他植物油组(P0.05)。鱼油组鱼体中性和极性脂肪中总n-3系脂肪酸含量和EPA+DHA含量显著高于其他植物油组(P0.05)。植物油组鱼体极性脂肪中20:4n-6含量显著高于鱼油组(P0.05), 表明泥鳅稚鱼具有将C18转换为C20的能力。研究表明, 在饲料中添加足量磷脂, 鱼油、大豆油、玉米油、花生油、棕榈油都可以用作泥鳅稚鱼期专用饲料脂肪源。     

邻苯二甲酸二丁酯对绿色巴夫藻的生长毒性和干扰效应

采用批次培养的方法研究了邻苯二甲酸二丁酯(DBP)对绿色巴夫藻(Pavlova viridis)的生长毒性和干扰效应。实验设置了0 mg·L^-1、2.5 mg·L^-1、3.0 mg·L^-1、3.5 mg·L^-1、4.0 mg·L^-1、5.0 mg·L^-1和7.5 mg·L^-1 共7个质量浓度梯度的DBP暴露处理组,测定了绿色巴夫藻的细胞密度、光合色素含量、叶绿素荧光特性及丙二醛(MDA)含量等指标,试图揭示DBP对绿色巴夫藻的生态毒性影响规律及机制。结果表明:DBP暴露对绿色巴夫藻的生长具有显著抑制作用,高质量浓度(5.0 mg·L^-1和7.5 mg·L^-1)DBP暴露下绿色巴夫藻细胞10 d内全部死亡;随着DBP暴露质量浓度增加,藻细胞叶绿素a和类胡萝卜素含量均显著降低;DBP暴露使光系统Ⅱ(PSⅡ)的最大光能转化效率(F_v/F_m)、潜在光化学活性(F_v/F_o)、实际光能转化效率(Yield)和光合电子传递速率(ETR)等指标也显著降低;DBP暴露还能够使绿色巴夫藻的细胞MDA含量显著增加。该研究进一步证实了DBP污染物对微藻光系统和酶类生理生化过程的干扰作用。     

不同质量浓度NaNO3对3种微藻生长及总脂肪酸含量和组成的影响

以BG11为基本培养液,研究了不同质量浓度NaNO3(37.5～1 875.0 mg·L-1)对微藻P9(Klebsormidium sp. )、TH6(Oedocladium sp. )和CF5(Stigonema sp. )生长及总脂肪酸含量和组成的影响.结果显示,调整(减少或增加)培养液中NaNO3的质量浓度,对3种微藻的生长量及总脂肪酸含量和脂肪酸组成均有一定的影响;NaNO3的质量浓度较低(37.5或75.0 mg·L-1),3种微藻的鲜质量随培养时间的延长呈先逐渐增加然后略有降低的趋势;而在NaNO3质量浓度为150.0～1 875.0 mg·L-1的条件下,在一定的培养时间(18～33 d)内,3种微藻的鲜质量均逐渐增加;总体上看,3种微藻的生长量随NaNO3质量浓度的提高呈现逐渐增加的趋势,但仅在含1 875.0 mg·L-1 NaNO3的培养液中3种微藻的生长量高于对照(1 500.0 mg·L-1NaNO3).在含375.0 mg·L-1NaNO3的培养液中培养33 d,微藻 P9的总脂肪酸含量最高(25.39%),是对照的 1.79 倍,软脂酸、亚油酸、油酸和硬脂酸的相对含量分别是对照的2.50、2.72、2.24和2.08倍;在含37.5 mg·L-1 NaNO3的培养液中培养33 d,微藻TH6的总脂肪酸含量最高(20.69%),是对照的 1.89倍,软脂酸、亚油酸和油酸的相对含量分别是对照的3.37、1.79和1.92倍;不同处理组间微藻CF5的总脂肪酸含量及组成有一定差异,但随着NaNO3质量浓度的提高变化趋势不明显.研究结果表明,适当提高培养液中的NaNO3浓度对微藻的生长有一定的促进作用,不同种类微藻适宜的NaNO3浓度有一定的差异.综合考虑生长量和总脂肪酸含量及脂肪酸组成等因素,确定适宜于微藻P9、TH6和CF5培养的NaNO3质量浓度分别为375.0、37.5和150.0 mg·L-1.     

绿色巴夫藻脂肪酸去饱和酶的克隆和初步研究

在高等植物中,Δ9 脂肪酸去饱和酶引入第一个双键到饱和的脂肪酸链中,导致单不饱和脂肪酸的形成。我们通过RT-PCR、RNA ligase mediated RACE (RLM-RACE) and Overlap-PCR方法从海洋微藻绿色巴夫藻中克隆到一个命名为PvfadA的脂肪酸去饱和酶候选基因。通过将PvfadA基因在大肠杆菌表达系统中成功表达,PvFadA可以特异性地将C18:0脂肪酸转变成C18:1脂肪酸。PvFadA的氨基酸序列中存在一个存在于acyl-ACP去饱和酶的特异性金属离子结合区段(D/E)X2HX-100(D/E)X2H。通过同源模建PvFadA的3D结构显示,其包含了11个α螺旋,其中α3、α4、α6和α7组成了一个4个螺旋桶的核心结构,预测其可能是酶的活性中心。PvFadA的3D结构类似于蓖麻和结核分枝杆菌H37Rv的acyl-ACP去饱和酶。     

不同脂肪源对异育银鲫的生长、体组成和肌肉脂肪酸的影响

配制了十种等氮等能的饲料饲喂3.53 g的异育银鲫幼鱼12周, 探讨异育银鲫对不同脂肪源的利用效果。十种饲料中分别添加8%的鱼油(FO)、椰子油(CNO)、玉米油(CO)、亚麻油(LO)、大豆油(SO)、菜籽油(RO)、1∶1鱼油-椰子油(FCNO)、1∶1鱼油-玉米油(FCO)、1∶1鱼油-亚麻油(FLO)和1∶1∶1∶1鱼油-椰子油-玉米油-亚麻油混合油(MIX)。每组饲料三个平行, 每个平行30尾。实验在循环水养殖系统中进行, 水温控制在(241)℃。结果表明, 在单一脂肪源中, 豆油组和椰子油组的增重率最高, 其次是菜籽油组, 鱼油、玉米油和亚麻油组的增重率最低。与相应的单一脂肪源相比, 饲料中鱼油与椰子油、玉米油或亚麻油1∶1混合后使用提高了异育银鲫的生长。摄食不同脂肪源饲料的异育银鲫血清生化指标、各组织的水分和脂肪含量差异不明显(P0.05)。肌肉脂肪酸与饲料脂肪源呈明显正相关。摄食豆油和菜籽油饲料的鱼体肌肉中20:4n-6较高, 而摄食亚麻油饲料的鱼则含有较高的20:5n-3和22:6n-3, 表明异育银鲫具有转化18:2n-6和 18:3n-3为高不饱和脂肪酸的能力。从实验可以看出, 豆油、椰子油和菜籽油是异育银鲫饲料中良好的脂肪源。       

不同饵料对卤虫生长、总脂含量及脂肪酸组成的影响

为了提高养殖卤虫的饵料营养价值,了解其不同生长阶段营养成分变化情况,采用单因子试验研究了8种饵料（三角褐指藻、小球藻、微绿球藻、酵母液、三角褐指藻＋小球藻＋微绿球藻、三角褐指藻＋酵母液、小球藻＋酵母液和微绿球藻＋酵母液）对卤虫生长、总脂含量及脂肪酸组成的影响,结果表明：不同饵料种类对卤虫生长、总脂含量及脂肪酸组成的影响显著（P＜0.05）,增长率,以三角褐指藻＋酵母液最优;总脂含量、以三角褐指藻最优（19.67%）,除酵母液外,与其它饵料相差不显著（P＞0.05）;脂肪酸组成效果,以微绿球藻组最优（EPA：18.01%,DNA：0.55%,（n-3）HUFA：19.08%）,与三角褐指藻组相差不大（P＞0.05）,显著高于其它各组（P＞0.05）.同时以三角褐指藻为饵料,研究了卤虫不同生长阶段（体长2、4、6、8、10 mm）总脂含量、脂肪酸组成变化,结果表明：卤虫体长2～10 mm总脂含量为14.27%～20.93%,随体长的增长降低;EPA、DHA及（n-3）HUFA的含量,均随体长的增长降低,EPA含量为：10.47%～20.77%,DNA含量为：0～0.70%,（n-3）HUFA含量为：10.85%～22.01%.结论认为,卤虫以三角褐指藻或三角褐指藻＋酵母液为饵料培养营养价值最佳,其体长小于6 mm营养价值较佳.     

适于松茸生长的生态条件

松茸 [Ｔｒｉｃｈｏｌｏｍａｍａｔｓｕｔａｋｅ (Ｓ .Ｉｔｏ.ｅｔＩ ｍａｉ.)Ｓｉｎｇ .],因生长在松林地 ,菌蕾状如鹿茸而得名。因其大多数种具有较高的商品价值 ,外形酷似而难以区别 ,故民间均以松茸称谓。松茸为商品名称 ,别名松口蘑、杉蕈、松菇 ,在现代真菌分类系统中隶属担子菌门 (Ｂａｓｉｄｉｏｍｙｃｏｔａ)、担子菌纲(Ｂａｓｉｃｉｏｍｙｃｅｔｅｓ) ,蘑菇目 (Ａｇａｒｉｃａｌｅｓ)、口蘑科(Ｔｒｉｃｈｏｌｏｍａｔａｃｅａｅ)、白蘑属 (Ｔｒｉｃｈｏｌｏｍａ) ,白蘑亚属 (Ｓｕｂｙ .Ｔｒｉｃｈｏｌｏｍａｓｉｎｇ .)、原发组 […     

饲料脂肪水平对杂交鲟幼鱼生长、饲料消化率、抗氧化水平和肌肉脂肪酸组成的影响

研究旨在探究饲料中不同脂肪水平对西伯利亚杂交鲟(Acipenser baerii Brandt♀×A. schrenckii Brandt♂)幼鱼生长、饲料消化率、血清生化指标及肌肉脂肪酸组成的影响。以鱼油为脂肪源,配制4种脂肪水平分别为5%(D05)、10%(D10)、15%(D15)和20%(D20)的等氮饲料。选用初始体重为(152.83±0.67) g的杂交鲟,随机分为4组,每组3个重复,每个重复25尾鱼。养殖周期为12周。结果显示,饲料中不同脂肪水平对杂交鲟的生长性能有显著影响(P<0.05)。其中, D15组杂交鲟幼鱼的末均重(FBW)、增重率(WGR)和特定生长率(SGR)显著高于D05、D10和D20组(P<0.05),饲料效率(FE)显著高于D05和D10组(P<0.05)。随着饲料中脂肪含量的增加,杂交鲟幼鱼脏体比(VSI)、肝体比(HSI)及肌肉、肝脏中的脂肪含量显著上升(P<0.05)。饲料中不同脂肪水平对干物质(ADCd)、蛋白质(ADCp)表观消化率无显著影响(P>0.05)。D10、D15和D20组脂肪表观消化率(ADCf)显...     

温度、光照和盐度对2株曼氏骨条藻生长及脂肪酸组成的影响

研究温度、光照、盐度对2株曼氏骨条藻（Skeletonema munzelii）SM-1、SM-2生长、总脂含量及脂肪酸组成的影响,以确定其生长及油脂、多不饱和脂肪酸积累的最适生态条件。在实验室智能光照培养箱内不充气培养控制条件下,采用单因子试验分别研究了不同温度（10、15、20、25和30℃）、光照强度（20、40、60、80、100和120μmol/m2·s）、盐度（10、15、20、25、30、35和40）对2株藻的生长、总脂含量及脂肪酸组成的影响。结果表明：不同温度、光照强度及盐度对2株藻的生长、总脂及脂肪酸含量影响均有显著影响（P〈0.05）。藻株SM-1生长的最适温度为25℃,最适光强60μmol/m2·s,最适盐度30,而低温（10~15℃）,低光照（20μmol/m2·s）,低盐度（盐度15）更有利于总脂及PUFA的积累。SM-2生长的最适温度为20℃,最适光强60μmol/m2·s,最适盐度30,而低温（10~15℃）,低光照（20μmol/m2·s）更有利于其总脂及PUFA的积累,低盐（盐度15）则更有利于PUFA的积累。因此在实际生产中,2株藻可先在最适条件下培养以增加生物量,后转至利于PUFA积累的条件下提高PUFA产量。     

培养条件对青枯雷尔氏菌脂肪酸组成的影响

应用气相色谱技术测定不同温度、培养时间、pH值等培养条件下青枯雷尔氏菌(Ralstonia solanacearum)脂肪酸的结果表明: 青枯雷尔氏菌强致病力菌株Rs-J.1.4-010704-01v的脂肪酸种类有14~34种, 主要特征脂肪酸为C16:1ω7c/C15:0 ISO 2OH(10.644 min), C16:0(10.950 min), C18:1ω7c(14.177 min), 所占总百分比含量为总脂肪酸的55.66%~75.69%; 该菌脂肪酸的种类与含量随着培养条件的改变而发生变化,     

不同类型脂肪酸对SD大鼠血清脂肪酸及胰岛素抵抗的影响

目的分析中链饱和脂肪酸（MC-SFA,MCF组）、长链饱和脂肪酸（LC-SFA,LCF组）、n-6多不饱和脂肪酸（n-6 PUFA,SUF组）和n-3多不饱和脂肪酸（n-3 PUFA,TUF组）四种脂肪酸对大鼠血清脂肪酸及胰岛素抵抗的影响。方法雄性SD大鼠40只随机分为5组,对照组给予普通日粮,高脂组给予脂肪热量比相同的高脂日粮。喂养10周,每18 d测定空腹血糖（GLU）、血清脂肪酸、血清胰岛素水平,根据胰岛素敏感性指数（ISI）=ln1/（FPG×FINS）评定大鼠的胰岛素敏感性。结果10周后,LCF组和SUF组大鼠体重显著高于对照组和其它高脂组;LCF组血清胰岛素显著高于对照组（P﹤0.05）;LCF组、TUF组ISI显著低于对照组（P﹤0.05）;各组间血糖无明显差异（P〉0.05）。SUF组、TUF组血清LC-SFA浓度显著低于LCF组（P﹤0.05）;TUF组血清（n-3 PUFA）显著高于对照组和其它高脂组（P﹤0.05）。结论不同类型脂肪酸的高脂饲料对SD大鼠的血清脂肪酸组成和含量有显著的影响,SD大鼠脂肪沉积及胰岛素抵抗程度随血清脂肪酸代谢作用的不同而变化。     

Fatty Acid Composition of Baobab Seed and Its Relationship with the Genus Adansonia Taxonomy

Baobab seed oil contains specific fatty acids. Most of the studies on baobab fatty acids have been carried out singly and in isolation from each other, making it difficult to compare results through different species. The objective of the present study is to establish the seed fatty acid composition of each Adansonia species in order to evaluate and understand the relationships between the oil chemical compositions, the baobabs’ taxonomy and, the ecological and geographical origin of each seed lot. The seed oils have been analysed using gas chromatography (GC). The oils of all baobab species contain three major fatty acids: palmitic, oleic and linoleic acids. They also contain specific fatty acids such as cyclopropenic and cyclopropanic acids, which are characteristic of the Malvaceae family seed oils. It was possible to distinguish three sections through principal components analysis using the eleven fatty acids identified by GC. The Adansonia section contains high rates of oleic acid (± 35%), the Brevitubae section is rich in palmitic acid (± 42%) and the Longitubae section contains high levels of dihydrosterulic acid (± 5%). The oil fatty acid composition, however, does not enable a definitive characterization of profiles according to species. The fatty acid composition is not significantly influenced by the geographical, soil and climate conditions of the collection sites.     

Influences of Culture Temperature on the Growth, Lipid Content and Fatty Acid Composition of Aurantiochytrium sp. Strain mh0186

The growth, lipid content, and fatty acid composition of Aurantiochytrium sp. strain mh0186 at different temperatures were investigated. Strain mh0186 grew well at 15–30°C, but weakly at 10°C. The biomass at 15–30°C was significantly higher than at 10 and 35°C, and the total lipid at 15–35°C was significantly higher than that at 10°C. The amount of DHA in the total fatty acid was highest at 10°C and decreased in response to temperature increase. The content of DHA (mg/g-dry cell weight) at 15–30°C were significantly higher than those at 35°C and those at 15–25°C were significantly higher than those at 10 and 35°C. The DHA yield at 15–35°C was significantly higher than those at 10 and 35°C. Unsaturation of fatty acid was regulated by temperature and was enhanced in response to temperature decrease. The ratio of DHA to DPA varied at different temperatures.     

Effect of Dietary Mono- and Polyunsaturated Fatty Acids on the Fatty Acid Composition of Pigs' Adipose Tissues

In two experiments with growing-finishing pigs six different dietary fats were added to a conventional diet (control - C) to study the effects of dietary monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) on the fatty acid composition of backfat and kidney fat at similar amounts of double bonds in feed (Exp. 1:7% pork fat - PF, 4.95% olive oil - OO, 3.17% soybean oil - SO) or a constant amount of 5% of processed fats (Exp. 2: partially hydrogenated fat - SAT, fractionated pork fats: olein - OLE, stearin - STE). Compared with the control, PUFA were only slightly increased in backfat of pigs fed PF, OLE, STE or OO, although dietary PUFA intake was up to 70% higher. With SO PUFA were significantly increased in adipose tissues, predominantly at the expense of MUFA. Consequently, a non-linear relationship was found between PUFA intake and proportion in backfat. MUFA were incorporated at the expense of SFA, therefore, adipose tissues of OO fed animals were lowest in SFA. Despite comparable amounts of double bonds in feed (Exp. 1), the degree of unsaturation measured as fat score (sum of double bonds) was in the order SO > OO > PF > C. In contrast, the proportion of SFA was C > PF = SO > OO. Regarding the decisive role of SFA for fat consistency it may be concluded that MUFA should also be considered in feeding recommendations for pigs. Furthermore, in case of a high dietary supply of MUFA, a simple index of double bonds might not be sufficiently conclusive to judge pig fat quality.     

Influence of Host Diet on the Fatty Acid Composition and Content of Rumen Protozoa in Cattle

The fatty acid profiles and contents of protozoa from the rumen fluid of cattle varied according to the type of diet consumed by their host. Changing from a high-quality hay diet to a low-quality hay diet (DA) decreased the proportions of saturated acids and increased the proportions of the unsaturated acids 18:1 cis-9, 18:2 and 18:3 in neutral lipids (NL) and phospholipids (PL). Adding sucrose, urea and sulphur (SUS) to DA increased the proportions of branched chain acids in PL while addition of safflower oil increased polyunsaturated acids in PL and 18:1 trans-11 in NL. Diet did not alter the PL fatty acid content of protozoa but oil supplement of DA resulted in a 10-fold increase in the content of free fatty acids. The defaunating effect of oil supplement was partly reversed by SUS suggesting that factors other than the fatty acid content of cells are important in determining the toxicity of oil to rumen protozoa. The results indicate that the amounts of individual long-chain fatty acids taken up by rumen ciliates are largely determined by their concentrations in rumen digesta.     

我国健康成人红细胞膜脂类的脂酸组成

 本文采用双向簿层层析分离红细胞膜脂类,继以毛细管气相色谱法分析其脂酸含量,检测了15名我国健康成人红细胞膜脂类的脂酸摩尔百分组成。结果表明:各脂类中,脂酸的类别基本相同,但其含量组成相差甚远。如磷脂酰乙醇胺(PE)富含C_(20:4);磷脂酰胆碱(PC)富含C_(18:2);神经鞘磷脂(SM)主要含C_(16:0);磷脂酰丝氨酸(PS)主要含C_(18:0);而以红细胞糖苷脂(GL)中脂酸含量最少。膜总脂中饱和脂酸与不饱和脂酸的含量大致相等,胆碱磷脂(PC+SM)的脂酸饱和度则明显高于氨基磷脂(PE+PS)。     

Lipid and Fatty Acid Composition of Brain Tissue from Adrenoleukodystrophy Patients

Abstract: White matter and active plaque tissue from adrenoleukodystrophy (ALD) patients were analysed for lipid class and fatty acid compositions and the results compared with white matter from normal brain. ALD white matter was characterized by increased levels of cholesteryl esters and decreased levels of phosphatidylethanola- mine, including phosphatidylethanolamine plasmalogen, in comparison with normal brain white matter. In addition to even higher levels of cholesteryl esters, ALD plaque tissue had reduced levels of cerebrosides as well as phosphati-dylethanolamines. The loss of phosphatidylethanolamine plasmalogen is indicative of early demyelination. Total lipid from ALD white matter and ALD plaque tissue contained nearly five times and seven times, respectively, more 26:0 than total lipid from normal brain white matter. The 26:0 in ALD white matter was elevated in all lipid classes except phosphatidylinositol, but was located mainly in cerebrosides, phosphatidylcholine, sphingomyelin, and sulfatides. Most of the 26:0 in ALD plaque tissue was present in cholesteryl esters, followed by phosphatidylcholine and sphingomyelin, with reduced amounts in cerebrosides as compared with ALD white matter. The results are consistent with an initial accumulation of very-long-chain fatty acids in ALD white matter, primarily in sphingolipids and phosphatidylcholine, and subsequent accumulation of very-long- chain fatty acids in cholesteryl esters during demyelination. In addition, it was notable that the sphingolipids, especially sphingomyelin in ALD brain, had decreased levels of 24:1 and increased levels of 18:0, as well as increased levels of very-long-chain fatty acids. The extent to which the data shed light on mechanisms of demyelination in ALD is discussed.     

Intrauterine Growth Retardation (Malnutrition by Vascular Ligation) Induces Modifications in Fatty Acid Composition of Neurons and Oligodendrocytes

Intrauterine growth retardation (IUGR) induced by ligation of one uterine artery on day 17 of pregnancy in the rat lead to major abnormalities in the fatty acid content of neurons and oligodendrocytes but not in astrocytes. In neurons from IUGR rats, monounsaturated fatty acids were decreased; in the polyunsaturated series, ω-3 fatty acids were increased and Ω-6 fatty acids were decreased. In oligodendrocytes, monounsaturated fatty acids were also decreased, but the modifications in polyunsaturated fatty acids were the opposite of those in neurons: Ω-3 being decreased and w-6 increased. Although the animals received a normal diet after birth, the alterations were still present in adulthood. In addition, fatty acid composition of brain cells is a very indicative criterion of brain maturation.     

Fatty Acid Composition of Endoneurium and Perineurium from Adult Rat Sciatic Nerve

Reports on lipid composition of peripheral nervous system have generally been restricted to the saturated fatty acids of the endoneurium. In this work we attempt to determine the fatty acid composition of the different lipid classes in both endo- and perineurium from sciatic nerve microdissection on adult rats. Unsaturated fatty acids were found to make up around 60% of total fatty acids in samples of endoneurium and perineurium, with monounsaturated fatty acids forming 40-50% of total unsaturated fatty acid content. Although the same fatty acids were present in both tissues there was a striking difference in C 18:1 (n-9) and C 18:2 (n-6) ratio between endoneurium and perineurium, which is particularly rich in linoleic acid. The nonpolar perineurial lipids were found to be richest in linoleic acid. Phospholipids were present in the perineurium, and they contained high proportions of saturated and medium-chain monounsaturated fatty acids.