The effect of selenium and vitamin E on microvascular permeability of rat organs

The effects of dietary sodium selenite and vitamin E on the microvascular permeability of rat organs such as heart, brain, kidney, liver and eye were investigated by using the Evans blue leakage method. Combined deficiency of selenium and vitamin E caused an increase in the permeability of the heart and eye with respect to their controls while it had no considerable effect on the permeability of other organs. On the other hand, toxic levels of selenium (4.2 mg/kg) in diet decreased the permeabilities in kidney, liver, and eye whereas this parameter of brain increased in the same animal group. These results suggested that low or high sodium selenite and vitamin E contents in diet could alter the microvascular permeability of different organs in different manners. It might be important to give reasonable explanations for the pathophysiology of some diseases that are characterized with organ damage and /or disfunction originated from selenium deficiency or toxicity.     

Protective role of intraperitoneally administered vitamin E and selenium on the antioxidative defense mechanisms in rats with diabetes induced by streptozotocin

The aim of this work was to determine the protective effects of intraperitoneally administered vitamin E and selenium (as Na₂SeO₃, Se) on the lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and vitamin E levels, glutathione peroxidase (GSH-Px), reduced glutathione (GSH) activities in the plasma, red blood cell (RBC), liver, and muscle of rats with streptozotocin-induced diabetes. Fifty adult male Wistar rats were used and all rats were randomly divided into five groups. The first group was used as a control and the second group as a diabetic control. A placebo was given to first and second groups by injection. The third group was intraperitoneally administered with vitamin E (20 mg over 24 h), the fourth group with Se (0.3 mg over 24 h), and the fifth group with vitamin E and Se combination (COM) (20 mg vitamin E + 0.3 mg Se over 24 h). This administration was done for 25 days and the TBARS, vitamin E, GSH-Px, GSH levels in the plasma, RBC, liver, and muscle samples were determined. The vitamin E level in the plasma and liver was significantly (p < 0.05) higher in the control than in the diabetic control group. Also, the TBARS levels in the RBC, liver, and muscle were significantly (p < 0.05) lower in the control than in the diabetic control group. However, GSH-Px and GSH activities in RBC, liver, and muscle were not statistically different between the control and the diabetic control groups. The vitamin E levels in plasma and liver (p < 0.01 and p < 0.001) and GSH-Px activities (p < 0.01, p < 0.001) in RBC were significantly higher in vitamin E, Se, and COM groups than in both control and diabetic control groups. However, the TBARS levels of RBC, muscle, and liver in vitamin E and Se administered groups were significantly (p < 0.05-p < 0.001, respectively) decreased. These results indicate that intraperitoneally administered vitamin E and Se have significant protective effects on the blood, liver, and muscle against oxidative damage of diabetes. The abstract of this study was presented in Physiological Research 48(Suppl. 1), S99 (1999).     

Effect of selenium and vitamin E supplementation on lipid abnormalities in plasma, aorta, and adipose tissue of Zucker rats

Twenty-nine obese female Zucker rats (fa / fa) were fed with a laboratory chow supplemented or not with a selenium-rich yeast (Selenion), or Selenion + vitamin E, or vitamin E alone. Twelve lean female Zucker rats (Fa / Fa) of the same littermates fed with the same diet were used as control. After 32 wk of diet, obesity induced a large increase in plasma insulin and lipid levels. A significant decrease in the plasma vitamin E/triglycerides ratio (p < 0.005) and an increase in plasma thiobarbituric reactive substances (TBARS) (p < 0.005) were also observed. Plasma selenium and vitamin E increased in all supplemented rats. The plasma insulin level was decreased by selenion supplementation and the vitamin E/triglycerides ratio was completely corrected by double supplementation with Selenion + vitamin E. TBARS were also efficiently decreased in two obese groups receiving vitamin E. In plasma, adipose tissue and aorta, obesity induced an increase in palmitic acid (C16:0), a very large increase in monounsaturated fatty acids (palmitoleic acid C16:l, stearic acid C18:l) associated with a decrease in polyunsaturated n-6 fatty acids (linoleic acid C18:2 n - 6, arachidonic C20:4 n - 6). These alterations in fatty acid distribution were only partly modulated by Se and vitamin E supplements. However, in the aorta, antioxidant treatment in obese rats significantly reduced the increase in C16:0 and C16:l (p < 0.05 andp < 0.01, respectively) and the decrease in arachidonic acid (p < 0.05). These changes could be beneficial in the reduction of insulin resistance and help to protect the vascular endothelium.     

In vitro and in vivo effects of selenium and selenium with vitamin E on platelet functions in diabetic rats relationship to platelet sorbitol and fatty acid distribution

In vitro 30 min of incubation with selenomethionine (Sm)+vitamin E multiplied by about five platelet selenium (Se) decreased significantly platelet thrombin and ADP-induced aggregation decrease. Four groups of streptozotocin-induced diabetic rats were fed with a supplemented purified diet with an Se-rich yeast (Selenion): DSel, Sm: DSm, Sm α-tocopherol: DSmE or unsupplemented diet: D. After 24 wk of supplementation, only a decrease in thrombin-induced aggregation in group DSel compared to DSm and DSmE and D was observed. However, after 24 wk of diet compared to 14 wk, in group D and DSm, a significant increase in thrombin-induced aggregation occurred (p<0.0001), whereas a significant decrease in groups DSel and DSmE (p<0.0001,p<0.03) was noted. After 21 wk of diet, in DSmE, platelet adhesion to fibronectin was significantly decreased compared to group D (p<0.05). These changes in DSmE were associated with a significant decrease in platelet sorbitol (p<0.02) and a very significant increase in platelet Se (p<0.0005). Sm associated with vitamin E would appear more efficient to prevent oxidative damage of diabetic platelet membrane and thus to modulate its hyperactivity.     

Effects of dietary vitamin E and selenium on antioxidative defense mechanisms in the liver of rats treated with high doses of glucocorticoid

The aim of this work was to determine the effects of dietary intake vitamin E and selenium (Se) on lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and on the antioxidative defense mechanisms in the liver of rats treated with high doses of prednisolone. Two hundred fifty adult male Wistar rats were randomly divided into five groups. The rats were fed a normal diet, but groups 3, 4, and 5 received a daily supplement in their drinking water of 20 mg vitamin E, 0.3 mg Se, and a combination of vitamin E and Se, respectively, for 30 d. For 3 d subsequently, the control group (group 1) was treated with a placebo, and the remaining four groups were injected intramuscularly with 100 mg/kg body weight (BW) prednisolone. After the last administration of prednisolone, 10 rats from each group were killed at 4, 8, 12, 24, and 48 h and the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) enzymes and the levels of glutathione (GSH) and TBARS in their livers were measured. GSH-Px, SOD, and CAT enzyme activities and GSH levels in prednisolone-treatment group (group 2) began to decrease gradually at 4 h, falling respectively to 38%, 55%, and 40% of the control levels by 24 h, and recovering to the control levels at 48 h. In contrast, prednisolone administration caused an increase in the hepatic TBARS, reaching up to four times the levels of the control at 24 h. However, supplementation with vitamin E and Se had a preventive effect on the elevation of the hepatic TBARS and improved the diminished activities of the antioxidative enzymes and the levels of GSH. Therefore, the present study demonstrates the effectiveness of vitamin E and Se in reducing hepatic damage in glucocorticoid-treated rats and suggests that reductions in increased TBARS as a result of prednisolone may be an important factor in the action of vitamin E and Se.     

Effects of dietary selenium and vitamin E concentrations on phospholipid hydroperoxide glutathione peroxidase expression in reproductive tissues of pubertal maturing male rats

Phospholipid hydroperoxide glutathione peroxidase (PHGPX) is the second intracellular selenium (Se)-dependent glutathione peroxidase (GSH-Px) identified in mammals. Our objectives were to determine the effect of dietary vitamin E and Se levels on PHGPX activity expression in testis, epididymis, and seminal vesicles of pubertal maturing rats, and the relationship of PHGPX expression with testicular development and sperm quality. Forty Sprague-Dawley male weanling rats (21-d old), were initially fed for 3 wk a torula yeast basal diet (containing 0.05 mg Se/kg) supplemented with marginal levels of Se (0.1 mg/kg as Na₂SeO₃) and vitamin E (25 IU/kg as all-rac-α-tocopheryl acetate). Then, rats were fed the basal diets supplemented with 0 or 0.2 mg Se/kg and 0 or 100 IU vitamin E/kg diet during the 3-wk period of pubertal maturing. Compared with the Se-supplemented rats, those fed the Se-deficient diets retained 31, 88, 67, and 50% of Se-dependent GSH-Px activities in liver, testis, epididymis, and seminal vesicles, respectively. Testes and seminal vesicles had substantially higher (5-to 20-fold) PHGPX activity than liver. Dietary Se deficiency did not affect PHGPX activities in the reproductive tissues, but reduced PHGPX activity in liver by 28% (P < 0.0001). Dietary vitamin E supplementation did not affect PHGPX activity in liver, whereas it raised PHGPX activity in seminal vesicles by 43% (P < 0.005). Neither dietary vitamin E nor Se levels affected body weight gains, reproductive organ weights, or sperm counts and morphology. In conclusion, expression of PHGPX activity in testis and seminal vesicles was high and regulated by dietary Se and vitamin E differently from that in liver.     

Protective role of intraperitoneally administered vitamins C and E and selenium on the levels of lipid peroxidation in the lens of rats made diabetic with streptozotocin

The aim of this work was to determine the protective effects of intraperitoneally administered vitamins C and E and selenium on the lipid peroxidation (MDA), glutathione peroxidase (GSH-Px), reduced glutathione (rGSH) activities in the lens of rats induced diabetic with streptozotocin (STZ). Lenses in the diabetic control group had a slightly higher mean level of MDA compared with lenses of the vitamin E and selenium groups, although the mean levels of MDA were significantly lower in control, combination, and vitamin C groups than in the diabetic control group (p < 0.05 andp < 0.01). However, MDA levels were significantly lower in vitamin C, vitamin E, and combination groups than in controls (p < 0.01). The GSH-Px activities of lenses were significantly higher in vitamin C-, vitamin E- and selenium-injected groups than that in the diabetic control group (p < 0.01), whereas, the activity of GSH-Px was significantly lower in the diabetic control group than in the control group. In addition, the rGSH content was seen to decrease only in the vitamin C group compared to both control and diabetic control groups (p < 0.05). In conclusion, the results from these experiments indicate that vitamins C and E and selenium can protect the lens against oxidative damage, but the effect of vitamin C appears to be much greater than that of vitamin E and selenium.     

Protective role of intraperitoneally administered vitamin E and selenium in rats anesthetized with enflurane

The aim of this investigation was to determine levels of liver vitamins A and E and blood biochemical and hematological parameters in the enflurane anesthesia of rats. Fifty adult male Wistar rats were used in this study. All rats were randomly divided into five groups. The first and second groups were used as the control and anesthesia control groups, respectively, and only the placebo was intraperitoneally injected. The third group was intraperitoneally administered with vitamin E (dl/-α-tocopheryl acetate, 100 mg/kg body weight), the fourth group with Se (Na₂SeO₃ 1.5 mg/kg body weight), and the fifth group with vitamin E and Se (dl-α-tocopheryl acetate, 100 mg/kg body weight + Na₂SeO₃ 1.5 mg/kg body weight). This administration was done for three times with overday intervals and the second, third, forth, and fifth group rats were taken to enflurane anesthetise for 2 h. The liver vitamin E level was slightly lower in the anesthesia control group than in control group. However, the liver vitamin E content was significantly (p < 0.05 andp < 0.01) increased in vitamin E, Se, and combination groups, whereas the vitamin A level in liver was not statistically different. In general, plasma levels of alanine aminotransferase, creatin kinase, total bilirubin, urea, red blood cell counts, packet cell volume, and hemoglobulin values were significantly (p < 0.05 andp < 0.001) increased during the anesthesia and returned to near control values after the vitamin E plus selenium injection. However, administration of vitamin E had less effect on the hematological and biochemical parameters compared to that of selenium and their combination with vitamin E. However, the white blood cell count and levels of alkaline phosphatase, aspartate aminotransferase, total cholesterol, triglycerides, total protein, and creatinine were not statistically influenced by the anesthesia. In conclusion, we observed that plasma levels of some enzymes and metabolites were significantly increased in the enflurane anesthesia of rats, whereas the liver vitamin E levels were slightly decreased. Therefore, we observed that vitamin E and selenium have a protective effect against anesthesia complication, but the effect of selenium appears to be much greater than the vitamin E.     

学习记忆对脑内c-fos基因表达的影响

学习记忆是人和动物重要的脑功能，大量事实表明，学习记忆过程与脑内ｃ－ｆｏｓ基因的表达密切相关。由学习记忆所诱导的ｃ－ｆｏｓ基因表达在脑内广泛分布，以皮层、海马和边缘系统为多，依学习记忆训练模型的不同，其表达时程有所差异，但一般于训练后立即或３０分钟左右出现，１～２小时左右达峰值。被动和主动回避训练、光辨别训练及味觉厌恶性条件反射训练等多种学习记忆模型均可诱导脑内ｃ－ｆｏｓ基因的表达。其他影响学习记     

胰岛素对AD模型大鼠空间学习记忆能力的影响

目的:探讨胰岛素对阿尔茨海默氏病(AD)模型大鼠学习记忆能力影响及其可能机制。方法:大鼠海马微量注射Okadaic acid(OA),胰岛素侧脑室注射。水迷宫实验检测大鼠学习记忆能力;Western blotting实验检测大鼠海马烟碱型胆碱能受体的表达;免疫组化观察大鼠脑内胶质纤维酸性蛋白(GFAP)的表达。结果:与对照组比较,模型组大鼠学习记忆能力明显下降(P<0.01),烟碱型胆碱能受体表达减少(P<0.05),GFAP免疫阳性星形胶质细胞增多(P<0.05)。与模型组相比,胰岛素组大鼠学习记忆能力明显提高(P<0.01),烟碱型胆碱能受体表达增多(P<0.05),GFAP免疫阳性星形胶质细胞减少(P<0.05)。结论:胰岛素提高AD模型大鼠的学习记忆能力可能与其改善模型鼠胆碱能系统功能及减少星形胶质细胞增生有关。     

Effects of intraperitoneally‐administered vitamin E and selenium on the blood biochemical and haematological parameters in rats

The aim of this work was to determine the role of intraperitoneally‐administered vitamin E and selenium on the biochemical and haematological parameters in the blood of rats. Thirty‐two adult male Wistar rats were used in this study. All rats were randomly divided into four groups. The first group was used as the control. The second group was intraperitoneally administered with vitamin E (±‐α‐tocopheroryl acetate, 10 mg day⁻¹), the third group with Se (Na₂SeO₃ 0·2 mg over a day), and the fourth group with vitamin E and Se (vitamin E 10 mg + Na₂SeO₃ 0·2 mg over a day). This administration was done for 5 weeks. Blood samples were taken from animals at the end of the dosage period and biochemical parameters in serum samples and haematological parameters in total blood were determined. The levels of total cholesterol (p<0·01) and number of white blood cells (p<0·001) in blood were significantly higher in the vitamin E group than in the control group. The levels of ALP, total cholesterol (p<0·01) and number of white blood cells (p<0·01) in blood were significantly higher in the selenium group than in the controls. The levels of glucose (p<0·05), ALP (p<0·01), total cholesterol (p<0·001) and number of white blood cells (p<0·01) were higher in the vitamin E and selenium combined group than in the controls. Other parameters considered within this trial (ALT, LDH, creatinine, albumin, total protein, amylase, creatine kinase, HDL, triglycerides, total lipid, sodium, chloride, uric acids, red blood cell, haemoglobin, packed cell volume, MCV, MCH, MCHC) did not show statistically significant differences between the control and injected groups. The results indicated that blood glucose and total cholesterol levels, ALP activity and white blood cell counts were significantly increased by intraperitoneal administration of vitamin E and selenium in rats. Copyright © 1999 John Wiley & Sons, Ltd.     

Dietary selenium status and plasma thyroid hormones in chicks

Experiments were conducted to study the effect of marginal levels of selenium and vitamin E on plasma thyroid hormones of meattype chicks. Plasma thyroxine (T₄) was significantly increased when a semipurified diet was supplemented with either selenium or vitamin E. Triiodothyronine (T₃) was also significantly increased by vitamin E and in one experiment with selenium supplementation. No significant increase in these hormones was observed in birds fed a corn-soybean-meal diet supplemented with these nutrients. Plasma corticosterone level was reduced and weight of the bursa of Fabricius increased by selenium or vitamin E supplementation. These nutrients may be necessary for providing the optimum thyroid conditions for activity of thyroid peroxidase.     

Investigations into combined dietary deficiencies of copper,selenium, and vitamin E in the rat

Interactions between dietary Cu, Se, and vitamin E in ascorbate-induced hemolysis of erythrocytes obtained from rats fed diets deficient or adequate in these elements were investigated. Hemolysis was affected by all three dietary factors, through closely interrelated but distinct mechanisms. In vitamin E-deficient cells, hemolysis was increased and the amount of hemolysis was directly related to the amount of hemoglobin breakdown. Deficiency of Cu or Se decreased hemolysis, but only in vitamin E-deficient cells. Vitamin E did not affect the breakdown of hemoglobin, but Cu and Se did. Hemolysis and hemoglobin breakdown were decreased by the addition of glucose, through mechanisms independent of that involving reduced glutathione metabolism. These results suggest that vitamin E acts within erythrocyte membranes to prevent products of hemoglobin breakdown from initiating peroxidation and subsequent hemolysis. Effects of Cu and Se are linked with that of vitamin E by the involvement of glutathione peroxidase and Cu superoxide dismutase in the cytoplasmic breakdown of hemoglobin, rather than by a direct effect of these enzymes on lipid peroxidation. It is concluded that the erythrocyte, because of its high heme content, probably represents a special system in terms of peroxidative pathways, and these findings may not be directly applicable to other tissues.     

Beneficial effect of vitamin E on the metabolic parameters of diabetic rats

The role of vitamin E in the pathogenesis of diabetes mellitus is unknown. The purpose of this study was to examine the effect of oral administration of vitamin E on some of the metabolic parameters of experimental diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (60 mg/kg body weight at 12 weeks of age). Vitamin E (0.2, 0.4, 0.8 mg/kg body weight) was administered orally for a period of 3 weeks to normal and diabetic Wistar rats. In some experiments, Vitamin E was given either before or after the induction of diabetes mellitus. Blood glucose level and weight were recorded for each rat in different groups on a weekly basis. Oral glucose tolerance test (OGTT) was performed on fasted normal, diabetic and vitamin E treated rats at the end of the experiment. Vitamin E significantly (p < 0.01) reduced blood glucose levels in experimental diabetes mellitus at all doses as compared to untreated rats. Vitamin E induced weight loss in normal as well as in diabetic rats. The beneficial effect of vitamin E on the hyperglycaemia of diabetic rats was dose-dependent. Moreover, vitamin E also improved OGTT in diabetic rats compared to untreated diabetics. In conclusion, vitamin E may play a role in glucose metabolism and thus be a useful adjuvant therapy in type I diabetes. (Mol Cell Biochem 261: 35–42, 2004)     

维生素E和硒水平对肉鸡不同自由基代谢的影响

选用200羽14日龄健康AA肉鸡,以电子自旋共振(ESR)捕集法和生物化学法对肉仔鸡血液和组织器官的不同自由基进行直接或间接测定,探讨VE和Se对肉鸡不同自由基代谢的作用及其动态变化.结果表明:组织一氧化氮(NO)自由基水平随日粮VE含量升高而降低,二者呈负相关关系,日粮高水平Se有诱导产生NO自由基的倾向;高VE和Se日粮显著提高血清和肝脏中SOD和GSH-Px的活性,但随处理时间的延长,组织SOD活性逐渐降低,而GSH-Px活性逐渐升高,说明日粮VE和/或Se不足均会诱导机体产生O.2-、H2O2自由基,且O2.-自由基会持续大量产生,而H2O2自由基仅在缺乏初期大量产生,而后趋于缓和;低VE和/或低Se均显著提高组织MDA含量,且低Se比低VE更为显著.VE和Se对肉鸡NO、O.2-和H2O2自由基代谢的作用存在协同效应.     

Comparison of the effects of zinc alone and zinc associated with selenium and vitamin E on insulin sensitivity and oxidative stress in high-fructose-fed rats

PURPOSE: In the present study, we investigated the effect of an association of micronutrients (zinc (Zn), selenium (Se) and vitamin E (vit E)) on insulin activity and antioxidant status in an animal model of insulin resistance, the high-fructose-fed rat. PROCEDURES: Five experimental groups were compared: a control group (C) receiving a standard diet, a high-fructose-fed group (F) where 58% of the diet carbohydrate was fructose, a high-fructose-fed group supplemented with Zn alone (FZn group), a high-fructose-fed group supplemented micronutrients (Zn, Se and vit E) (FMicro group). A fifth group consumed a high-fructose diet and received metformin in the drinking water (200mg/day/rat) (FMet group). Insulin sensitivity was measured using the euglycemic hyperinsulinic glucose clamp technique. Metabolic parameters, trace elements and antioxidant parameters were measured in blood samples from all groups. RESULTS: High-fructose-fed rats were resistant to insulin as indicated by the lower glucose infusion rate. The insulin sensitivity of FZn, FMicro and FMet groups was higher than that of F group, with the highest insulin sensitivity for the FMicro group. No statistically significant difference in glycemia between the groups was observed. The ratio of reduced to oxidized glutathione was higher in FZn and FMicro groups than in all other groups, as a consequence of decreased oxidized glutathione. CONCLUSION: Our results provide direct evidence that micronutrients have a beneficial effect on insulin sensitivity and some components of the antioxidant defense system in an animal model of insulin resistance.     

大鼠学习记忆能力与nov基因表达的关系

采用主动回避法进行大鼠学习记忆训练 ,选出学习成绩好和差的大鼠 ,用原位杂交、免疫细胞化学结合图像分析方法观察nov基因表达的差异。结果显示 ,novmRNA和NOV蛋白阳性神经元主要分布于海马、扣带皮质和联合皮质锥体层、基底神经节和下丘脑等脑区。好成绩组NOV蛋白免疫反应最强 ,阳性细胞最多 ,差成绩组nov基因的表达比假性条件反射组的表达稍强。novmRNA的表达在各组之间无明显的差异。以上结果提示 ,nov基因可能参与学习记忆的调控过程 ,这种调控发生在NOV蛋白翻译水平。     

维生素E在青年和老年大鼠肾脏缺血/再灌注损伤中的作用

目的:探讨维生素E(VE)在青年和老年大鼠肾缺血/再灌注损伤(RI/RI)中的作用。方法:采用夹闭双侧肾动、静脉45min后恢复血流的方法制作RI/RI模型,测定血清中尿素氮(BUN)、肌酐(Scr)、丙二醛(MDA)、超氧化物歧化酶(SOD)、一氧化氮(NO)、诱生型一氧化氮合酶(iNOS)浓度,免疫组化检测肾皮质热休克蛋白70(HSP70)表达。流式细胞术检测肾皮质细胞凋亡率。结果:缺血/再灌注(I/R)后BUN、Scr含量明显升高,老年I/R组MDA含量高于青年I/R组,SOD含量低于青年IR组,HSP70、NO以及肾皮质细胞凋亡率高于control组;VE可显著降低RI/RI大鼠BUN、Scr、MDA、iNOS水平,升高NO和SOD水平,增加HSP70的表达,降低肾皮质细胞凋亡率。结论:VE可通过促进肾组织HSP70的表达,增加NO和SOD水平,提高大鼠体内清除自由基的能力,从而对青、老年大鼠肾缺血/再灌注损伤(RI/RI)起到一定的保护作用。     

Rumen-protected choline and vitamin E supplementation in periparturient dairy goats: effects on milk production and folate, vitamin B12 and vitamin E status

We investigated the effects of rumen-protected choline (RPC) and vitamin E (VITE) administration on milk production and status of folate, vitamin B12 and vitamin E during the periparturient period of dairy goats. Forty-eight Saanen multiparous goats were selected for the 72-day experiment, being moved to a maternity pen 30 days before expected parturition and assigned to one of the four experimental groups: control (CTR), no choline or vitamin E supplementation; choline (RPC), supplemented with 4 g/day choline chloride in rumen-protected form; vitamin E (VITE), supplemented with 200 IU/day vitamin E in rumen-protected form; and choline and vitamin E (RPCE), supplemented with 4 g/day RPC chloride and 200 IU/day vitamin E. Supplements were administered individually before the morning feed to ensure complete consumption, starting 30 days before kidding and continuing for 35 days after. During the experiment, milk yield and 4% fat-corrected milk (FCM) yield were, respectively, 210 and 350 g/day higher in RPC-supplemented goats than in non-supplemented goats. Milk fat concentration and fat yield were also increased by RPC treatment. Milk yield and composition were unaffected by vitamin E supplementation. There were no significant interactions between RPC and VITE for any of the variables measured. Plasma metabolites did not differ between treatments before and after kidding except that plasma folate at parturition was higher in RPC-supplemented goats. Neither choline nor vitamin E affected vitamin B12 plasma concentrations, while a time effect was evident after the second week of lactation, when B12 levels in each treatment group started to increase. Vitamin E administration resulted in plasma α-tocopherol levels that were 2 to 2.5 times higher than in non-supplemented goats. Overall, these results suggest that greater choline availability can improve milk production and methyl group metabolism in transition dairy goats.     

Influence of dietary selenium and vitamin E on the levels of fatty acids in brain and liver tissues of lambs

In this study, the effects of dietary vitamin E, selenium, and their combination on the levels of fatty acid composition of the brain and liver tissues were examined. In brain tissue, the amounts of most fatty acids increased in vitamin E, combination and selenium groups compared with control group values. While the proportions of myristic, pentadecanoic, palmitic, linoleic, and total saturated fatty acids were decreased in vitamin E, Se and combination groups, eicosapentaenoic, total unsaturated and MUFA were increased in the same groups. In addition, the proportions arachidonic, eicosapentaenoic, total unsaturated, ω6 and MUFA in the combination group were higher than in the control group. In liver tissue, the amounts of myristic, pentadecanoic, palmitic, eicosedienoic, eicosapentaenoic, docosahexaenoic, ω3 and PUFA were higher in the combination group than in the control group. Also the proportions of eicosapentaenoic, docosahexaenoic acids in supplemented groups were higher than those in the control group. We conclude that dietary vitamin E and selenium have an influence on the levels of fatty acids in the brain and liver. Copyright © 1999 John Wiley & Sons, Ltd.