Potential protective effects of thiamine supplementation on the ruminal epithelium damage during subacute ruminal acidosis

In ruminants, the ruminal epithelium not only has the function of absorbing nutrients but also is an important tissue to prevent harmful substances in the rumen from entering the blood circulation. Thus, the normal function of ruminal epithelium is critical for ruminants. However, subacute ruminal acidosis induced by high-concentrate diets often damages the barrier function of ruminal epithelium in ruminants. Recently, many studies have shown that dietary supplementation with thiamine is an effective method to alleviate subacute ruminal acidosis. In order to provide theoretical reference for the in-depth study of subacute ruminal acidosis and the application of thiamine in the future, this review introduces the effects of subacute ruminal acidosis on morphological structure, inflammatory response, and tight junction of ruminal epithelium. In addition, this paper summarizes the role of thiamine in maintaining ruminal epithelial function of ruminants during subacute ruminal acidosis challenge.     

酱牛肉加工过程中硫胺素的含量变化研究

采用高效液相色谱法对酱牛肉加工过程中的硫胺素含量变化进行研究。以ZORBAX SB-C18柱(4.6 mm×150 mm,5μm)为色谱柱,以甲醇、乙酸钠(0.05 mol/L,pH值6.5)体积比35∶65为流动相,荧光检测。精密度与重复性试验RSD均在3%以内,加标回收率在93.66%~105.06%。结果表明,酱牛肉中的硫胺素在腌制的过程中含量略有降低(p>0.05),在高温煮制的过程中含量显著降低(p<0.05),低温煮制结束后,含量显著增加(p<0.05)。     

Thiamine (vitamin B1) deficiency in germinating seeds of Phaseolus vulgaris L. exposed to soaking injury

Exogenous application of thiamine (vitamin B1) during imbibition improved germination and seedling development of bean (Phaseolus vulgaris L. cv. Lasso) seeds, which were exposed to soaking injury by submergence. Leaching of the vitamin into the incubation medium was not increased in submerged seeds. However, translocation of the thiamine reserves from the cotyledons to the seedling axis was reduced in response to soaking injury. After exogenous application of free thiamine to the seeds, thiaminedi-phosphate (TDP), which is the physiologically active coenzyme form of thiamine, accumulated in the seedling axis of submerged seeds, suggesting an increased demand for thiamine-dependent metabolic reactions in these tissues. Limited oxygen supply of the seeds during the soaking period induces a shift from respiration to fermentation of carbohydrates. Neither thiamine-dependent ethanolic fermentation, nor ATP production or adenylate energy charge (AEC) of the seedling axis were affected by exogenous thiamine application, suggesting that there is no limitation of thiamine-dependent reactions in the energy metabolism of the seedlings. Thus the physiological mechanisms improving germination and seedling development of submerged seeds in response to thiamine seed treatment are still not clear.     

硫胺素在鸡肌肉中的沉积规律研究

为研究鸡肌肉组织中硫胺素的沉积规律,以如皋鸡和文昌鸡为素材,分不同家系、周龄、组织进行取样,采用高效液相色谱法检测样品中的硫胺素含量。结果显示,不同品种、家系、周龄及组织间硫胺素含量均存在显著或极显著差异（P<0.05或P<0.01）。此外,硫胺素含量的遗传力为0.494,与体重的遗传相关为-0.404。以上结果初步表明,硫胺素在机体的沉积受遗传因素影响,且表现为一定的时间和组织变化规律,可以通过选择进行提高。     

柔嫩艾美耳球虫对盐酸氟乙基硫胺素耐药性的诱导

为评估盐酸氟乙基硫胺素产生抗药性的倾向,采用药物浓度递增法,在实验条件下进行柔嫩艾美耳球虫耐药性的诱导研究。每组动物用10只快大黄肉鸡,每只鸡接种1×105个孢子化卵囊,以50 mg/kg盐酸氨丙啉和盐酸氟乙基硫胺素为起始诱导浓度连续传代,以病变记分、存活率和卵囊数三项指标综合判定耐药性。经过10次传代,盐酸氨丙啉对敏感虫株的ACI为192.6,而对耐药虫株的ACI为109.1;经过12次传代,盐酸氟乙基硫胺素对敏感虫株的ACI为197.5,而对耐药虫株的ACI为110.6,对盐酸氨丙啉耐药虫株的ACI为163.2;结果表明成功地诱导出对盐酸氨丙啉、盐酸氟乙基硫胺素完全耐药的虫株。盐酸氟乙基硫胺素产生耐药速度慢于盐酸氨丙啉,与盐酸氨丙啉有部分交叉耐药性。     

硫胺素在瘤胃内的合成及其在预防亚急性瘤胃酸中毒中的应用

亚急性瘤胃酸中毒是现代集约化反刍动物生产中的常见营养代谢病,揭示亚急性瘤胃酸中毒的发生机制及其预防措施是畜牧业生产中的重要科学问题。本文通过综述硫胺素在反刍动物生产中的应用效果、影响硫胺素合成的因素、硫胺素与亚急性瘤胃酸中毒的关系及其调控亚急性瘤胃酸中毒的可能作用途径,进一步揭示了亚急性瘤胃酸中毒的发生机理和硫胺素的生理作用,并为反刍动物生产提供理论参考。     

Thiamine deficiency affects glucose transport and β‐oxidation in rats

Thiamine is recognized as a cofactor for many enzymes involved in intermediary metabolism responsible for energy production. Animal model of thiamine deficiency (TD) included direct evaluation of glucose uptake by estimation of ³H‐deoxyglucose transport across red blood cells membranes and β‐oxidation of fatty acids in isolated leucocytes. Feeding of animals with the thiamine‐deficient diet (0.018 mg/kg diet) for 30 days resulted in disturbances in energy production. The thiamine intake was limited not only by vitamin B₁ deficiency in the diet, but also by time‐dependent drop of feed consumption by rats fed this diet. At the end of experiment, diet consumption in this group of rats was 52% lower than in the control group. This was accompanied by low glucose uptake by erythrocytes of rats suffering vitamin B₁ deficiency for longer time. At the end of experimental period, glucose uptake was over 2 times lower in TD erythrocytes than in control RBC. Such drop of energy production was not compensated by delivery of energy from fatty acid degradation. In leucocytes from TD rats, the β‐oxidation was also suppressed. Observed significant decrease of serum insulin from 2.25 ± 0.25 ng/ml (day 0) to 1.94 ± 0.17 ng/ml (day 30) might have significant impact on observed energy production disorders. The results from this study indicate that the thiamine deficiency significantly reduces feed intake and causes modest abnormalities in glucose and fatty acid utilization.     

盐酸氟乙基硫胺素的药效学研究

采用人工感染艾美耳球虫模型来评价抗球虫药盐酸氟乙基硫胺素的治疗效果,以期为临床用药提供依据。试验选取鸡240只,随机分为8组,每组30只,其中2组分别为模型组（感染不给药组）和空白对照组,另外6组分别为氨丙啉组、尼卡巴嗪组、马杜拉霉素组及盐酸氟乙基硫胺素组（高、中、低三个剂量）,4种抗球虫药物进行治疗。除空白对照组外,其余各组动物接种球虫孢子化卵囊2.5×105个/只。连续给药5 d,在第7天将240只鸡全部扑杀剖检,根据存活率、相对增重率、卵囊值、病变值计算抗球虫指数（ACI）,进而判定药物的疗效。结果表明,125 mg/kg 氨丙啉组ACI为191.2、125 mg/kg 尼卡巴嗪组ACI为192.9、5 mg/kg马杜拉霉素组ACI为186.7,均大于180,为高效抗球虫药;125 mg/kg 盐酸氟乙基硫胺素组ACI为201.6,为高效抗球虫药。盐酸氟乙基硫胺素的抗球虫效果优于氨丙啉、马杜拉霉素及尼卡巴嗪。     

Effect of inulin and oligofructose enrichment of the diet on rats suffering thiamine deficiency

Thiamine deficiency resulted in inhibition of two main pathways supplying energy to the tissues: glycolysis and β-oxidation. Glycolysis was found to be inhibited to 40% of initial value calculated on the basis of RBC trans-membrane transport of glucose. Prolongation of experiment cause lowering of uptake of this sugar. In rats, energy production from fatty acids (FA) seems to be less sensitive to thiamine deficiency than glycolysis. After 30 days of feeding, utilization of FA in rats was depressed to the 61% of initial value. Thiamine deficiency suppressed insulin secretion, and the changes were statistically significant. Feeding of rats with thiamine restricted diet for 1 month caused the reduction of serum insulin by 14%. In the same animals, trans-membrane glucose transport was reduced over two-times, what might suggest a decreased efficiency of insulin action in such conditions. The kind and concentration of non-digestible fructo-oligosaccharides (FOS) did not affect significantly serum insulin concentration in animals fed thiamine restricted diet. Substitution of a part of wheat starch with FOS has only insignificant compensatory effect on the uptake of glucose. A partial amelioration of the β-oxidation inhibition caused by feeding rats with thiamine deficient diet was observed in animals supplemented with FOS. However, this effect was statistically significant only in rats receiving diet containing 10% of inulin. The effect of supplemented FOS and their concentration on trans-membrane glucose transport in RBC was statistically significant, when pulled supplementation groups were used for statistical evaluation.     

Vitamin values ofPleurotus mushrooms

Ascorbic acid, thiamine, niacin, riboflavin, pantothenic acid and folic acid contents were determined in four different species ofPleurotus mushroom grown on wet chopped unfermented rice straw. The estimated values for the respective vitamins ranged from 92–144, 1.36–2.23, 60.6–73.3, 6.66–8.97, 21.1–33.3 mg and 1222–1412 µg per 100g mushrooms on dry weight basis. These vitamin values were comparable with those ofAgaricus bisporus, but were higher than those ofAuricularia, Lentinus andVolvariella.