Effects of L-lysine monohydrochloride on insulin and blood glucose levels in spinal cord injured rats

Background Hyperglycemia in brain and spinal cord could aggravate neurologic impairment. Recent studies showed that L-lysine monohydrochlonde （LMH） could increase the insulin secretion and regulate the blood glucose level. The aim of the present study was to investigate the effects of LMH on pancreatic islet B cells, the levels of endogenous insulin and blood glucose in spinal cord injured rats.Methods Forty male Wistar rats were divided into four groups, namely, normal control group, model group, high-dose LMH group （621.5 mg/kg equal to LMH 1/8 LD50）, and low-dose LMH group （310.8 mg/kg equal to LMH 1/16 LD50）. The model of spinal cord injured rat was established by hemi-transection at the lower right thoracic spinal cord. LMH was administered via intraperitoneal injection once spinal cord injury was produced in rats. All rats were sacrificed 48 hours after spinal cord injured. The effects of LMH on pancreatic islet B cells, the content of endogenous insulin, end the level of blood glucose were observed with immunohistochemical method, radioimmunoassay method, end biochemical analyzer, respectively. Results The insulin immunohistochemical intensities of islet B cells were significantly weaker in model group then those in normal control group （P 〈0.01）. The levels of endogenous insulin were significantly lower and the blood glucose levels were significantly higher in model group than those in normal control group （P 〈0.01）. The insulin immunohistochemical intensities of islet B cells were significantly stronger in high-dose LMH group then those in model group （P〈0.05）. In addition, we found that the levels of endogenous insulin were significantly higher and the blood glucose levels were significantly lower in high-dose LMH group then those in model group （P 〈0.05）. There were no significant differences in the insulin immunohistochemical intensities of islet B cells, the levels of endogenous insulin and the blood glucose between low-dose LMH group and model group （P 〉0.05）. Conclusion LMH, but dose-dependent, might participate in the regulation of pancreatic islet B cells, and then reduce the blood glucose levels in the spinal cord injured rats.

Effects of L-lysine·H2SO4 product on the intestinal morphology and liver pathology using broiler model

Background: Lysine is used widely in livestock production due to the shortage of feed protein resources.Llysine·H2SO4 contains L-lysine sulphate as well as fermentation co-products which contain other amino acids and phosphorus.However,there are few articles about L-lysine·H2SO4 product regarding intestinal morphology and liver pathology of broiler chickens.In this article,we focus on the absorption and metabolism of L-lysine·H2SO4 revealed in the variation of intestinal morphology and liver pathology to determine the tolerance of chicks for L-lysine·H2SO4.Methods: To evaluate the tolerance of broilers for L-lysine·H2SO4,240 one day old broilers were allocated randomly to one of five dietary treatments which included corn-soybean diets containing 0,1%,4%,7% or 10% L-lysine·H2SO4(L-lysine content = 55%).Results: Supplementation of 1% L-lysine·H2SO4 in the diet had no negative effects.However,4%,7% or 10% Llysine·H2SO4 supplementation produced negative responses on broiler performance,carcass characteristics,blood biochemistry,and particularly on intestinal morphology and liver pathology compared with broilers fed the control diet.Conclusion: Our results show that supplementation with 1% L-lysine·H2SO4 had no negative effects on performance,carcass characteristics,blood biochemistry,intestinal morphology and liver pathology in broilers,but supplementation with 4%,7% or 10% L-lysine·H2SO4 produced a negative response,particularly with respect to intestinal morphology and liver pathology.

Escherichia coli Protoplast Fusion and Screening of High L-Lysine-Producing Strain

[Objectives]Protoplast fusion of two parental strains with weak L-lysine production ability was carried out to obtain new fusion strains with strong L-lysine production ability.[Methods]The effects of bacterial age,lysozyme concentration,enzymolysis temperature and time on the protoplast formation rate and regeneration rate were investigated by single factor experiments.On this basis,with the protoplast formation rate as an index,the protoplast preparation process was optimized by an orthogonal experiment.[Results]Bacterial age and enzymolysis time had a greater impact on the protoplast formation rate,followed by enzymolysis temperature and lysozyme concentration.The optimal process for the preparation of L-lysine-producing Escherichia coli protoplasts was to prepare parental protoplasts from bacterial cells cultured for 15 h in the late logarithmic growth phase by enzymolysis with 0.8 mg/ml lysozyme at 37℃for 180 min and promote fusion with PEG6000.In order to facilitate the screening of fusion protoplasts,the empty plasmids p ET-28a and p ET-Duet were transformed into L-lysine-producing E.coli,respectively,and strains p ET-28a-lys01 and p ET-Duet-lys01 were obtained.Fusion strains were then obtained through protoplast fusion.Double-resistance KA1-10were screened on plates containing kanamycin and ampicillin,and a high-yielding fusion strain KA8,which produced L-lysine,was screened by fermentation experiments finally.[Conclusions]The results of this study provide a reference method for further improving the yield of L-lysine and other amino acid strains.

Effect of L-lysine in culture medium on nodule formation by bone marrow cells

The aim of this study was to estimate the effect of L-lysine on nodule formation by rat bone marrow cells in vitro. In this study, L-lysine was added to medium for mesenchymal stem cell culture to promote proliferation and differentiation of the cells, and then nodule formation was estimated in an in vitro rat bone marrow cell culture. Bone marrow cells from the bone shafts of the femora of Fischer 344 rats were cultured in minimum essential medium with 20 μl of L-lysine solution at 10﹣4, 10﹣5, 10﹣6, 10﹣7 or 10﹣8 M. Dexamethasone was also added to the medium at 10 nM for differentiation of stem cells from bone marrow into osteoblast progenitor cells. The subculture was performed for 2 weeks. The quantity of osteocalcin in rat bone marrow cell culture with dexamethasone was 392 ng/ml. In the medium with dexamethasone and 10﹣8 M L-lysine, the quantity of osteocalcin was 437 ng/ml. Nodules only formed upon addition of 20 μl of L-lysine at 10﹣8 M. It was indicated that 10﹣8 M L-lysine should be the optimal concentration for calcification. For nodule formation by rat bone marrow cells in vitro, the optimum concentration of L-lysine in culture medium might be 20 μl of 10﹣8 M. L-lysine could play an important role in matrix production for bone formation in vitro.

Dissolution of highly molecular weight cellulose isolated from wheat straw in deep eutectic solvent of Choline/L-Lysine hydrochloride

Green solvents for cellulose dissolution is a key topic for green chemistry,especially natural cellulose with high molecular weight,and there are scarce solvents reported.Deep eutectic solvent(DES)is a typical kind of green solvent that has been attracted much attention recently.Here,high molecular weight natural cellulose(DP>3000)was first isolated from wheat straw and then be directly dissolved in the choline/L-lysine(Ch/Lys)DES.The solution owns excellent stability,and the solubility reaches^5%.Rheological studies revealed that the natural cellulose can be well dispersed in the DES solution and showed gelation at high concentrations.The dissolved cellulose can be regenerated when the dilute acid aqueous solution was added into the solution.It provides an energy conversation and an environmentally friendly route to prepare a cellulose solution,which makes it possible to convert cellulose to valuable chemicals and materials in its homogeneous solution.

A NEW BIFUNCTIONAL CHELATING AGENT α,ε-N,N'-BIS(L-CYSTEINYL)-L-LYSINE FOR RADIOLABELLING OF MONOCLONAL ANTIBODIES WITH TECHNETIUM-99M

α,ε-N,N'-bis(L-cysteinyl)-L-lysine was synthesized and char- acterized for the first time.It was then employed as a bifunctional chelating agent to chelate technetium-99m and subsequently conjugated to fragment F(ab')_2 of anti-gastric tumor monoclonal antibody 3G9.The radiolabelled antibody was satisfactorily stable and immunoreactive.

Composite Eu-MOF@CQDs“off&on”ratiometric luminescent probe for highly sensitive chiral detection of l-lysine and 2-methoxybenzaldehyde

The high amount of l-lysine can increase the potential risk of cardiovascular disease.Additionally,2-methoxy benzaldehyde(2-MB)has high toxicity and can easily pollute the environment.In this work,carbon quantum dots(CQDs)can be encapsulated into Eu-BTB(H_(3)BTB=1,3,5-tri(4-carboxyphenyl)benzene),forming the multi-emission composite material Eu-BTB@CQDs.It has two emissions peaks(617 nm for Eu and 470 nm for CQDs).Eu-BTB@CQDs can be applied as bi-functional ratiometric“off&on”luminescent sensor for l-lysine and 2-MB with high sensitivity and selectivity,the low limit of detection(LOD)for l-lysine is 3.68μmol/L and for 2-MB is 0.54μmol/L,respectively.Additionally,Eu-BTB@CQDs can quantitatively discriminate l-lysine in the mixed d-and l-lysine water solutions(five different concentrations ratio of l/d-lysine has been set)makes the chiral detection of l-lysine are more meaningful.On the other hand,Eu-BTB@CQDs also can detect 2-MB over 4-methoxybenzaldehyde(4-MB)with high selectivity.Further the detection of 2-MB and l-lysine in the lake water real samples with the reasonable recovery rate.Finally,the detection mechanisms for l-lysine and 2-MB were also investigated and discussed in detail.

Dual-emission carbonized polymer dots for ratiometric sensing and imaging of L-lysine and pH in live cell and zebrafish

It is highly desired to accurately and selectively detect and image intracellular L-lysine and pH in biological systems because they could act as the biomarkers in certain abnormal conditions and may give us a warning of the occurrence of diseases.It has been attracted more focuses to design new ratiometric fluorescent probe for monitoring L-lysine and pH to improve detection accuracy.Carbonized polymer dots(CPDs),which possess carbon/polymer hybrid structure rather than pure carbon structure and constitute of a carbon core and large amounts of functional groups/polymer chains on the surface,rise up as a new type of fluorescent nanomaterials and especially display many advantages for bioanalysis.In this study,o-phenylenediamine(o-PD)and poly(styrene-co-maleic anhydride)(PSMA)are used as the precursors to synthesize the desired CPDs through one-step hydrothermal amide method.The prepared CPDs display two well-resolved fluorescence emission bands,i.e.,a very weak emission centered at 470 nm in blue region and a strong emission centered at 558 nm in yellow region.It is found that the two emissions are both responsive to L-lysine based on the surface passivation mechanism,whereas,only the yellow emission is responsive to pH due to the protonation/deprotonation process of the amino groups.Based on the different responsive behaviors,ratiometric detection and imaging of L-lysine and pH are achieved.The prepared ratiometric CPDs probe is successfully applied for L-lysine and pH sensing and imaging at two emission channels in live cell and zebrafish with satisfactory results.

L-盐酸赖氨酸对局部脑缺血大鼠的治疗作用

目的：研究Ｌ盐酸赖氨酸对大鼠局限性脑缺血的治疗作用。方法：采用电凝阻断大鼠一侧大脑中动脉造成局限性脑缺血模型。结果：一侧大脑中动脉阻断后１５ｍｉｎｉｐＬ盐酸赖氨酸６２１５及３１０８ｍｇ·ｋｇ－１，能显著降低局限性脑缺血大鼠的脑梗塞面积，减少相关脑区变性、坏死神经元的数量，而且Ｌ盐酸赖氨酸６２１５ｍｇ·ｋｇ－１还能明显改善大鼠的神经功能缺失，降低行为评分。结论：Ｌ盐酸赖氨酸对脑缺血有治疗作用。

L-瓜氨酸和L-高瓜氨酸的制备

以L-鸟氨酸盐酸盐为原料与碱式碳酸铜反应生成二鸟氨酸合铜保护α-NH2,用尿素对δ-NH2进行甲酰化,得到二瓜氨酸合铜,后用H2S除铜离子得到L-瓜氨酸。用同样方法以L-赖氨酸盐酸盐为原料制备了L-高瓜氨酸,通过IR,元素分析和高效液相色谱证明了其结构和含量。

康脑灵对大鼠缺氧状态下脑保护作用的定量脑电图

目的：通过皮层脑电（ＥＣｏＧ）的定量分析评价康脑灵（ＫａｎｇＮａｏＬｉｎ，ＫＮＬ）对缺氧状态下大鼠的脑保护作用。方法：用定量方法分析在体脑电在正常供气与停止呼吸情况下的变化，判断药物的脑保护作用。结果：ｉｇ康脑灵可以显著延长停止供气后脑电平均振幅到达最低点的时间，促进重新供气后脑电活动的完全恢复。这种作用在０６３ｇ·ｋｇ－１和１２６ｇ·ｋｇ－１间呈剂量依赖性，与对照组有极显著差异，与氟桂嗪组（２５ｍｇ·ｋｇ－１）无显著性差异。其中康脑灵１２６ｇ·ｋｇ－１组在缺氧２ｍｉｎ时脑电不完全消失。ｉｇ康脑灵可以不同程度地降低皮层脑电的平均振幅。结论：ｉｇＫＮＬ在一定剂量范围内有明显的抗脑缺氧的作用。

氨基胍单盐酸盐的合成及对大鼠半乳糖性白内障预防作用的研究

初步探讨了氨基胍单盐酸盐 (AG)对大鼠半乳糖性白内障的预防作用和AG及其双盐酸盐 (2AG)对非酶糖基化反应 (NEG)的作用。实验结果表明 :AG降低了白内障大鼠晶状体的平均浊度、最高浊度和混浊面积 ,推迟了大鼠半乳糖性白内障的发生 ;在 1.0及 10 .0mmol·L-1浓度下 ,2AG抑制NEG的作用稍强于AG。

盐酸环丙沙星三元配合物体系的光谱研究及应用

研究了盐酸环丙沙星、茜素和稀土镧离子所形成的三元配合物体系。结果表明，以水-乙醇作为溶剂，在pH为5．8的KH2PO4-NaOH缓冲液中，该三元配合物最大吸收波长为280nm，表观摩尔吸收系数为4．23×10^4L·mol^-1·cm^-1，盐酸环丙沙星在0．3～34．5mg／L范围内符合郎伯-比耳定律，方法的检出限为0.01mg／L。已用于市售盐酸环丙沙星片和胶囊的测定。

一种新型食品防腐剂——L-月桂酰胺精氨酸盐酸盐乙醇酯

阐述了L-月桂酰胺精氨酸盐酸盐乙醇酯的物化性质、抑菌活性、抑菌机理、安全性以及在食品和化妆品等领域的应用,为我国研究和开发新型、安全、高效的食品防腐剂提供参考。

L-瓜氨酸与L-高瓜氨酸的合成

以L-鸟氨酸盐酸盐为原料与五水硫酸铜反应生成二鸟氨酸合铜保护α-NH2,用尿素对δ-NH2甲酰化得到二瓜氨酸合铜,后用二水合草酸脱α-NH2保护得到目标产物L-瓜氨酸,总收率49.5%。用同样的方法以L-赖氨酸盐酸盐为原料制备了L-高瓜氨酸,总收率53.5%。产物经IR、熔点、旋光确证。该方法具有操作方便、安全、经济和环保等特点。

配种前母体营养影响子代雄性比率的研究

以初产昆明小鼠为材料,配种前在其母鼠日粮中加入不同组合的3种物质。在3次实验的635只母鼠中得到395窝仔鼠。结果表明:日粮中添喂25%葡萄糖能显著降低子代雄性比率,且产仔数不受影响;添喂3%氯化钠使性比和产产仔数均降低;0.7%精氨酸盐的添加中未显示出对性比的影响;上述3种物质以不同浓度的组合都显示出性比降低、产仔数未受影响的效应。80只母鼠配种前血清睾酮含量分析,发现添喂葡萄糖或葡萄糖、精氨酸盐酸盐、氯化钠混合物使母鼠血清睾酮含量降低。

1,3-二氨基胍盐酸盐的高效液相色谱分析

提出用高效液相色谱法测定1，3-二氨基胍盐酸盐的含量，选用甲醇与乙酸铵缓冲盐体积比75：25为流动相，c8色谱柱，检测波长314nm。试验结果表明：测试结果的相对标准偏差小于2．03％；回收率在97．8％～100．2％；1，3-二氨基胍盐酸盐和三氨基胍盐酸盐得到较好的分离。该法操作简单、实用且定量分析结果准确稳定。

微波辅助合成L-瓜氨酸

以L-鸟氨酸盐酸盐为原料,经配位反应保护α-NH2,后经δ-NH2甲酰化,在微波辐射下去除铜离子,制得目标产物L-瓜氨酸,总收率90.3%。探讨了配合反应中配合试剂的选择、脱保护反应中除铜试剂的选择以及微波辐射功率、微波辐射时间对反应的影响,确定最佳合成条件。产物经红外光谱、熔点和旋光确证。该工艺更安全、环保,且操作方便。

N-保护鸟氨酸的合成

以L-鸟氨酸盐酸盐为原料,经碱式碳酸铜配合α-氨基,在δ-氨基上引入苄氧羰基,用EDTA-2Na脱去α-氨基上的铜离子,得到Nδ-苄氧羰基-L-鸟氨酸,再在α-氨基上引入叔丁氧羰基,得到Nδ-苄氧羰基-Nα-叔丁氧羰基-L-鸟氨酸,用Pd/C与甲酸铵选择性脱去苄氧羰基,得到Nα-叔丁氧羰基-L-鸟氨酸,共得到3个N-保护鸟氨酸产物,收率分别为73.1%、61.2%、52.8%(均以L-鸟氨酸盐酸盐计)。探讨了EDTA-2Na作为脱铜试剂以及催化转移加氢选择性脱苄氧羰基反应的最佳合成条件,产物结构经1H NMR及元素分析确证。该合成工艺操作简便,环境污染较少,产品收率与纯度均较好。

LMH对脑损伤后大鼠胰岛细胞及血糖含量的影响

目的 观察L 盐酸赖氨酸(LMH)对脑损伤后大鼠胰高血糖素细胞(A)、胰岛素细胞(B)和生长 抑素细胞(D)及血糖含量的影响。方法 采用落体法致大鼠脑损伤模型;伤后立刻一次腹腔注射LMH,24h 后断头处死全部大鼠,用免疫组织化学方法观察LMH对脑损伤后大鼠胰岛A、B和D细胞的影响;用生化分 析仪测定血糖含量。结果 与对照组比,脑损伤组大鼠胰岛A、D细胞免疫反应明显增强(P<0.05),胰岛B 细胞免疫反应明显减弱(P<0.05),血糖含量明显增高(P<0.05)。LMH组大鼠胰岛A细胞免疫反应明显 弱于脑损伤组(P<0.05),但与对照组相比无明显差异(P>0.05);胰岛B、D细胞免疫反应与脑损伤组无 明显差异(P>0.05);LMH组血糖含量低于脑损伤组(P<0.01)。结论 LMH在大鼠脑损伤过程中可能 参与了胰岛A细胞功能的调节,并产生显著的降血糖作用。