甲基丙二酸尿症合并同型半胱氨酸血症致多系统损害

目的 甲基丙二酸尿症合并同型半胱氨酸血症是甲基丙二酸尿症中的特殊类型,对5例患儿进行回顾性分析,研究本症的临床表现、生化特点、诊断与治疗方法。方法 应用气相色谱-质谱联用分析法（gas chromatography-mass spectrometry,GC-MS）进行尿有机酸分析,采用荧光偏振免疫测定法检测血浆同型半胱氨酸。确诊后给予钴胺素、左旋肉碱、甜菜碱等药物治疗,予以长期随访。结果 5例患儿（男2例,女3例）起病年龄3个月～13岁。4例表现为进行性智力运动障碍伴蛋白尿、血尿,1例因肌肉酸痛就诊,伴抽搐2例,伴周围神经损害2例,肝功异常2例。5例患儿尿甲基丙二酸为29．4～805．9mg／g肌酐（正常对照为0．2～3．6mg／g肌酐）,血浆中同型半胱氨酸42．5～215．22μmol／L（正常对照5～15μmol／L）,均明显增高,血浆游离肉碱浓度下降。经维生素B12左旋肉碱治疗后,患儿尿甲基丙二酸浓度明显下降,经甜菜碱治疗后血浆同型半胱氨酸逐渐降低。结论 甲基丙二酸尿症并同型半胱氨酸血症可导致多系统损害,临床表现多样;早期诊断、早期治疗是改善预后的关键;对不明原因的脑病、周围神经病、肾损害等多脏器损害患者,应尽早进行尿有机酸分析等特殊检查,对于甲基丙二酸尿症患者应进行血浆同型半胱氨酸测定。     

Expression of aldose reductase, sorbitol dehydrogenase and Na+/myo-inositol and Na+/Cl–/betaine transporter mRNAs in individual cells of the kidney during changes in the diuretic state

 The effect of changes in medullary extracellular tonicity on mRNA expression for aldose reductase (AR), sorbitol dehydrogenase (SDH), Na⁺/Cl^–/betaine (BGT) and Na⁺/myo-inositol (SMIT) cotransporter in different kidney zones was studied using Northern blot analysis and non-radioactive in situ hybridization in four groups of rats: controls, acute diuresis (the loop diuretic furosemide was administered), chronic diuresis (5 days of diuresis), and antidiuresis [5 days of diuresis followed by 24 h deamino-Cys¹,d-Arg⁸ vasopressin (dDAVP)]. Acute administration of the loop diuretic furosemide significantly reduced AR, SMIT and BGT gene expression in the inner and outer medulla compared with controls. Administration of dDAVP to chronically diuretic rats raised the expression of these three mRNAs in the inner but not the outer medulla compared with the chronically diuretic rats. None of these alterations in medullary tonicity significantly changed SDH expression. The in situ hybridization studies showed AR, BGT and SMIT mRNAs to be expressed in both epithelial and non-epithelial cells of the outer and inner medulla. The various cell types (epithelial, endothelial and interstitial cells) differed in their expression pattern and intensity of AR, SDH, BGT and SMIT mRNA, but the inner medullary cells responded uniformly to a decrease in extracellular tonicity with a reduction, and to an increase with enhancement of their AR, BGT and SMIT expression. Received: 26 May 1998 / Accepted: 14 September 1998     

甜菜碱对HepG2人肝癌细胞[Ca2+]i和细胞膜电位的影响

目的研究甜菜碱对肝癌HepG2细胞内游离Ca2 浓度([Ca2 ]i)和细胞膜电位的影响。方法Fluo-3/AM标记,激光扫描共聚焦显微镜观察HepG2细胞[Ca2 ]i,TMRE标记,激光扫描共聚焦显微镜测定细胞膜电位的影响。结果甜菜碱能够升高HepG2细胞[Ca2 ]i,降低细胞膜电位。升高[Ca2 ]i的强度具一定的剂量依赖性,随甜菜碱剂量的增大而升高。甜菜碱50、25mg/mL组与对照组比较差异非常显著(P<0.01),甜菜碱12.5mg/mL组与对照组比较差异显著(P<0.05)。给药48h时间段内细胞内的[Ca2 ]i升高的幅度较大,72h升高幅度相对较小。而降低膜电位上,在48h时间段内,甜菜碱50、25、12.5mg/mL各组膜电位均显著高于对照组(P<0.05),但在72h时间段内甜菜碱12.5mg/mL组与对照组比较没有显著性差异(P>0.05)。结论甜菜碱通过开放细胞膜上的通透性转换孔道(MPTP),从而升高HepG2细胞[Ca2 ]i,启动细胞凋亡机制,诱导HepG2细胞凋亡。     

Serotonin excites neurons in the human submucous plexus via 5-HT3 receptors

BACKGROUND & AIMS: Serotonin (5-hydroxytryptamine [5-HT]) is a key signaling molecule in the gut. Recently, the neural 5-HT3 receptor received a lot of attention as a possible target in functional bowel diseases. Yet, the 5-HT3 receptor-mediated changes in properties of human enteric neurons is unknown. METHODS: We used a fast imaging technique in combination with the potentiometric dye 1-(3-sulfonatopropyl)-4-[beta[2-(di-n-octylamino)-6-naphthyl]vinyl]pyridinium betaine to monitor directly the membrane potential changes in neurons of human submucous plexus from surgical specimens of 21 patients. An Ussing chamber technique was used to study 5-HT3 receptor involvement in chloride secretion. RESULTS: Local microejection of 5-HT directly onto ganglion cells resulted in a transient excitation of enteric neurons characterized by increased spike discharge. This response was mimicked by the 5-HT3 receptor agonist, 2-methyl-5-HT, and blocked by the 5-HT3 receptor antagonist, tropisetron. The proportions of 5-HT-responsive nerve cells per ganglion ranged from 25.5% +/- 18.4% in the duodenum to 54.2% +/- 46.9% in the colon. Interestingly, 2-methyl-5-HT did not evoke chloride secretion in the human intestine but it did in the guinea-pig intestine. Specific 5-HT3A and 5-HT3B receptor subunit immunoreactivity as well as 5-HT3A and 5-HT3B receptor-specific messenger RNA were detected in the tissue samples. Based on co-labeling with the pan-neuronal marker HuC/D we conclude that submucous nerve cells potentially express heteromeric 5-HT3A/B receptors. CONCLUSIONS: We show that 5-HT excited human enteric neurons via 5-HT3 receptors, which may comprise both 5-HT3A and 5-HT3B receptor subunits.     

肉苁蓉药材质量标准的研究

目的 :制订肉苁蓉药材的质量标准。方法 :建立 5种活性成分类叶升麻苷、松果菊苷、肉苁蓉苷A、甜菜碱和甘露醇的TLC定性鉴别及类叶升麻苷的RP HPLC测定方法。结果 :14个药材和 11个饮片样品的薄层色谱斑点清晰 ,专属性强 ;麦角甾苷在 0 15～ 1 2 0 μg线性关系良好 ,平均回收率 98 0 % ,RSD 0 95 %。结论 :本法可作为肉苁蓉药材的质量控制标准。     

Lipotropic capacity of raw plant-based foods: A new index that reflects their lipotrope density profile

Among all of the phytomicronutrients, lipotropes which limit excess hepatic fat deposits, have been very little studied. And yet, liver steatosis is common to several chronic diseases. Among the lipotropes, betaine, choline, myo-inositol, methionine, magnesium, niacin, pantothenic acid and folates were the ones for which sufficient data have possibly been found to allow the selection of a significant number of plant-based foods (PBFs). Our objectives were to unravel the differences or similarities in the lipotrope density (LD) profile of raw PBFs and to define an index reflecting lipotrope contents. From databases for betaine and choline contents, we selected 56 raw PBFs (38 when inositol content was taken into consideration). Lipotropic capacity (LC) was defined as the means of the 8 LD profiles, each expressed as a percentage of raw asparagus LD, which has the highest mean ranking for the 8 LDs (LC = 100). LCs ranged from 7 (grapes) to 672% (spinach), relative to asparagus LC. Among cereal, fruit, legume and seed groups, quinoa, blackberry, common bean and sesame seed had the highest levels of LC (155%, 107%, 36% and 26%, respectively). On a 100 kcal-basis, vegetables are the best sources of lipotropes, followed by cereals, fruits and legumes, then nuts and seeds. PBF LD profiles were complementary but more diversified compared to animal-based food LD profiles.     

HHcy ED大鼠血浆内Hcy的含量对阴茎海绵体CO/HO-2影响的研究

目的:研究高同型半胱氨酸血症(HHcy)勃起功能障碍大鼠体内一氧化碳/血红素加氧酶2(CO/HO-2)体系的变化。方法:雄性4周龄Wistar大鼠40只,体重280～310 g,正常喂养1周后,随机分为正常对照组(A组,10只),余30只给予3%蛋氨酸饲料4周后,测定尾静脉血Hcy,将Hcy>16.0μmol/L的大鼠确定为HHcy,由此确定造模成功。将模型组随机均分为B组(HHcy大鼠模型组,继续给予3%蛋氨酸饲料喂养),C组(HHcy盐酸甜菜碱治疗组,每天继续给予3%蛋氨酸饲料喂养,下午定时给予60 mg/kg甜菜碱,0.3 ml生理盐水溶液灌胃)和D组[每日给与锌卟啉IX腹腔内注射45μmol/(kg.d)],4周后处死大鼠提取标本血检测Hcy含量、阴茎海绵体中Hcy的含量及阴茎组织CO测定。分别于4周和8周2个时间点进行阿朴吗啡实验。结果:比较4组大鼠血浆Hcy浓度、阴茎勃起次数、阴茎海绵体组织CO浓度及阴茎组织血管中HO-2阳性细胞数量的检测结果,与A组[(12.55±0.82)μmol/L、(1.88±0.05)次、(10.55±1.73)μmol/L、6 059±1 257]比较,B组[(25.01±0.94)μmol/L、(0.70±0.05)次、(9.51±1.52)μmol/L、2 595±514]血浆中Hcy水平显著上升(P<0.05),阴茎勃起次数、CO的含量与HO-2阳性细胞均下降(P<0.05或P<0.01),并且Hcy与阴茎勃起次数呈负相关性(P<0.01);C组[(14.37±0.47)μmol/L、(1.18±0.08)次、(10.36±1.56)μmol/L、6 295±1 156]与B组比较,阴茎海绵体内Hcy含量下降,而CO与HO-2含量明显升高,阴茎勃起次数明显升高,有统计学意义(P<0.05或P<0.01)。结论:阴茎海绵体中的CO含量及阴茎海绵体HO-2表达减低可能是导致HHcy大鼠勃起功能障碍的原因之一。甜菜碱降低血浆Hcy浓度,增加阴茎海绵体中CO含量,是治疗HHcy勃起功能障碍的机制之一。     

甜菜碱对肝纤维化大鼠肺组织氧化应激的影响

目的：观察甜菜碱对肝纤维化大鼠肺组织氧化应激的影响。方法：复合致病因素诱导复制肝纤维化大鼠模型,给予甜菜碱[500 mg/（kg·d）]进行干预。4周末,测定大鼠血浆内毒素、白蛋白、总胆固醇、甘油三酯、透明质酸含量及碱性磷酸酶活性;观察肝组织及肺组织的病理学改变;检测肺组织匀浆中TNF-α、ONOO-、NO、MDA的变化。结果：肝纤维化组动物血浆内毒素、白蛋白、总胆固醇、甘油三酯、透明质酸含量明显增高、碱性磷酸酶活性增加,肺组织 TNF-α、NO、ONOO-、MDA 含量均升高;给予甜菜碱后大鼠血浆内毒素及其余各项指标水平均降低,肺组织中 TNF-α、ONOO-、NO、MDA明显降低,尤以TNF-α和MDA的变化更为显著,肺组织的病理学改变也减轻。结论：（1）肝损伤及肝纤维化可导致肺部损伤。（2）甜菜碱可能通过某种机制降低肠源性内毒素水平,进而降低炎性因子水平、减轻肺组织的氧化应激反应,减轻肺损伤。     

甜菜碱合成新工艺的研究

报道了合成甜菜碱的新工艺。该法通过氢氧化钙和氯乙酸的中和,氯乙酸钙的三甲胺化两步反应,最后提纯分离制取甜菜碱,产品甜菜碱含量达到（98±1）%。