水和非水毛细管电泳-电导检测法分离测定水杨酸类药物

目的建立水和非水毛细管电泳-电导法分离水杨酸类药物。方法用未涂层石英毛细管柱(55 cm×50 μm),以10 mmol·L^-1 Tris-30 mmol·L^-1 H₃BO₃(pH 8.0)为运行缓冲液,分离电压为24 kV,进样时间10 s,电导检测法。结果在非水实验条件下,水杨酸(SA)、乙酰水杨酸(ASA)和磺基水杨酸(SSA)得到很好的分离。SA,ASA和SSA的线性范围分别为0.05～100 mg·L^-1,5.0～250 mg·L^-1,0.08～100 mg·L^-1,r均大于0.995。结论应用于阿斯匹林制剂中水杨酸和乙酰水杨酸含量的测定,结果令人满意。与水介质相比,乙醇介质具有更高的灵敏度和分离效率。     

HPLC-ELSD法测定贝母中异甾类生物碱及糖苷类成分的含量

目的建立同时测定贝母中5种异甾类生物碱——peimissine, imperialine, sinpeinine A, imperialine-3β-glucoside和yibeinoside A含量的HPLC分析方法。方法C₁₈柱;流动相:乙腈-水(含0.1%二乙胺);梯度洗脱,流速1.0 mL·min^-1;检测器:Alltech 500蒸发光散射检测器(ELSD)。结果线性范围为peimissine 13.1～288.2 mg·L^-1(r²=0.997 5), imperialine-3β-glucoside 7.7～169.4 mg·L^-1 (r²=0.999 3), yibeinoside A 7.3～160.6 mg·L^-1 (r²=0.999 7), imperialine 16.5～363.0 mg·L^-1 (r²=0.999 2), sinpeinine A 8.7～191.4 mg·L^-1 (r²=0.994 2)。 5个化合物的精密度和重现性RSD均<5%。结论本方法简便、有效、可行,可用于贝母中5种异甾类生物碱的含量测定。     

胶束电动毛细管色谱法分离和测定几种大黄含量

建立了胶束电动毛细管色谱法分离和测定几种大黄中大黄素、芦荟大黄素、大黄酸含量的测定方法。缓冲液为含0.025mol·L^-1十二烷基磺酸钠(简称SDS)的0.025mol,L-13-环己氨基-1-丙烷磺酸(简称CAPS)-乙腈(100:10),pH0.96。线性范围:芦荟大黄素为0.0025～0.0175mg·ml^-1(r=0.9999),大黄素为0.005～0.05mg·ml^-1(r=0.9999),大黄酸为0.005～0.035mg·ml^-1(r=0.9996)。回收率:芦荟大黄素为98.2%～101.8%,大黄素99.9%～101.9%,大黄酸99.2/～101.2%。此法简便、快速、重现性好。     

喹诺酮类药物对茶碱药代动力学的影响

目的探讨喹诺酮类药物对茶碱药代动力学是否存在显著影响,为临床合理用药提供参考。方法采用自身对照法,测定家兔iv 10mg·kg^-1茶碱及每天1次灌服喹诺酮类药物,连续6d,再iv 10mg·kg^-1茶碱后血浆中茶碱浓度,计算药动学参数。结果合用氟罗沙星前后茶碱在家兔体内按一室模型处理。合用前后茶碱的的药动学参数分别为,K:0.154±0.035h^-1,0.151±0.044 h^-1;T_1/2:4.70±1.12 h,4.90±1.38 h;V:0.562±0.180 L·kg^-1,0.556±0.166 L·kg^-1;AUC_0～10:93.70±32.87 mg·h·L^-1,100.20±43.11 mg·h·L^-1;AUC_0～∞:147.87±68.08 mg·h·L^-1,157.16±80.69 mg·h·L^-1;CL:0.090±0.046 L·kg^-1·h^-1,0.091±0.052 L·kg^-1·h^-1;Cmax:19.91±5.25 mg·L^-1,20.12±5.24 mg·L^-1。以上合参数均无显著性差异(P>0.05)。合用氟罗沙星后茶碱的血浆浓度有一定波动,但无统计学意义(P>0.05)。合用芦氟沙星前后茶碱在家兔体内呈一室模型。茶碱的药动学参数分别为,K:0.147±0.017 h^-1,0.148±0.018 h^-1;T_1/2:4.76±0.54 h,4.74±0.56 h;V:0.581±0.089 L·kg^-1,0.555±0.075 L·kg^-1;AUC_0～10:91.42±11.14 mg·h·L^-1,94.97±10.20mg·h·L^-1;AUC_0～∞:119.48±14.96 mg·h·L^-1,124.05±14.76 mg·h·L^-1;CL:0.085±0.011 L·kg^-1·h^-1,0.082±0.010L·kg^-1·h^-1;Cmax:18.48±2.53 mg·L^-1,19.16±2.34mg·L^-1。合用芦氟沙星前后茶碱各参数均无显著性差异(P>0.05)。合用芦氟沙星后茶碱的血浆浓度有升高趋势,但无统计学意义(P>0.05)。合用培氟沙星前后茶碱在家兔体内呈一室模型。茶碱的药动学参数分别为,K:0.150±0.038 h^-1,0.110±0.018 h^-1,P<0.01;T_1/2:4.95±1.67 h,6.69±2.01 h,P<0.01;V:0.584±0.149 L·kg^-1,0.511±0.126 L·kg^-1,P<0.05;AΜC_0～10:97.71±40.09 mg·h·L^-1,126.11±42.72 mg·h·L^-1,P<0.01;AΜC_0～∞:136.05±83.40 mg·h·L^-1,202.10±99.81 mg·h·L^-1,P<0.01;CL:0.091±0.038 L·kg^-1·h^-1,0.056±0.018 L·kg^-1·h^-1,P<0.01;Cmax:18.94±4.89 mg·L^-1,21.82±5.40 mg·L^-1,P<0.05。合用加替沙星前后茶碱在家兔体内按一室模型处理。合用前后茶碱的药动学参数分别为,K:0.147±0.035 h^-1,0.127±0.026 h^-1;T_1/2:4.89±0.98 h,5.62±1.09h;V:0.541±0.162 L·kg^-1,0.538±0.154 L·kg^-1;AΜC_0～10:97.81±29.87 mg·h·L^-1,107.27±39.54mg·h·L^-1;AΜC_0～∞:153.32±65.64 mg·h·L^-1,174.01±71.03 mg·h·L^-1;CL:0.081±0.034 mg·h·L^-1,0.074±0.033 L·kg^-1·h^-1;Cmax:20.51±5.12 mg·L^-1,20.60±5.05 mg·L^-1。合用加替沙星前后茶碱各参数除T_1/2(P<0.05)外无显著差异。结论氟罗沙星、芦氟沙星对茶碱的血药浓度及药代动学参数没有显著影响;培氟沙星对茶碱的血药浓度及药代动学参数有显著影响;加替沙星对茶碱的血药浓度及除T_1/2的药代动学参数没有显著影响。     

苯丙氨酸、蔗糖和甘露醇对杂种红豆杉细胞的生长及形成紫杉醇、巴卡亭III和10-去乙酰基巴卡亭III的影响

研究了苯丙氨酸、蔗糖和甘露醇对杂种红豆杉悬浮细胞的生长及形成紫杉醇、巴卡亭II和10-去乙酰基巴卡亭II的影响。结果表明,培养基中添加1.0mmol·L^-1或2.0mmol·L^-1苯丙氨酸和在培养28d时同时补加73.0mmol·L^-1蔗糖和137.3mmol·L^-1甘露醇能显著地促进细胞的生长和这3种紫杉烷的形成。同对照相比,有苯丙氨酸又补加蔗糖和甘露醇的细胞生物量增加了0.6～0.8倍,紫杉醇的产量增加了9～10倍,巴卡亭II的产量增加了2.5～3.0倍,10-去乙酰基巴卡亭II的产量增加了7倍。在培养28d时补加73.0mmol·L^-1蔗糖能显著地促进细胞的生长,但对细胞中这3种紫杉烷的含量没有显著的影响。     

脑5-HT1A/1B、α2受体及腺苷酸环化酶参与了胍丁胺的抗抑郁作用

为了在单胺受体及受体后腺苷酸环化酶(adenylate cyclase,AC)水平探讨胍丁胺(agmatine,AGM)抗抑郁作用的精细机制,采用小鼠悬尾实验和强迫游泳实验观察AGM抗抑郁行为改变。采用放射免疫方法测定大鼠前额皮层突触膜蛋白AC活性。结果表明,AGM(5～40 mg·kg^-1,ig)在小鼠悬尾实验和强迫游泳实验模型上均有显著抗抑郁活性。同时伍用β受体/5-HT_1A/1B受体阻断剂吲哚洛尔(pindolol, PIN, 20 mg·kg^-1, ip)、 α₂肾上腺素受体拮抗剂育亨宾(yohimbine, YOH, 5～10 mg·kg^-1, ip)或咪唑克生(idazoxan, IDA, 4 mg·kg^-1, ip)对AGM(40 mg·kg^-1, ig)的抗抑郁活性具有显著拮抗效应; 而β受体阻断剂普萘洛尔(propranolol, PRO, 5～20 mg·kg^-1, ip)或5-HT₃受体拮抗剂曲匹西隆(tropisetron, TRO, 5～40 mg·kg^-1, ip)对AGM(40 mg·kg^-1, ig)的抗抑郁活性无显著影响。AGM(0.1～6.4 μmol·L^-1)与大鼠前额皮层提取的突触膜共孵可剂量依赖地激活AC活性, 而PIN(1 μmol·L^-1)或YOH(0.25～1 μmol·L^-1)均显著拮抗AGM(6.4 μmol·L^-1)对AC的激活作用; 慢性给予大鼠AGM(10 mg·kg^-1, ig, bid)或氟西汀(fluoxetine, FLU, 10 mg·kg^-1, ig, bid) 2 w也显著增强大鼠前额皮层基础及Gpp(NH)p 预激活的AC活性。本研究表明, 调节脑内5-HT_1A/1B和α₂等受体功能, 并激活前额皮层AC可能是AGM抗抑郁活性的重要机制之一。     

溴泰君(W198)在大鼠和比格狗体内的药代动力学

目的研究溴泰君(W198)在大鼠和比格狗的药代动力学。方法采用HPLC紫外检测方法测定大鼠及比格狗注射W198后血清药物浓度。结果大鼠iv W198 10,20和40 mg·kg^-1 3个剂量的T_1/2β分别为6.60,7.36和6.77 h,AUC_0-24h分别为3.797,7.371和15.192 mg·h·L^-1,V_d分别为7.14,4.33和4.13 L·kg^-1,CL分别为2.83,2.60和2.71 L·(kg·h)^-1。大鼠im W198 20 mg·kg^-1后T_1/2β为11.61 h,AUC_0-24h为4.191 mg·h·L^-1,im的生物利用度为56.9%。比格狗iv W198 5 mg·kg^-1,T_1/2β为11.72 h,AUC_0-24h为12.646 mg·h·L^-1,V_d为0.70 L·kg^-1,CL为0.46 L·(kg·h)^-1。W198与人血浆蛋白的结合率平均为78.0%。结论W198 im的T_1/2β比iv的略长,其生物利用度为56.9%。在10～40 mg·kg^-1剂量内的吸收呈现一级动力学特征。     

RP-HPLC法测定大鼠血浆中丹参酮IIA浓度及其药代动力学研究RP-HPLC法测定大鼠血浆中丹参酮IIA浓度及其药代动力学研究

目的建立高效液相色谱法测定大鼠血浆中丹参酮IIA浓度的方法。方法血浆样品经液-液萃取后,用HPLC法进行分析。色谱柱为YMC C¹⁸(5 μm,ID 3.0 mm×150 mm);流动相为乙腈-水-冰醋酸(74∶26∶1);流速0.3 mL·min^-1;检测波长270 nm;内标为4-氯联苯。结果线性范围为0.05 mg·L^-1～6.40 mg·L^-1,最低检测浓度为0.05 mg·L^-1。高、中、低3种浓度的平均方法回收率分别为98.9%,102.1%和100.4%。日内、日间精密度(RSD)均小于5%。结论本方法稳定、简便、可靠,可用于丹参酮IIA的血药浓度分析及其药代动力学研究。     

肺热普清散对斑马鱼炎症模型的抗炎作用及机制研究

目的 探讨藏药肺热普清散对斑马鱼炎症模型的作用及机制。方法 挑选受精后 72 h 斑马鱼随机移入 24 孔板中,分为对照组、模型组和肺热普清散低、中、高质量浓度(3、10、30 mg·L^-1)组,对照组与模型组不加药,肺热普清散与斑马鱼共孵育 1 h 后,除对照组外,其余各组用 20 μmol·L^-1硫酸铜处理 2 h 制备炎症模型。在荧光显微镜下观察绿色荧光标记中性粒细胞的 Tg(Lyz:EGFP)系斑马鱼体内炎症细胞迁移情况;实时荧光定量 PCR(qRT-PCR)检测野生型斑马鱼核因子κB2(NF-κB2)、白细胞介素(IL)-1b、肿瘤坏死因子(TNF)-α、IL-8 mRNA 水平;Western blotting 实验检测野生型斑马鱼 NF-κB、TNF-α 蛋白表达水平;免疫荧光法检测各组鱼尾 NF-κB 表达。结果 对照组斑马鱼荧光细胞主要分布于头部和主动脉部,躯干部位主动脉以上荧光细胞稀少;模型组荧光细胞在各区域均增加,显示出炎症细胞向血管外迁移的明显趋势,躯干侧线以上荧光细胞计数较对照组显著增加(P<0.001);肺热普清散 10、30 mg·L^-1组躯干部荧光细胞计数与模型组比较显著降低(P<0.01、0.001)。与模型组比较,肺热普清散 3、10、30 mg·L^-1 组 IL-1b、TNF-α、IL-8 的 mRNA 水平显著下调(P<0.05、0.01),10、30 mg·L^-1 组 NF-κB2 mRNA 水平显著下调(P<0.01);10、30 mg·L^-1 组 NF-κB、TNF-α 蛋白表达水平显著降低(P<0.01、0.001)。免疫荧光结果显示,模型组躯干部位和鱼鳍 NF-κB 白色荧光点较对照组明显增加,经 10 mg·L^-1肺热普清散处理后的相同部位荧光点减少。结论 肺热普清散对硫酸铜诱导的斑马鱼炎症模型具有抗炎作用,机制与抑制 NF-κB、TNF-α 表达有关。     

高效毛细管电泳法同时测定红花中腺苷、芦丁和槲皮素的含量

目的 用高效毛细管电泳法对红花中的有效成分腺苷、槲皮素和芦丁同时进行含量测定。方法 采用熔融石英毛细管柱（66.5 cm×50 μm ID，有效长度58 cm）作为分离通道；以50 mmol·L^-1硼砂其中含18%甲醇的溶液（pH 9.7）为运行缓冲液；运行电压: 24 kV；毛细管柱温: 20 ℃；检测波长： 210 nm。结果 以利福平为内标，腺苷、芦丁和槲皮素分别在10～160 mg·L^-1，100～2 000 mg·L^-1和100～1 600 mg·L^-1 线性关系良好（R>0.998）；平均回收率分别为98.5%～100.5%， 96.9%～99.5%和99.1%～99.5%； RSD分别为6.5%，5.2%和5.6%(N=5)。结论 此法操作简便快速，回收率及重现性好，可作为红花质量控制的方法。     

Effects of the beta 2-adrenoceptor agonist clenbuterol on tyrosine and tryptophan in plasma and brain of the rat

The beta 2-adrenoceptor agonist, clenbuterol (initially 5 mg/kg), was found to significantly reduce plasma tyrosine and raise brain tryptophan levels (P less than 0.01). By comparison, decreases in plasma tryptophan and increases in brain tyrosine were small and often nonsignificant. Amino acid levels measured in different brain regions revealed that the elevations were similar among the cerebellum, striatum, and cortex. These effects were partially blocked by propanolol but not by atenolol. The ED50 was estimated from dose-response curves to be about 0.05 mg/kg for both the decrease in plasma tyrosine and the increase in brain tryptophan. The effects of low doses of clenbuterol were prevented completely by propranolol. Peripheral organs displayed strikingly different patterns of change in amino acid concentrations. Only the spleen had any accumulation of tryptophan, but that was much less than in brain. In contrast, tyrosine and tryptophan were decreased in heart and unaltered in liver; tyrosine was decreased in lung. The elevation in brain tryptophan levels was attenuated by the beta 2-antagonist, ICI 118,551, but not by the beta 1-antagonist, betaxolol; but the reduction in plasma tyrosine was unaffected by either drug. The serotonin antagonist, methysergide, failed to block the effects of clenbuterol. We conclude that changes in amino acid concentrations produced by clenbuterol are mediated by beta 2-adrenoceptor stimulation. Although the increases in brain tyrosine and tryptophan were similar to increases in the plasma ratios of these amino acids to the sum of the other large neutral amino acids competing for transport into the brain, the disparity between the effects of ICI 118,551 in brain and plasma suggests that clenbuterol may also have a direct action in brain to regulate levels of aromatic amino acids. Since clenbuterol has been purported to have an antidepressant effect and since other antidepressants also increase brain tryptophan, this may be a common feature of antidepressant drug action.     

A NOVEL SYNTHESIS OF 2-THIOETHER DERIVATIVES OF TRYPTOPHAN

The reaction of L-3a-hydroxy-1,2,3, 3a, 8,8a-hexahydropyrrolo[2,3-b]indole-2-carboxylic acid (Hpi) with methanethiol, ethanethiol, mercaptoethanol or 3-mercaptopropionic acid in warm aqueous acetic acid gives the corresponding 2-thioether derivatives of tryptophan in 50–80% yield (based on Hpi). Better yields may be obtained in 25% trifluoroacetic acid at room temperature. Cysteine reacts with Hpi to give the double amino acid 2-(L-3-alanylthio)-L-tryptophan (tryptathionine), which is a constituent of the highly poisonous cyclopeptides of Amanita phalloides, such as phalloidin. Reaction of a moderate excess of Hpi with cysteine-SH groups of a tripeptide (glutathione) and a protein (reduced ribonuclease) has also been effected, giving the respective S-tryptophanylated peptide or protein. In both cases, reaction occurred specifically with the -SH groups of cysteine and virtually quantitative covalent binding of tryptophan was verified. The extent of the reaction is easily quantitated by spectrophotometry or by amino acid analysis of the content of oxindolylalanine in the hydrolysate with hot 3-N p-toluenesulfonic acid of the S-tryptophanylated peptide or protein. The reaction should be useful in the field of peptide synthesis, providing a simple method for establishing a cross-link between tryptophan and cysteine, as a basic step in the chemical synthesis of toxic peptides of Amanita phalloides.     

反相离子对色谱法同时测定复方苦参注射液中4个生物碱含量

目的:建立反相离子对色谱同时测定复方苦参注射液中苦参碱、槐果碱、氧化槐果碱和氧化苦参碱含量的方法。方法:色谱条件:Diamonsil C18(250 mm×4.6 mm,5.0μm)色谱柱;流动相为0.04%磷酸-10 mmol·L-1戊烷磺酸钠水溶液(A)和乙腈(B),线性梯度洗脱,流速为1.2 mL·min-1;柱温为30℃;紫外检测波长:210 nm。结果:苦参碱、槐果碱、氧化槐果碱和氧化苦参碱质量浓度分别在18.92～946.0,4.052～202.6,9.293～464.6,34.73～1736 mg·L-1范围内线性关系良好,相关系数均为0.9999;RSD重复性试验中4个生物碱含量均小于2.1%;平均加样回收率分别为98.2%,96.4%,96.9%,97.1%。结论:该方法简便、准确,重复性好,可用于复方苦参注射液的质量控制。     

Effect of aminophylline on tryptophan and other aromatic amino acids in plasma, brain and other tissues and on brain 5-hydroxytryptamine metabolism.

1 Aminophylline and other methylxanthines increase brain tryptophan and hence 5-hydroxytryptamine turnover. The mechanism of this effect of aminophylline was investigated. 2 At lower doses (greater than 100 mg/kg i.p.) the brain tryptophan increase could be explained by the lipolytic action of the drug, i.e. increased plasma unesterified fatty acid freeing plasma tryptophan from protein binding so that it became available to the brain. 3 Plasma unesterified fatty acid did not increase when aminophylline (109 mg/kg i.p.) was given to nicotinamide-treated rats but as both plasma total and free tryptophan rose, a tryptophan increase in the brain still occurred. 4 The rise in brain tryptophan concentration following the injection of a higher dose of the drug (150 mg/kg i.p.) could no longer be explained by a rise of plasma free tryptophan as the ratio of brain tryptophan to plasma free tryptophan rose considerably. Plasma total tryptophan fell and the plasma insulin concentration rose. 5 The increase of brain tryptophan concentration after injection of 150 mg/kg aminophylline appeared specific for this amino acid as brain tyrosine and phenyllanine did not increase. However as their plasma concentrations fell the brain/plasma ratio for all three amino acids rose. 6 The higher dose of aminophylline increased the muscle concentration of tryptophan but that of tyrosine fell and that of phenylalanine remained unaltered. The liver concentrations were not affected. 7 The aminophylline-induced increase of the ratio of brain tryptophan of plasma free tryptophan no longer occurred when the drug was given to animals injected with the beta-adrenoreceptor blocking agent propranolol or the diabetogenic agent streptozotocin. 8 The changes in brain tryptophan upon aminophylline injection may be explained by (a) increased availability of plasma tryptophan to the brain due to increased lipolysis and (b) increased effectiveness of uptake of tryptophan by the brain due to increased insulin secretion.     

HPLC检测大鼠血浆中姜黄素的浓度及其药动学研究

目的建立大鼠血浆姜黄素检测的高效液相色谱方法,研究姜黄素的药动学。方法血浆经乙酸乙酯萃取,以ZORBAX SB-C18（4.6 mm×150 mm,5μm）为色谱柱;流动相为乙腈-水-0.1%TFA（50∶30∶20）,流速为1.0 mL.min-1;检测波长为302（0～5.5 min）、426 nm（5.5～7.5 min）。6只SD大鼠,♂,单剂量静脉给予10 mg.kg-1姜黄素,分别在给药后多点尾静脉采血。用该方法检测血浆中姜黄素的浓度;用DAS计算药动学参数。结果姜黄素浓度在0.05～6.00 mg.L-1内线性关系良好（r=0.999 8）;定量下限为0.05 mg.L-1;低（0.10 mg.L-1）、中（1.00 mg.L-1）、高（4.00 mg.L-1）3个浓度的回收率分别为（99.3±5.4）%,（104.2±4.7）%和（99.8±2.0）%;日内RSD分别为4.49%,3.90%和1.72%,日间RSD分别为4.61%,4.27%和2.00%。大鼠姜黄素静脉注射后,姜黄素在大鼠体内符合二室模型;α相和β相消除半衰期分别为0.08 h和0.75 h。结论本方法准确可靠、简便快速,适用于大鼠血浆姜黄素浓度的测定及其药代动力学研究。     

流动注射双安培法测定异烟肼

目的　建立一种快速准确的在线分析测定异烟肼的电化学方法。方法　基于不可逆电对的双安培检测原理,使用经过恒电位阳极化预处理的双铂电极,在外加电位差为0V时,通过偶合异烟肼在一支铂电极上的催化氧化和另一支铂电极上氧化铂的还原两个不可逆电对,建立了流动注射双安培检测异烟肼的新方法。结果　常用药物赋形剂、无机离子、氨基酸、维生素、蛋白质等共存物均不干扰异烟肼的测定。异烟肼的氧化电流与其浓度在1.0×10^-6 - 1.0×10^-4 mol·L^-1 有良好的线性关系(γ=0.998,n=11)。连续8次测定1.0×10^-5mol·L^-1 异烟肼,电流值RSD =1 8%。结论　该方法有很高的选择性和灵敏度,且简单快速,适用于在线分析。     

水解蛋白注射液中游离氨基酸含量的测定及分析

目的:建立二硝基氟苯(DNFB)柱前衍生化法测定水解蛋白注射液中游离氨基酸含量,并对水解蛋白注射液质量进行分析。方法:采用DNFB为衍生化试剂进行衍生,色谱柱为Diamonsil C18(250 mm×4.6 mm,5μm),流动相为0.05 mol.L-1醋酸钠溶液(含1%N,N-二甲基甲酰胺,调pH为6.4)与50%乙腈水溶液,梯度洗脱,流速1.0 mL.min-1,检测波长360nm。结果:各氨基酸的线性关系良好;平均回收率(n=6)为98.7%～100.8%,RSD为0.46%～3.3%。结论:本研究建立了水解蛋白注射液游离氨基酸测定方法,为质量标准中游离氨基酸含量测定限度的制定提供了依据。     

An amino acid mixture deficient in phenylalanine and tyrosine reduces cerebrospinal fluid catecholamine metabolites and alcohol consumption in vervet monkeys

 An amino acid mixture devoid of tryptophan, given orally, was previously shown to reduce cerebrospinal fluid levels of tryptophan and 5-hydroxyindoleacetic acid in vervet monkeys, as compared to a control mixture containing all essential amino acids. In the present study, we tested the possibility that a similar amino acid mixture containing tryptophan, but devoid of phenylalanine and tyrosine (the amino acid precursors of catecholamine neurotransmitters), would influence dopamine and noradrenaline metabolism. Five hours after the administration of this mixture to vervet monkeys, cerebrospinal fluid levels of homovanillic acid and 3-methoxy-4-hydroxyphenylethylene glycol were reduced by 27.4% and 26.9%, respectively. Both effects were statistically significant. Plasma tyrosine (-30%) and the ratio of tyrosine to the sum of other large neutral amino acids (ΣLNAA) were also significantly reduced. The behavioral efficacy of phenylalanine/tyrosine depletion was compared with that of tryptophan depletion in a primate model of voluntary alcohol consumption. All three drinks lowered alcohol consumption, but the effects of the tryptophan-deficient amino acid mixture were not different from those of the balanced amino acid control. The phenylalanine/tyrosine-deficient drink differentially lowered alcohol consumption, consistent with other data in this species and elsewhere implicating dopamine in the rewarding effects of alcohol. Received: 14 January 1997 / Final version: 10 September 1997     

高效液相色谱法同时测定水氯地搽剂中水杨酸、氯霉素和地塞米松磷酸钠含量

目的建立水氯地搽剂中水杨酸、氯霉素和地塞米松磷酸钠含量的方法。方法采用HPLC法,色谱柱为Zorbax ODS-C18column（150 mm×4.6 mm,5μm）;以甲醇-乙腈-0.05 mol.L^-1磷酸二氢钠溶液（用磷酸调pH至2.5）（50∶4∶46）;流速：1 mL.min^-1;测定波长242 nm;柱温：30℃,进样量：20μL。结果水杨酸、氯霉素和地塞米松磷酸钠的线性范围分别为32.24-257.92 mg.L^-1（r=0.999 5）、19.52-156.16 mg.L^-1（r=0.999 8）、2.00-16.00 mg.L-1（r=0.999 4）,平均回收率分别为99.84%、100.14%和100.09%,RSD分别为0.92%、1.03%和1.56%（n=9）。结论本方法快速、准确,可用于水氯地搽剂的质量控制。     

Effects of MK-771, a novel TRH analog,on brain dopaminergic and serotonergic systems

The effect of acute treatment with MK-771, a thyrotropin-releasing hormone analog, has been investigated on the synthesis and release of dopamine and 5-hydroxytryptamine in rat brain. Single injection of MK-771 in doses of 10 and 15 mg/kg produced a rise in tyrosine hydroxylase activity as well as homovanillic acid level in striatum (a site of nigrostriatal dopamine system) and olfactory tubercles (a site of mesolimbic dopamine system). The dopamine levels remained unchanged (olfactory tubercles, hippocampus) or decreased (striatum, hypothalamus, pons-medulla) after MK-771 treatment. Acute MK-771 injection at the dose of 15 mg/kg increased mid-brain tryptophan hydroxylase activity and tryptophan levels by 26% and 55%, respectively. A consistent increase in the levels of 5-hydroxytryptamine and its metabolite 5-hydroxyindoleacetic acid was reported in several brain areas. These data suggest that MK-771 elicits a marked increase in the synthesis and turnover of brain dopamine and 5-hydroxytryptamine.