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1.
Since kainate evokes large non-desensitizing currents at α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, kainate is of limited use in discriminating between AMPA and kainate receptors. Following recent reports that (2S,4R)-4-methylglutamate is a kainate receptor-selective agonist, we have radiolabelled and subsequently characterized the binding of [3H]-(2S,4R)-4-methylglutamate to rabbit whole-brain membranes. [3H]-(2S,4R)-4-methylglutamate binding was rapid, reversible and labelled two sites (KD1 = 3.67 ± 0.50 nM/Bmax1 = 0.54 ± 0.03 pmol/mg protein and KD2 = 281.66 ± 12.33 nM/ Bmax2 = 1.77 ± 0.09 pmol/mg protein). [3H]-(2S,4R)-4-methylglutamate binding was displaced by several non-NMDA receptor ligands: domoate > kainate -quisqualate -glutamate > 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX) (S)-AMPA = (S)-5-fluorowillardiine > NMDA. Neither the metabotropic glutamate receptor agonists (1S,3R)-ACPD or -AP4, together with the -glutamate uptake inhibitor -trans-2,4-PDC, influenced binding when tested at 100 μM. We conclude that [3H]-(2S,4R)-4-methylglutamate is a useful radioligand for labelling kainate receptors. It possesses high selectivity, and possesses a pharmacology similar to that for rat cloned low-affinity (Glu5 and 6) kainate receptor subunits.  相似文献   

2.
报道11个预期有血管紧张素转化酶抑制活性的N-(4-甲氧羰基-4-邻苯二甲酰亚氨基丁酰基)-N-取代甘氨酸(VII1~9)、脯氨酸(VII10)和焦谷氨酸(VIl11)的合成和鉴定。所有上述化合物以及与VⅡ1~9相应的叔丁酯(VI1~9)均未见文献报道。药理初试结果显示,化合物VII8,VII9和VI10均有明显降压活性。  相似文献   

3.
报道4个N-(1-[1-乙氧羰基-3-(对甲)苯氨甲酰基]丙基甘氨酰}-N-取代甘氨酸(XI1~4)和5个1-[1-乙(或甲)氧羰基-3-(对甲)苯氨甲酰基]丙基-4-取代-1,4-哌嗪-2,5-二酮(XII1~5)共9个估计有血管紧张素转化酶抑制活性化合物的合成和鉴定。所有这些化合物及9个相应的酯(X1~9)均未见文献报道。药理初试结果,化合物XII2,XII5,XI4和XII1均有较强降压活性。  相似文献   

4.
酞丁安对映体合成及其抗单纯疱疹病毒活性评价   总被引:1,自引:0,他引:1  
酞丁安(3-酞酰亚胺-2-氧-正丁醛双缩氨硫脲,TDA)是药物研究所创制的抗病毒新药。为了研究其对映异构体(R),(S)-TDA对病毒活性及毒性是否有差异,并与消旋酞丁安(RS)-TDA的抗病毒活性及毒性进行比较,本文分别用已知构型的(R)-与(S)-丙氨酸为原料,通过缩合等6步反应,得到光学活性的(R)-,(S)-TDA,并与外消旋酞丁安比较其抗病毒活性及毒性。三者的抗单纯疱疹病毒活性与对细胞的毒性差别不大,说明消旋酞丁安临床使用是安全有效的。  相似文献   

5.
The influence of N -ethyl- and N -benzyl-1,2-diphenyl ethanolamines (compounds E and B, respectively) was examined on the spontaneously contracting rabbit jejunum and the rat uterus together with their influence on the contractions induced by some spasmogens in the guinea-pig ileum and oxytocics and CaCl2in the pregnant rat uterus. Both E and B inhibited the spontaneous contractions of the rabbit jejunum with ID50values of 0.13 and 0.03 μmol ml−1. Their inhibitory activities were not antagonized by α- or β-adrenoceptor blockers but significantly reversed by CaCl2(0.015 μmol ml−1). The compounds also antagonized nicotine, ACh-, histamine-, 5-HT- and CaCl2-induced contractions by 44–100%. Compound E seemed to be several times more potent than B in inhibiting the spontaneous uterine contractions with an ID50of (7 nmol ml−1). Their inhibitory effects were not antagonized by β2-adrenoceptor or H2-receptor blocking drugs. Both compounds (40 nmol ml−1) antagonized in a competitive manner CaCl2-induced contractions in the K+-depolarised uterus and PGE2and oxytocin-induced uterine contractions. The ID50values were in the range of 1.6–10.7 nmol ml−1. The results suggest that E and B compounds may be considered as putative L-Ca2+channel blockers with certain selectivities. The E compound seemed to be more selective against uterine L-Ca2+channels and the B compound against intestinal smooth muscles. Thus, the compounds may be of potential value in treatment of some colics, the irritant bowel syndrome, dysmenorrhoea and premature deliveries. 1999 Academic Press@p$hr  相似文献   

6.
The aim of the present study was to evaluate the possible mechanism of the vasorelaxant action of methanol extract from Laelia autumnalis (MELa) in isolated rat aortic rings, and to establish its antihypertensive activity in vivo. MELa (0.15→50 µg/mL) induced relaxation in aortic rings pre-contracted with KCl (80 mM), showing an IC50 value of 34.61 ± 1.41 µg/mL and Emax value of 85.0 ± 4.38% (in endothelium-intact rings) and an IC50 value of 45.11 ± 4.17 µg/mL and Emax value of 80.0 ± 12.1% (in endothelium-denuded rings). Serotonin (5-HT, 1 × 10− 4 M) provoked sustained contraction, which was markedly inhibited by MELa (0.15→50 µg/mL) in a concentration-dependent and endothelium-independent manner. Pretreatment with MELa (15, 46, 150, 300 and 1500 µg/mL) also inhibited contractile responses to norepinephrine (NE 1 × 10− 11 M to 1 × 10− 5.5 M). In endothelium-denuded rings, the vasorelaxant effect of MELa was reduced partially by ODQ (1 µM), but not by tetraethylammonium (5 µM), glibenclamide (10 µM), and 2-aminopyridine (100 µM). The extract also reduced NE-induced transient contraction in Ca2+-free solution, and inhibited contraction induced by increasing external calcium in Ca2+-free medium plus high KCl (80 mM). The antihypertensive effect of MELa was determined in spontaneously hypertensive rats (SHR). A single oral administration of the extract (100 mg/kg) exhibited a significant decrease in systolic and diastolic blood pressure and heart rate (p < 0.05) in SHR rats. Our results suggest that MELa induces relaxation in rat aortic rings through an endothelium-independent pathway, involving blockade of Ca2+ channels and a possible cGMP enhanced concentrations and also causes an antihypertensive effect.  相似文献   

7.
目的 探讨nNOS选择性抑制剂亚胺基烯丁基-L-鸟氨酸(L-VNIO)对心肌缺血再灌注(I/R)损伤的影响及机制。方法 构建SD大鼠离体心脏I/R模型和H9c2细胞缺氧/复氧(H/R)模型;nNOS抑制剂L-VNIO(10 μmol·L-1)持续给药整个再灌注或复氧过程。TTC染色测定心肌梗死面积;流式细胞术检测H9c2细胞凋亡率;Fluo-3/AM Ca2+荧光探针通过流式细胞仪检测H9c2细胞内Ca2+浓度;试剂盒法测定离体心脏灌流液乳酸脱氢酶(LDH)、丙二醛(MDA)水平以及H9c2细胞MDA水平和超氧化物歧化酶(SOD)活性;离体心脏提取肌浆网,试剂盒法检测肌浆网Ca2+-ATP酶(SERCA)活性,Western blotting检测肌浆网SERCA蛋白表达;Western blotting检测离体心脏中受磷蛋白(PLB)和兰尼碱受体2(RyR2)蛋白表达水平和磷酸化水平。结果 与I/R或H/R模型组相比,L-VNIO显著降低细胞凋亡率,减少心肌梗死面积,降低LDH、MDA水平,提高SOD活性,差异均有统计学意义(P<0.05);此外,与I/R或H/R模型组相比,L-VNIO组明显降低细胞内Ca2+超载,增高PLB磷酸化水平,降低RyR2磷酸化水平,增强SERCA活性(P<0.05)。结论 nNOS抑制剂L-VNIO可以减轻I/R损伤,机制与调节Ca2+转运相关蛋白而降低I/R引起的Ca2+超载相关。  相似文献   

8.
When NG-nitro-l-arginine, a nitric oxide synthase inhibitor, administration was started 5 min prior to shock induction in anesthetized dogs, a partial restoration was observed in endotoxin-induced shock and a complete recovery in platelet activating factor (PAF)-induced shock. When NG-nitro-l-arginine infusion was started 5 min after shock induction, no significant recovery was observed in endotoxin-induced shock and a complete recovery in PAF-induced shock. These data indicate that enhanced production of nitric oxide by vascular endothelial cells may contribute to endotoxin- or PAF-induced shock and also that some mediators including inducible nitric oxide synthase and/or cellular damage might be involved in endotoxin-induced shock.  相似文献   

9.
To assess the effects of the nitric oxide synthase inhibitor NG-Nitro-L-arginine on behavioural, biochemical and histological changes following global ischaemia, the Mongolian gerbil was used. Ischaemia was induced by bilateral carotid occlusion for 5 min. NG-Nitro-L-arginine was administered i.p. at either 1 or 10 mg/kg 30 min, 6, 24, and 48 h after surgery. 5 min bilateral carotid occluded animals were hyperactive 24, 48 and 72 h after surgery. NG-Nitro-L-arginine caused some attenuation in this hyperactivity. The activity of nitric oxide synthase was increased in the cerebellum, brain stem, striatum, cerebral cortex and hippocampus of 5 min bilateral carotoid occluded animals. NG-Nitro-L-arginine reversed the increase in nitric oxide synthase activity in all brain regions. Extensive neuronal death was observed in the CA1 layer of the hippocampus in 5 min bilateral carotid occluded animals 96 h after surgery. NG-Nitro-L-arginine significantly protected against the neuronal death of cells in the CA1 layer.  相似文献   

10.
Platelet [3H]-5HT uptake, [3H]-imipramine binding and endogenous 5HT levels were measured in healthy volunteers during short-term (20 days) administration of lithium, and following its withdrawal. The V max of [3H]-5HT uptake was significantly decreased during lithium treatment. Following lithium withdrawal, platelet [3H]-5HT uptake (V max) remained decreased and was followed by a pronounced rebound effect in some of the subjects for up to 3 months. The affinity constant (K m) of [3H-5HT uptake was not modified. Binding of tritiated imipramine during the same period and platelet 5HT levels measured till 14 days after withdrawal was not affected by lithium treatment. As lithium is devoid of in vitro effects on both 5HT uptake and imipramine binding, it is concluded that the effects of lithium on the 5HT transporter do not reflect a direct effect on the transporter complex. Our results indicate that lithium-induced changes at the level of 5HT uptake in platelets are not correlated with concomitant variations in platelet 5HT content and can be dissociated from modifications at the level of imipramine binding sites within the macromolecular complex of the 5HT transporter. Moreover, platelet 5HT uptake is apparently modulated by lithium, with a similar pattern in healthy volunteers and in manic-depressive patients.  相似文献   

11.
李全  沈旭  邵华武  谢毓元 《药学学报》1995,30(6):471-475
Seventeen compounds having the structure of 2,3-diacetoxy-1,4-bis(3′,5′- dioxo-N4′-substituted piperazinyl methyl)benzene were designed and synthesized based on chelation hypothesis. Their antitumor activities on P388 cells,Hep cells and SGC 7901 cells in vitro were tested. Preliminary results showed that compound 4e has potent antitumor effect against P388 cells and.Hep cells in vitro.  相似文献   

12.
褪黑激素(N-乙酰基-5-甲氧基色胺)的合成   总被引:5,自引:0,他引:5  
段传凤  杨依军 《药学学报》1996,31(3):182-185
This paper reports the synthesis of melatonin(N-acetyl-5-methoxytryptamine).The structure of all the compounds synthesized were characterized by elemental analysis,IR, MS and 1HNMR spectra.  相似文献   

13.
Rationale  Serotonin transporter (SERT) knockout (−/−) mice have an altered phenotype in adulthood, including high baseline anxiety and depressive-like behaviors, associated with increased baseline extracellular serotonin levels throughout life. Objectives  To examine the effects of increases in serotonin following the administration of the serotonin precursor 5-hydroxy-l-tryptophan (5-HTP) in SERT wild-type (+/+), heterozygous (+/−), and −/− mice. Results  5-HTP increased serotonin in all five brain areas examined with approximately 2- to 5-fold increases in SERT+/+ and +/− mice, and with greater 4.5- to 11.7-fold increases in SERT−/− mice. Behaviorally, 5-HTP induced exaggerated serotonin syndrome behaviors in SERT−/−, mice with similar effects in male and female mice. Studies suggest promiscuous serotonin uptake by the dopamine transporter (DAT) in SERT−/− mice, and here, the DAT blocker GBR 12909 enhanced 5-HTP-induced behaviors in SERT−/− mice. Physiologically, 5-HTP induced exaggerated temperature effects in SERT-deficient mice. The 5-HT1A antagonist WAY 100635 decreased 5-HTP-induced hypothermia in SERT+/+ and +/− mice with no effect in SERT−/− mice, whereas the 5-HT7 antagonist SB 269970 decreased this exaggerated response in SERT−/− mice only. WAY 100635 and SB 269970 together completely blocked 5-HTP-induced hypothermia in SERT+/− and −/− mice. Conclusions  These studies demonstrate that SERT−/− mice have exaggerated neurochemical, behavioral, and physiological responses to further increases in serotonin, and provide the first evidence of intact 5-HT7 receptor function in SERT−/− mice, with interesting interactions between 5-HT1A and 5-HT7 receptors. As roles for 5-HT7 receptors in anxiety and depression were recently established, the current findings have implications for understanding the high anxiety and depressive-like phenotype of SERT-deficient mice.  相似文献   

14.
辛军  胡璧  李政  糜福顺  沈瑜 《药学学报》1993,28(2):97-104
本文设计、合成了一类新型的放射增敏剂—吡啶丙烯酰氨基酸衍生物,并测定了对HeLa-Sa细胞的增敏作用和细胞毒性。3-吡啶丙烯酰甲基甘氨酸(3A)和4-吡啶丙烯酰甲基甘氨酸(4A)的主要作用分别为减小细胞存活曲线的肩宽和Do值。这类化合物,尤其是3A和4A,或其结构类似物,如果体内实验证明有明显增敏作用,将有重要的潜在临床应用价值。  相似文献   

15.
In vivo metabolism, nephrotoxicity and covalent binding to proteins were evaluated in male Fischer 344 rats that received [2,3-14C]-N-(3,5-dichlorophenyl)succinimide (14C-NDPS). Some animals were pretreated with the enzyme inducer phenobarbital (PB, 80 mg/kg per day, for 3 days, i.p. in saline) prior to receiving a non-nephrotoxic dose of 14C-NDPS (0.2 mmol/kg, i.p. in corn oil). Other rats were pretreated with the cytochrome P450 inhibitor 1-aminobenzotriazole (ABT, 100 mg/kg, 1 h prior to NDPS, i.p. in saline) before administration of a non-toxic or a toxic dose (0.2 or 0.6 mmol/kg, respectively, i.p. in corn oil) of 14C-NDPS. Non-pretreated animals received either dose of 14C-NDPS, but did not receive PB or ABT. All rats were sacrificed 6 h after administration of 14C-NDPS. Nephrotoxicity was monitored by measuring urine volume, urine protein concentrations, blood urea nitrogen levels, and kidney weights. The NDPS metabolic profile in tissue, blood, and urine was analyzed by HPLC. Covalent binding of 14C-NDPS-derived radioactivity to tissue proteins was also measured. Compared with non-pretreated rats, PB-pretreatment potentiated the toxicity of the non-toxic dose of 14C-NDPS. In contrast, ABT-pretreatment protected the rats against NDPS nephrotoxicity. The amount of N-(3,5-dichlorophenyl)-2-hydroxysuccinamic acid (2-NDHSA), an oxidative, nephrotoxic metabolite of NDPS, was elevated in kidney homogenates and urine by PB-pretreatment (0.2 mmol/mg NDPS). ABT pretreatment inhibited NDPS metabolism at both doses. Covalent binding of 14C-NDPS (0.2 mmol/kg)-derived radioactivity to renal and plasma proteins was higher in the PB-pretreated rats than in the non-pretreated animals. In contrast, ABT-pretreatment partially inhibited covalent binding at both doses of 14C-NDPS. Our results suggest that there is a relationship between oxidative metabolism of NDPS, covalent binding of an NDPS metabolite to renal proteins, and NDPS-induced nephrotoxicity in rats.  相似文献   

16.
用实验性胃溃疡模型研究了PG6E的抗溃疡作用,结果表明PG6E有抗胃酸分泌作用,而对胃肠运动无明显影响;PG6E在剂量为10~80μg·kg-1时,对无水乙醇型、盐酸型、消炎痛型、慢性醋酸型和幽门结扎型胃溃疡有明显保护作用,并能显著减少幽门结扎大鼠的胃液体积、胃酸分泌、胃蛋白酶活性和DNA含量。小鼠poPG6E30~60μg·kg-1,3d后粘膜氨基己糖含量显著增加。研究结果提示PG6E能抑制对胃粘膜的攻击性因素,增加保护性因素的作用,可望成为一种新型抗胃溃疡药。  相似文献   

17.
N-Methyl-D-aspartate (NMDA) receptor antagonists, acting in the spinal cord, are analgesic. However, the clinical utility of these antagonists is diminished by their adverse effects on cognition and behavior. To facilitate the development of spinal cord-selective NMDA receptor antagonists, we characterized ligand interactions at NMDA receptors in spinal cord of normal rats and rats with a chronic peripheral neuropathy. NMDA receptors in spinal cord were distinguished from those in cerebral cortex on the basis of differences in the potencies of competitive and noncompetitive antagonists and on the basis of differences in their response to spermidine. D(-)-2-Amino-5-phosphonopentanoic acid (AP-5) and (+)-(1-hydroxy-3-aminopyrrolidine-2-one) (HA-966) were more potent in inhibiting NMDA-dependent [3H]TCP binding in spinal cord while, conversely, MK-801 was more potent in inhibiting [3H]TCP binding to NMDA receptors in cerebral cortex. Spermidine increased [3H]TCP binding to NMDA receptors in cerebral cortex (39 ± 8%) but not spinal cord (2 ± 1%). Based on these properties, NMDA receptors in spinal cord more closely resembled those in cerebellum than those in cerebral cortex. Generation of a chronic neuropathy had no effect on the density of NMDA receptors in lumbar spinal cord. There were also no major changes in the potencies of competitive antagonists or channel blocking ligands, although there was a trend for kynurenic acid and -CPP to be more potent in the spinal cords of neuropathic animals. These findings indicate that, in both normal and neuropathic pain states, NMDA receptors in spinal cord can be distinguished pharmacologically from those in cerebral cortex. These findings underscore the feasibility of developing spinal cord-selective NMDA receptor antagonists as novel analgesics.  相似文献   

18.
Metapramine, a pharmacological compound with antidepressant activity in humans, was tested for possible antiglutamatergic activity, in vitro. We investigated the effects of metapramine on the N-methyl- -aspartic acid (NMDA) receptor complex, by determining whether this compound would interfere with the binding of [3H]N-[1-(2-thienyl)cyclohexyl]-3,4-piperidine ([3H]TCP) to rat cortical membranes in the presence of either glycine NMDA, or both. Metapramine in the micromolar range inhibited the binding of [3H]TCP in the presence of both NMDA and glycine ( 50 = 1.4 ± 0.2 μM). That very similar affinities were observed when either NMDA or glycine was present suggests that metapramine exerted a direct action at the PCP site. The affinity of metapramine for this site was about 25 and 350 times lower than that of PCP and MK-801, respectively. Metapramine inhibited the NMDA-evoked increase in guanosine 3′,5′-cyclic monophosphate (cGMP) levels of neonatal rat cerebellar slices ( 50 = 13 μM). These results suggest that metapramine is a low-affinity antagonist of the NMDA receptor complex channel. This paper discusses the potential application of metapramine to the treatment of diseases linked to excessive stimulation of glutamatergic NMDA receptors. © 1997 Elsevier Science Ltd. All rights reserved.  相似文献   

19.
Purpose The aim of the study is to analyze the effect of varying the degree of unsaturation in synthesized N4,N9-dioctadecanoyl spermines on DNA condensation and then to compare their transfection efficiency in cell culture. Methods The N4,N9-di-C18 lipopolyamines—saturated (stearoyl), C9-cis- (oleoyl), and C9,12-di-cis- (linoleoyl)—were synthesized from the naturally occurring polyamine spermine. The ability of these novel compounds to condense DNA and form nanoparticles was studied using ethidium bromide fluorescence quenching and nanoparticle characterization techniques. Transfection efficiency was studied in several primary skin cells (FEK4, FCP4, FCP5, FCP7, and FCP8) and in an immortalized cancer cell line (HtTA) and was compared with the commercially available nonliposomal transfection formulation Transfectam? (dioctadecylamidoglycyl spermine), which also contains two saturated C18 lipid chains. Results N4,N9-Dilinoleoyl spermine (C18, di-cis-9,12) is efficient at circular plasmid DNA (pEGFP) condensation and gives the most effective transfection in a series of primary skin cells and cancer cell lines at low charge ratios of 5.5 (± ammonium/phosphate). Conclusions The dienoic fatty acyl spermine conjugate N4,N9-dilinoleoyl spermine efficiently condenses DNA and achieves the highest transfection levels among the studied lipopolyamines in cultured cells.  相似文献   

20.
Lanthanide nanoparticles and nanorods have been widely used for diagnostic and therapeutic applications in biomedical nanotechnology due to their fluorescence and pro-angiogenic properties to endothelial cells, respectively. Recently, we have demonstrated that europium (III) hydroxide [EuIII(OH)3] nanorods, synthesized by the microwave technique and characterized by several physico-chemical techniques, can be used as pro-angiogenic agents which introduce future therapeutic treatment strategies for severe ischemic heart/limb disease, and peripheral ischemic disease. The toxicity of these inorganic nanorods to endothelial cells was supported by several in vitro assays. To determine the in vivo toxicity, these nanorods were administered to mice through intraperitoneal injection (IP) everyday over a period of seven days in a dose dependent (1.25 to 125 mg kg− 1 day− 1) and time dependent manner (8–60 days). Bio-distribution of europium elements in different organs was analyzed by inductively coupled plasma mass spectrometry (ICPMS). Short-term (S-T) and long-term (L-T) toxicity studies (mice euthanized on days 8 and 60 for S-T and L-T, respectively) show normal blood hematology and serum clinical chemistry with the exception of a slight elevation of liver enzymes. Histological examination of nanorod-treated vital organs (liver, kidney, spleen and lungs) showed no or only mild histological changes that indicate mild toxicity at the higher dose of nanorods.  相似文献   

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