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1.
左旋千金藤啶碱对不同脑区DA更新率的影响   总被引:1,自引:0,他引:1  
贺毓芳  黄开星 《生理学报》1995,47(5):429-434
应用HPLC-ECD测定DA更新率(DOPAC/DA),证明(-)SPD对黑质-纹状体、中脑-边缘系统、下丘脑-垂体DA神经系统的DA含量影响不明显,却显著增加DOPAC含量,并显著加强这些脑区的DA更新率,这可能是通过末梢的DA自身受体实现的。但(-)SPD既不显著影响中脑-前额叶和中脑-扣带回的DA含量,也不影响其中DOPAC含量,表明它不影响这些脑区DA更新率。这可能是由于皮层DA系统神经末  相似文献   

2.
The syntheses of (±) 2α,6β-diethyl-7α-ethynyl-3α-(p-hydroxyphenyl)-trans-bicyclo[4.3.0]nonan-7β-ol (8), (±)2β,6β-diethyl-7α-ethynyl-3β-(p-methoxyphenyl)-trans-bicyclo[4.3.0]nonan-7β-ol (12) and (±) 2α,6β-diethyl-7α-ethynyl-3β-(p-hydroxyphenyl)-trans-bicyclo[4.3.0]nonan-7β-ol (18) and their derivatives, which are essentially B-seco-steroids having cis-anti-trans, cis-syn-trans and trans-anti-trans geometries have been carried out. A study of their antiimplantation activities (AI) and receptor binding affinities (RBA) show that trans-anti-trans compounds are biologically most potent, followed by the corresponding cis-anti-trans and cis-syn-trans compounds. The most potent compound 18 is active at 1 mg/kg in rats. Introduction of 7α-ethynyl group increases their AI activity; however, no significant effect on their RBA is observed.  相似文献   

3.
《Insect Biochemistry》1987,17(1):21-28
Rust-red wild and black mutant strains of the red flour beetle, Tribolium castaneum, were used to investigate temporal patterns of catecholamine and β-alanine content during sclerotization and pigmentation of adult cuticle and to relate these patterns to corresponding changes in cuticle resistance to puncture. Rust-red elytral cuticle sclerotized more rapidly than black cuticle until 6 days after adult eclosion when both became equal in puncture resistance. The cuticular concentrations of N-β-alanyldopamine (NBAD), β-alanine and 3,4-dihydroxyphenylacetic acid (DOPAC) increased more rapidly in the rust-red strain than in the black strain during the first 7 days following adult eclosion. Conversely, cuticular dopamine increased more rapidly in black than in the red strain. Thus the rust-red pigmentation and rapid sclerotization appear to be related to the availability of β-alanine, N-β-alanyldopamine and DOPAC. Melanization was prevented and rust-red pigmentation induced by injections of β-alanine or NBAD into newly ecdysed black mutant beetles. Crosses of the two strains generally had intermediate levels of cuticular dopamine and β-alanine, but the NBAD levels were similar to those of the rust-red strain. Dopamine, NBAD and DOPAC levels became similar in both black and rust-red strains about 6 days after adult ecdysis as did resistance to puncture. Therefore, dopamine appears to be directed initially into the melanin pathway in black adults due to a temporary lack of N-acylation with β-alanine. After the melanization phase, dopamine is metabolized to sclerotization precursors eventually resulting in normal physical properties of the exoskeleton.  相似文献   

4.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) hydrochloride injected s.c. at 20 mg/kg once daily for four days resulted in marked depletion of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in mouse striatum one week after the last dose. Pretreatment with MD 240928, (R)-[4-((3-chlorophenyl)-methoxy)phenyl]-5-[(methylamino)methyl]-2- oxazolidinone methanesulfonate, prevented the depletion of striatal dopamine, DOPAC and HVA, whereas pretreatment with harmaline did not. MD 240928 selectively inhibited type B not type A monoamine oxidase (MAO), whereas harmaline selectively inhibited type A MAO in mouse striatum. Acutely after injection of harmaline, DOPAC and HVA concentrations were decreased in mouse striatum; these changes were not produced by MD 240928. The acute changes in dopamine metabolites reveal that MAO-A not MAO-B is responsible for the oxidation of dopamine in mouse striatum. Protection against the neurotoxic effects of MPTP by MD 240928 but not by harmaline indicates that prevention of dopamine oxidation is not the mechanism of the protective effect; instead the protection probably is due to prevention of MPTP metabolism by MAO-B, this metabolism having been shown to occur by other workers. The results with these reversible, competitive inhibitors of the two types of MAO are in agreement with previously reported results from studies using irreversible inhibitors of MAO.  相似文献   

5.
S A Persson 《Life sciences》1977,20(7):1199-1205
Administration of d-lysergic acid diethylamide (LSD) and its analogue 2-bromo lysergic acid diethylamide (BOL) resulted in a shortlasting increase of 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the rat striatum. BOL was more potent than LSD in the dose range 0.5–4.0 mg/kg. Since there was a concomitant increase in the striatal invivo tyrosine hydroxylation as measured by DOPA accumulation after decarboxylase inhibition, our findings suggest that LSD and BOL increase the impulse flow in the nigro-neostriatal pathway probably by central dopamine (DA) receptor antagonism. However, 4 hrs after LSD the DOPAC level was decreased, while the DOPA accumulation was not. Thus the effect of LSD on the dopaminergic system appears not to be limited to a pure receptor antagonism. The possibility also exists that the effect of LSD on the nigro-neostriatal DA pathway is secondary to its effect on the central 5-hydroxytryptaminergic system.  相似文献   

6.
As part of a program to synthesize the ceramide trisaccharide (1) related to Fabry's disease, methyl 4-O-(4-O-α-d-galactopyranosyl-β-d-galactopyranosyl)-β-d-glucopyranoside (12) was prepared. Methyl β-lactoside (2) was converted into methyl 4-O-(4,6-O-benzylidene-β-d-galactopyranosyl)-β-d-glucopyranoside (4). Methyl 2,3,6-tri-O-benzoyl-4-O-(2,3,6-tri-O-benzoyl-β-d-galactopyranosyl)-β-d-glucopyranoside (7) was synthesized from 4 through the intermediates methyl 2,3,6-tri-O-benzoyl-4-O-(4,6-O-benzylidene-2,3-di-O-benzoyl-β-d-galactopyranosyl)-β-d-glucopyranoside (5) and methyl 2,3,6-tri-O-benzoyl-4-O-(2,3-di-O-benzoyl-β-d-galactopyranosyl)-β-d-glucopyranoside (6). The halide-catalyzed condensation of 7 with 2,3,4,6-tetra-O-benzyl-d-galactopyranosyl bromide (8) gave methyl 2,3,6-tri-O-benzoyl-4-O-[2,3,6-tri-O-benzoyl-4-O-(2,3,4,6-tetra-O-benzyl-α-d-galactopyranosyl)- β-d-galactopyranosyl]-β-d-glucopyranoside (10). Stepwise deprotection of 10 led to 12, the methyl β-glycoside of the trisaccharide related to Fabry's disease.  相似文献   

7.
The in vitro reaction of bacteriophage T7-DNA with the radioactive diastereomeric benzo(a)pyrene-diol-epoxides, (±) [3H9, 3H10]-7β,8α-dihydroxy-9α,10β-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, and (±) [3H9, 3H10]-7β,8α-dihydroxy-9β,19β-epoxy-7,8,9,10-tetrahydrobenzo(1)pyrene, was investigated. Chromatographic analysis of digests of the DNA allowed the distinction of characteristic deoxynucleoside adduct peaks for the two benzo(a)pyrene-diol-epoxides. Our results, together with data from the literature, allow the identification of these adducts as mostly N2-(10-7β,8α,9α-trihydroxy-7,8,9,10-tetrahydrobenzo(a)pyreney1)deoxyguanosine and N2-(10-7β,8α,9β-trihydroxy-7,8,9,10-tetrahydrobenzo(a)pyreney1)deoxyguanosine, respectively. DNA-benzo(a)pyrene adducts with the same chromatographic properties were formed in mouse embryo fibroblasts upon treatment with benzo(a)pyrene.  相似文献   

8.
Ascorbic acid, at concentrations below that normally present in the brain, inhibited the dopamine-sensitive adenylate cyclase invitro. Ascorbate had no effect on the norepinephrine-sensitive adenylate cyclase. To study the invivo effect of ascorbic acid on central dopaminergic systems, mice (C57 B1/6J) were injected with pharmacological doses (2 g/kg) of ascorbate, which produced a significant elevation in brain ascorbate concentration. Injecting the mice with ascorbate (2 g/kg) blocked the amphetamine-induced (15 mg/kg) increase in stereotype behavior which has been reported to be mediated by dopaminergic neural systems. Ascorbate had no effect on the amphetamine-induced locomotor activity thought to be mediated by norepinephrine systems. Ascorbate (1 g/kg) attenuated apmorphine-induced hypothermia in this same strain of mice. This demonstrates the specific neurochemical, physiological, and behavioral alterations in dopaminergic systems produced by ascorbic acid and suggests possible therapeutic uses for ascorbate in conditions involving functional dopamine excess.  相似文献   

9.
Neuronal activity was recorded from the ventral tegmental area (VTA) of immobilized, locally anesthetized rats on the day immediately following long-term treatment (twice daily for 6 consecutive days) with saline, 1.0 or 5.0 mg/kg d-amphetamine (d-AMPH). Each rat was challenged intravenously with d-AMPH (beginning with 0.0625 mg/kg) or with 0.005 mg/kg apomorphine. Treatment with d-AMPH significantly reduced the ability of this drug to inhibit VTA activity. In fact, nearly half of the neurons in the high-dose treatment group were excited by d-AMPH, whereas only 20% of control neurons showed this response. Moreover, apomorphine routinely accelerated firing rate in the VTA following treatment with 5.0 mg/kg d-AMPH but this response was never observed in control neurons, not even in those that were excited by d-AMPH. Thus, tolerance appears to develop to the ability of dopamine agonists to inhibit VTA activity and this effect may be mediated, at least in part, by a subsensitivity of inhibitory dopamine autoreceptors.  相似文献   

10.
Using high resolution capillary gas chromatography, we have unequivocally separated two possible (6- and 7-)mono-O-methylated tetrahydroisoquinoline metabolites in rat brain after acute intraventricular administration of salsolinol, a cyclized dopamine/acetaldehyde derivative. 7-O-Methylsalsolinol (salsoline) constituted 94–98% of the two isomers in five brain regions examined. These results confirm the report by Bail etal. that salsolinol is largely O-methylated invivo (presumably by brain catechol-O-methyl transferase) on the hydroxyl situated “para” in the parent dopamine molecule. In comparison, dopamine itself, administered intraventricularly to pargyline-pretreated rats, was O-methylated exclusively on the “meta” hydroxyl group.  相似文献   

11.
SELECTIVE INCREASE OF BRAIN DOPAMINE SYNTHESIS BY SULPIRIDE   总被引:4,自引:3,他引:1  
—Sulpiride (5–200 mg/kg) increases brain HVA and DOPAC levels, causes no change in dopamine concentration, does not interfere with the outflow of HVA from the CNS and enhances the disappearance of brain dopamine after inhibition of tyrosine hydroxylase. The compound influences neither 5-HT nor NE metabolism. The central action of sulpiride differs from that of classic neuroleptics in that this drug stimulates dopamine turnover without producing catalepsy.  相似文献   

12.
The compound 6-Methoxy-1, 2, 3, 4-tetrahydro-β-carboline (6-MeO-THβC) belonging to the group of hallucinogenic β-carbolines has been found to alter various aspects of serotonergic transmission in the brain. The action of 6-MeO-THβC on the newly identified 5-HT system of bovine retina was studied in vitro. The drug inhibited the high affinity uptake of [3H] 5-HT in a competitive manner and had no evident effect on the uptake of dopamine or GABA. In addition the compound increased the potassium evoked release of 5-HT from retina. Endogenous β-carbolines have been proposed to be involved in the modulation of serotonergic activity in the brain and a similar action is proposed in the retina. In addition these findings raise the possibility of retinal 5-HT system as a site of action for β-carbolines and similar hallucinogenic drugs.  相似文献   

13.
A series of 5-, 6-, 7- and 8-aza analogues of 3-aryl-4-hydroxyquinolin-2(1H)-one was synthesized and assayed as NMDA/glycine receptor antagonists. The in vitro potency of these antagonists was determined by displacement of the glycine site radioligand [(3)H]5,7-dicholorokynurenic acid ([(3)H]DCKA) in rat brain cortical membranes. Selected compounds were also tested for functional antagonism using electrophysiological assays in Xenopus oocytes expressing cloned NMDA receptor (NR) 1A/2C subunits. Among the 5-, 6-, 7-, and 8-aza-3-aryl-4-hydroxyquinoline-2(1H)-ones investigated, 5-aza-7-chloro-4-hydroxy-3-(3-phenoxyphenyl)quinolin-2-(1H)-one (13i) is the most potent antagonist, having an IC(50) value of 110 nM in [(3)H]DCKA binding and a K(b) of 11 nM in the electrophysiology assay. Compound 13i is also an active anticonvulsant when administered systemically in the mouse maximum electroshock-induced seizure test (ED(50)=2.3mg/kg, IP).  相似文献   

14.
Piribedil, (1–2″-pyrimidyl)-4-piperonyl piperazine), an agent proposed for the treatment of Parkinson's disease, was found to increase acetylcholine levels in the rat striatum and diencephalon but not in the mesencephalon, cerebellum or hemispheres. The effect was most marked in the striatum (greater than 100%) and long-lasting (at least 8 hours after a single administration of 60 mg/kg i.p.). Striatal choline levels were also increased by piribedil but did not parallel at all times and doses the effect on acetylcholine. Furthermore, choline levels were increased in all brain regions except the hemispheres. Striatal choline acetyltransferase and acetylcholinesterase were not affected by in vitro or in vivo treatment with even high doses of piribedil. α-Methyl-p-tyrosine was ineffective in blocking piribedil while pimozide, a blocker of dopamine receptors, completely antagonized the action of piribedil on striatal acetylcholine. It is concluded that piribedil produced the increase in striatal acetylcholine by directly stimulating dopamine receptors.  相似文献   

15.
Both the methyl ester of β-carboline-3-carboxylic acid and the 6, 7-dimethoxy-4-ethyl derivative of this compound are potent convulsants in rodents, while the ethyl ester of β-carboline-3-carboxylic acid does not cause convulsions, even when administered at very high doses. The rate of degradation of these compounds by rat plasma (in vitro) parallels their potencies as convulsants. In contrast, 3-carboethoxy-β-carboline was found to potently elicit tonic and clonic convulsions in the squirrel monkey (Saimiri sciureus). Furthermore, the rate of degradation of 3-carboethoxy-β-carboline in monkey plasma (in vitro) is negligible compared with rats. No significant differences were observed in either the potency or efficacy of GABA to inhibit [3H] β-carboethoxy-β-carboline binding in rat and monkey brain. These data strongly suggest that pharmacokinetic, as well as pharmacodynamic, factors may determine the pharmacologic profile of these β-carboline-3-carboxylic acid esters.  相似文献   

16.
Abstract: The effects of intracerebroventricular administration of the 5-hydroxytryptamine (5-HT)1A agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.1 pmol) on adrenocortical and neurochemical responses to stress were examined in conscious male rats. The following stress paradigms were used: acoustic stimulation (105 dB for 2 min); footshock (0.2 mA, five shocks over 5 min); conditioned fear (animals placed in a footshock chamber for 5 min, 24 h after footshock); restraint (5 min); intraperitoneal (i.p.) injection of recombinant human interleukin-1α (rHu-IL-1α, 20 µg/kg); and injection of cocaine hydrochloride (20 mg/kg, i.p.). As previously shown, 8-OH-DPAT was able to attenuate the adrenocortical response to acoustic stress, conditioned fear, rHu-IL-1α, and cocaine administration. Cocaine decreased 5-hydroxyindoleacetic acid (5-HIAA)/5-HT and dihydroxyphenylacetic acid/dopamine (DOPAC/DA) ratios and norepinephrine (NE) concentration in the prefrontal cortex, hypothalamus, and brainstem in all experiments, and 8-OH-DPAT reversed the changes in DOPAC/DA ratio without affecting 5-HIAA/5-HT ratios or NE content. 8-OH-DPAT alone had no effect on these parameters, although it decreased NE content in the prefrontal cortex in several experiments, and in the brainstem in one experiment. Significant decreases in NE content were observed in some brain regions following some of the stressors, but these changes were not generally affected by 8-OH-DPAT. Increases in the 5-HIAA/5-HT and DOPAC/DA ratios were also observed in some brain sites following some stressors, but these changes were not affected by 8-OH-DPAT except in the case of the increased 5-HIAA/5-HT ratio in the prefrontal cortex following the conditioned fear response. These results indicate that although 8-OH-DPAT is able to decrease plasma corticosterone responses following acoustic stress, conditioned fear, rHu-IL-1α, and cocaine administration, these effects do not appear to be related to an action of the 5-HT1A agonist on biogenic amine metabolism. This observation indicates that the predominant effect of 8-OH-DPAT on adrenocortical responses is mediated at postsynaptic sites not involved in the regulation of cerebral biogenic amine metabolism.  相似文献   

17.
Beginning on the fifth day of gestation, rats were administered 1 or 3 mg/kg of d-amphetamine sulfate s.c. twice daily until term. The administration of d-amphetamine caused a dose-related increase in pup mortality. However, the increase in pup death could not be correlated with any gross pathological signs. The surviving 3 mg/kg amphetamine pups were analyzed for changes in motor behavior and brain biogenic amine levels. It was found that the amphetamine offspring showed a marked reduction in the ability to habituate to new surroundings, and this effect persisted for at least three months after birth. On day 35, brain levels of norepinephrine in the “amphetamine” offspring were decreased 21 percent. On day 84, in the “amphetamine offspring,” norepinephrine levels were reduced 18 percent in both the diencephalon and brainstem; dopamine levels were reduced 21 percent in the brainstem compared to control offspring.  相似文献   

18.
Both the 5α, 6α- and 5β, 6β-dichloromethylene adducts (2a and 2b) of 3β-acetoxy-5-androsten-17-one (1) are produced when the latter is exposed to dichlorocarbene generated from chloroform and base by Phase Transfer Catalysis using ultrasound as a means of agitation. The 1H NMR substituent effects of 5α, 6α- and 5β, 6β-dichloromethylene on the angular methyl groups (Zürcher values) are given. The 13C NMR spectra for both compounds are presented and discussed.  相似文献   

19.
Caudate catecholamine release was monitored by bilateral invivo electrochemical electrodes in male Sprague-Dawley rats trained to circle for sucrose/water reward. Baseline release of dopamine was equal from both sides of caudate. When reinforced circling began, 33 ± 4 percent greater catechol release occured from the caudate contralateral to the circling direction. As turning subsided, differential release returned to basal levels. Further evidence that the catecholamine metabolism was affected by turning was obtained by direct measurement of caudate dopamine and DOPAC at selected time points. Concentration data showed relative increases in dopamine and DOPAC in the contralateral caudate. These data provide evidence that dopamine is released asymmetrically from caudate in unlesioned rats during voluntary behavior.  相似文献   

20.
Brain-corpora cardiaca-corpora allata complexes from the tobacco budworm Heliothis virescens produce both radiolabelled methyl (2E, 6E, 10Z)-10,11-epoxy-3, 11-dimethyl-7-ethyl-2, 6-tridecadienoate (JH I) and methyl (2E, 6E, 10Z)-10, 11-epoxy-3, 7, 11-trimethyl-2, 6-tridecadienoate (JH II) when cultured in medium containing L-[methyl14C] methionine or sodium [1−14C] propionate. Degradative studies of the hormones derived from propionate show the specific incorporation of the latter into the homo-isoprenoid portions of these compounds.  相似文献   

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