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1.
J Pharmacol Exp Ther ; 347(1): 57-68, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23863695

RESUMO

Dopaminergic, serotonergic, and adrenergic receptors are targets for therapeutic actions in schizophrenia. Dopamine D2 receptor partial agonists such as aripiprazole represent a treatment option for patients with this severe disorder. The ineffectiveness of terguride, another D2 receptor partial agonist, in treating schizophrenia was recently attributed to its considerably high intrinsic activity at D2 receptors. In this study, we used functional assays for recombinant D2 receptors and native 5-hydroxytryptamine 2A (5-HT2A), α2C-adrenergic, and histamine H1 receptors to compare the pharmacological properties of terguride and three of its halogenated derivatives (2-chloro-, 2-bromo-, 2-iodoterguride) with those of aripiprazole. Subsequently, we studied the antidopaminergic effects of 2-bromoterguride using amphetamine-induced locomotion (AIL). Its influence on spontaneous behavior was tested in the open field. Extrapyramidal side effect (EPS) liability was evaluated by catalepsy test. In a guanosine 5'-O-(3-[(35)S]thio)triphosphate ([(35)S]GTPγS) binding assay, 2-chloro-, 2-bromo-, and 2-iodoterguride produced intrinsic activities at human D2short (hD2S) receptors that were half as high as the intrinsic activity for terguride; aripiprazole lacked agonist activity. 2-Bromoterguride and aripiprazole activated D2S receptor-mediated inhibition of cAMP accumulation to the same extent; intrinsic activity was half as high as that of terguride. All compounds tested behaved as antagonists at human D2long/Gαo (hD2L/Gαo) receptors. Compared with aripiprazole, terguride and its derivatives displayed higher affinity at porcine 5-HT2A receptors and α2C-adrenoceptors and lower affinity at H1 receptors. 2-Bromoterguride inhibited AIL and did not induce catalepsy in rats. Because of its in vitro and in vivo properties, 2-bromoterguride may be a strong candidate for the treatment of schizophrenia with a lower risk to induce EPS.


Assuntos
Antipsicóticos/administração & dosagem , Antipsicóticos/metabolismo , Agonistas de Dopamina/metabolismo , Lisurida/análogos & derivados , Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2C de Serotonina/metabolismo , Receptores de Dopamina D2/metabolismo , Animais , Células CHO , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/metabolismo , Cricetinae , Cricetulus , Agonistas de Dopamina/química , Agonistas de Dopamina/farmacologia , Células HEK293 , Humanos , Lisurida/química , Lisurida/metabolismo , Lisurida/farmacologia , Masculino , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Técnicas de Cultura de Órgãos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de Dopamina D2/agonistas , Suínos
2.
J Pharmacol Exp Ther ; 340(2): 369-76, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22049464

RESUMO

Serotonin (5-hydroxytryptamine; 5-HT) is involved in heart valve tissue fibrosis, pulmonary arterial fibrosis, and pulmonary hypertension. We aimed at characterizing the antiserotonergic properties of the ergot alkaloid derivative terguride [1,1-diethyl-3-(6-methyl-8α-ergolinyl)urea] by using functional receptor assays and valvular interstitial cell culture. Terguride showed no vasoconstrictor effect in porcine coronary arteries (5-HT(2A) receptor bioassay) and no relaxant effect in porcine pulmonary arteries (5-HT(2B) receptor bioassay). Terguride behaved as a potent antagonist at 5-HT(2A) receptors (noncompetitive antagonist parameter pD'2 9.43) and 5-HT(2B) receptors (apparent pA2 8.87). Metabolites of terguride (N″-monodeethylterguride and 6-norterguride) lacked agonism at both sites. N″-monodeethylterguride and 6-norterguride were surmountable antagonists at 5-HT(2A) receptors (pA2 7.82 and 7.85, respectively) and 5-HT(2B) receptors (pA2 7.30 and 7.11, respectively). Kinetic studies on the effects of terguride in pulmonary arteries showed that the rate to reach drug-receptor equilibrium for terguride was fast. Washout experiments showed that terguride easily disappeared from the receptor biophase. Pretreatment with terguride inhibited 5-HT-induced amplification of ADP-stimulated human platelet aggregation (IC50 16 nM). In porcine valvular interstitial cells, 5-HT-induced activation of extracellular signal-regulated kinase (ERK) 1/2, an initiator of cellular proliferation and activity, was blocked by terguride as shown by Western blotting. In these cells, the stimulatory effect of 5-HT on [³H]proline incorporation (index of extracellular matrix collagen) was blocked by terguride. Because of the inhibition of both 5-HT(2A) and 5-HT(2B) receptors, platelet aggregation, and cellular proliferation and activity (ERK1/2 phosphorylation and collagen production) terguride may have therapeutic potential in the treatment of fibrotic disorders.


Assuntos
Vasos Sanguíneos/efeitos dos fármacos , Valvas Cardíacas/citologia , Lisurida/análogos & derivados , Agregação Plaquetária/efeitos dos fármacos , Antagonistas do Receptor 5-HT2 de Serotonina/farmacologia , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Difosfato de Adenosina/farmacologia , Animais , Valva Aórtica/citologia , Vasos Sanguíneos/fisiologia , Células Cultivadas , Colágeno/biossíntese , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/fisiologia , Relação Dose-Resposta a Droga , Humanos , Técnicas In Vitro , Concentração Inibidora 50 , Ketanserina/farmacologia , Cinética , Lisurida/metabolismo , Lisurida/farmacologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Valva Mitral/citologia , Fosforilação/efeitos dos fármacos , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/fisiologia , Serotonina/farmacologia , Antagonistas do Receptor 5-HT2 de Serotonina/metabolismo , Sus scrofa , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia
3.
Science ; 375(6579): 403-411, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-35084960

RESUMO

Drugs that target the human serotonin 2A receptor (5-HT2AR) are used to treat neuropsychiatric diseases; however, many have hallucinogenic effects, hampering their use. Here, we present structures of 5-HT2AR complexed with the psychedelic drugs psilocin (the active metabolite of psilocybin) and d-lysergic acid diethylamide (LSD), as well as the endogenous neurotransmitter serotonin and the nonhallucinogenic psychedelic analog lisuride. Serotonin and psilocin display a second binding mode in addition to the canonical mode, which enabled the design of the psychedelic IHCH-7113 (a substructure of antipsychotic lumateperone) and several 5-HT2AR ß-arrestin-biased agonists that displayed antidepressant-like activity in mice but without hallucinogenic effects. The 5-HT2AR complex structures presented herein and the resulting insights provide a solid foundation for the structure-based design of safe and effective nonhallucinogenic psychedelic analogs with therapeutic effects.


Assuntos
Antidepressivos/farmacologia , Desenho de Fármacos , Alucinógenos/química , Alucinógenos/farmacologia , Receptor 5-HT2A de Serotonina/química , Animais , Antidepressivos/química , Antidepressivos/metabolismo , Arrestina/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Alucinações/induzido quimicamente , Alucinógenos/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/química , Humanos , Ligantes , Lisurida/química , Lisurida/metabolismo , Dietilamida do Ácido Lisérgico/química , Dietilamida do Ácido Lisérgico/metabolismo , Camundongos , Conformação Proteica , Psilocibina/análogos & derivados , Psilocibina/química , Psilocibina/metabolismo , Receptor 5-HT2A de Serotonina/metabolismo , Serotonina/química , Serotonina/metabolismo , Transdução de Sinais , Relação Estrutura-Atividade
4.
Eur J Pharmacol ; 515(1-3): 10-9, 2005 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-15894311

RESUMO

Aripiprazole is the first clinically approved atypical antipsychotic agent having dopamine D2 receptor partial agonist activities. To evaluate aripiprazole's agonist and antagonist properties, we established a Chinese hamster ovary cell line expressing high and low densities of the long and short isoforms of human dopamine D2 receptors, then compared its properties with 7-{3-[4-(2,3-dimethylphenyl)piperazinyl]propoxy}-2(1H)-quinolinone (OPC-4392), S(-)-3-(3-hydroxyphenyl)-N-n-propylpiperidine ((-)-3-PPP), and terguride (other partial agonists) using forskolin-stimulated cAMP accumulation as an index. In cells expressing high receptor densities, all partial agonists predominantly behaved as agonists. However, in cells expressing low receptor densities, the partial agonists showed significantly lower maximal effects than dopamine. Aripiprazole showed the lowest intrinsic activities. In addition, all compounds blocked the action of dopamine with a maximum effect equal to that of each compound alone. Aripiprazole's low intrinsic activities may account for the clinical finding that, unlike the other partial agonists, it is substantially active against both positive and negative symptoms of schizophrenia.


Assuntos
Lisurida/análogos & derivados , Piperazinas/metabolismo , Quinolonas/metabolismo , Receptores de Dopamina D2/metabolismo , Animais , Antipsicóticos/metabolismo , Antipsicóticos/farmacologia , Aripiprazol , Ligação Competitiva/efeitos dos fármacos , Células CHO , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Colforsina/farmacologia , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , DNA Complementar/genética , Dopamina/metabolismo , Dopamina/farmacologia , Agonistas de Dopamina/metabolismo , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/metabolismo , Antagonistas de Dopamina/farmacologia , Haloperidol/metabolismo , Haloperidol/farmacologia , Humanos , Lisurida/metabolismo , Lisurida/farmacologia , Piperazinas/farmacologia , Piperidinas/metabolismo , Piperidinas/farmacologia , Quinolonas/farmacologia , Racloprida/metabolismo , Ensaio Radioligante , Receptores de Dopamina D2/genética , Risperidona/metabolismo , Risperidona/farmacologia , Transfecção , Trítio
5.
J Cereb Blood Flow Metab ; 11(6): 914-25, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1834685

RESUMO

The in vivo kinetic analysis of dopamine D2 receptors was obtained in baboon brain using positron emission tomography (PET) and [76Br]bromolisuride [( 76Br]BLIS) as radioligand. An injection of a trace amount of [76Br]BLIS was followed 3 h later by an injection of a mixture of [76Br]BLIS and BLIS in the same syringe (coinjection experiment). A third injection performed at 6 h was either an excess of unlabeled ligand (displacement experiment) or a second coinjection. This protocol allowed us to evaluate in the striatum of each animal and after a single experiment the quantity of available receptors (B'max) and the kinetic parameters including the association and dissociation rate constants (k + 1VR and k-1, respectively, where VR is the volume of reaction). The cerebellum data were fitted using a model without specific binding. All the parameters were estimated using nonlinear mathematical models of the ligand-receptor interactions including or not including nonspecific binding. The plasma time-concentration curve was used as an input function after correction for the metabolites. An estimate of standard errors was obtained for each PET study and for each identified parameter using the covariance matrix. The average values of B'max and KdVR were 73 +/- 11 pmol/ml tissue and 1.9 +/- 0.9 pmol/ml, respectively. The nonspecific binding was identifiable in the experiment where the last injection corresponded to a second coinjection. We found that approximately 6% of the striatal binding was nonspecific after a tracer injection of [76Br]BLIS. The nonspecific binding appeared to be reversible in the striatum but irreversible in the cerebellum.


Assuntos
Encéfalo/metabolismo , Lisurida/análogos & derivados , Receptores Dopaminérgicos/metabolismo , Tomografia Computadorizada de Emissão , Animais , Encéfalo/diagnóstico por imagem , Radioisótopos de Bromo , Cerebelo/metabolismo , Simulação por Computador , Corpo Estriado/metabolismo , Lisurida/sangue , Lisurida/metabolismo , Masculino , Modelos Biológicos , Concentração Osmolar , Papio , Receptores de Dopamina D2 , Fatores de Tempo
6.
Clin Pharmacol Ther ; 35(4): 548-56, 1984 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-6705456

RESUMO

The single and multiple oral dose plasma kinetics of lisuride were followed by a recently developed radioimmunoassay method in 11 patients with Parkinson's disease. A very wide range of plasma drug concentrations resulted from a single dose of 300 micrograms, as reflected in large interindividual differences in peak concentration (0.27 to 3.30 ng/ml) and AUC after the initial dose (43.1 to 617 ng X min/ml). Absorption was rapid, with a mean time to peak of 39 min. Only 0.05% of the dose was excreted unchanged in urine in 24 hr. There was a 110% increase in apparent oral clearance after 2 to 4 wk of treatment.


Assuntos
Ergolinas/metabolismo , Lisurida/metabolismo , Doença de Parkinson/metabolismo , Administração Oral , Idoso , Disponibilidade Biológica , Feminino , Humanos , Cinética , Lisurida/uso terapêutico , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/tratamento farmacológico , Radioimunoensaio
7.
Psychopharmacology (Berl) ; 70(3): 223-9, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-6777796

RESUMO

In rats, lisuride, either administered systemically or intracerebroventricularly induced a dose-related hypothermia. This effect was selectively antagonized by blockade of DA receptors in the CNS but not by inhibition of catecholamine synthesis or blockade of serotoninergic receptors. Also a blocker of "peripheral" DA receptors failed to antagonize the hypothermic effect of lisuride in rats. Induction of rat liver microsomal drug-metabolizing enzymes by phenobarbital counteracted lisuride-induced hypothermia. In rabbits lisuride induced a hyperthermic response which was sensitive to both pimozide and metergoline pretreatment. These findings indicate that stimulation of brain DA receptors involved in thermoregulation is responsible for the changes in body temperature indiced by lisuride in rats and rabbits and that these effects are caused by the drug itself and do not require previous biotransformation into an active metabolite.


Assuntos
Temperatura Corporal/efeitos dos fármacos , Ergolinas/farmacologia , Lisurida/farmacologia , Microssomos Hepáticos/metabolismo , Receptores Dopaminérgicos/efeitos dos fármacos , Animais , Benzimidazóis/farmacologia , Biotransformação , Domperidona , Lisurida/metabolismo , Masculino , Fenobarbital/farmacologia , Pimozida/farmacologia , Piperidinas/farmacologia , Coelhos , Fatores de Tempo
8.
Psychopharmacology (Berl) ; 75(2): 119-23, 1981.
Artigo em Inglês | MEDLINE | ID: mdl-6798600

RESUMO

The effects of bromocriptine, lisuride and apomorphine on specific binding of 3H-spiroperidol to homogenates of rat caudate nucleus were studied. (+)-Butaclamol was used to define specific binding. Bromocriptine and lisuride inhibited binding markedly, in vitro and also 30 min after in vivo injection. Bromocriptine continued to inhibit binding 24h after a single injection and also after 4 days of drug administration. Lisuride did not affect net specific binding at these periods. Apomorphine produced a mild reduction in binding after 30 min but none after 4 days. It appears that the ergot alkaloids inhibit binding of 3H-spiroperidol by binding strongly to the dopamine receptor.


Assuntos
Antiparkinsonianos/metabolismo , Ergolinas/metabolismo , Receptores Dopaminérgicos/metabolismo , Animais , Apomorfina/metabolismo , Bromocriptina/metabolismo , Núcleo Caudado , Ergolinas/farmacologia , Lisurida/metabolismo , Ratos , Ratos Endogâmicos , Receptores Dopaminérgicos/efeitos dos fármacos , Espiperona/metabolismo
9.
Psychopharmacology (Berl) ; 136(4): 409-14, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9600588

RESUMO

Evidence from studies with phenylisopropylamine hallucinogens indicates that the 5HT2A receptor is the likely target for the initiation of events leading to hallucinogenic activity associated with LSD and related drugs. Recently, lisuride (a purported non-hallucinogenic congener of LSD) was reported to be a potent antagonist at the 5HT2C receptor and an agonist at the 5HT2A receptor. LSD exhibited agonist activity at both receptors. These data were interpreted as indicating that the 5HT2C receptor might be the initiating site of action for hallucinogens. To test this hypothesis, recombinant cells expressing 5HT2A and 5HT2C receptors were used to determine the actions of LSD and lisuride. LSD and lisuride were potent partial agonists at 5HT2A receptors with EC50 values of 7.2 nM and 17 nM, respectively. Also, LSD and lisuride were partial agonists at 5HT2C receptors with EC50 values of 27 nM and 94 nM, respectively. We conclude that lisuride and LSD have similar actions at 5HT2A and 5HT2C receptors in recombinant cells. As agonist activity at brain 5HT2A receptors has been associated with hallucinogenic activity, these results indicate that lisuride may possess hallucinogenic activity, although the psychopharmacological effects of lisuride appear to be different from the hallucinogenic effects of LSD.


Assuntos
Lisurida/metabolismo , Dietilamida do Ácido Lisérgico/metabolismo , Receptores de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/metabolismo , Células 3T3 , Animais , Fosfatos de Inositol/biossíntese , Lisurida/farmacologia , Dietilamida do Ácido Lisérgico/farmacologia , Camundongos , Receptor 5-HT2A de Serotonina , Receptor 5-HT2C de Serotonina , Receptores de Serotonina/efeitos dos fármacos , Agonistas do Receptor de Serotonina/farmacologia
10.
Psychopharmacology (Berl) ; 164(1): 93-107, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12373423

RESUMO

RATIONALE: There is substantial evidence that lisuride can produce effects linked to 5-HT(1A) receptor occupancy. Nevertheless, this action has generally been ignored in the mechanism of action of lisuride, in favor of an exclusive role for dopamine receptors in considering its antiparkinsonian effects, or an exclusive role of 5-HT(2A/2C) receptor activation in hallucinogenesis. These conclusions are surprising when one considers that the potent interaction of lisuride with 5-HT(1A) receptors has been demonstrated in several different laboratories and that activation of 5-HT(1A) and 5-HT(1B) receptors can modulate dopaminergically mediated responses. OBJECTIVE: The lack of full substitution of lisuride for lysergic acid diethylamide (LSD) in drug discrimination experiments and induction of a pronounced 5-HT syndrome by this compound at relatively low doses convinced us to execute two series of experiments that might explain the primary mechanism responsible for lisuride-mediated biological effects and its paradoxical classification as a dopamine agonist in the literature. RESULTS: In drug discrimination studies, lisuride fully mimicked the 5-HT(1A) agonist LY 293284, only partially substituted for LSD and DOI, and failed to substitute for (+)-amphetamine. Lisuride produced a significant dose-related increase in flat body posture, forepaw treading, and lower-lip retraction which reflect a modulation of behavior by action at central 5-HT(1A) receptors. Only pMPPI [4-iodo-N-[2-[4-(methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridynyl-benzamide hydrochloride], a selective 5-HT(1A) antagonist, was effective in inhibiting all 5-HT syndrome behaviors produced by lisuride, whereas pMPPI was without effect on any behavior induced by LSD. Lisuride dose dependently decreased body temperature in rats with a potency similar to that of the selective 5-HT(1A) agonist LY 293284. The hypothermic effect of lisuride was prevented by pre-injection of pMPPI, but not by ketanserin or haloperidol. CONCLUSION: We have demonstrated that the behavioral effects of low doses of lisuride are clearly mediated by stimulation of 5-HT(1A) receptors.


Assuntos
Temperatura Corporal/efeitos dos fármacos , Discriminação Psicológica/efeitos dos fármacos , Lisurida/farmacologia , Receptores de Serotonina/fisiologia , Animais , Temperatura Corporal/fisiologia , Células CHO , Cricetinae , Discriminação Psicológica/fisiologia , Relação Dose-Resposta a Droga , Humanos , Lisurida/metabolismo , Dietilamida do Ácido Lisérgico/metabolismo , Dietilamida do Ácido Lisérgico/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Receptores de Serotonina/metabolismo , Receptores 5-HT1 de Serotonina , Agonistas do Receptor de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/farmacologia
11.
Brain Res ; 248(1): 185-7, 1982 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-7127137

RESUMO

[3H]Lisuride binding to rat striatal membranes appeared to be stereospecifically displaced by the dopamine antagonist butaclamol. Sodium increased the number of [3H]lisuride binding sites (Bmax) without changing the dissociation constant (Kd). GTP did not affect [3H]lisuride binding characteristics, either with or without sodium. These results suggest that dopamine receptor sites labeled by lisuride are at least in part sodium-dependent, possibly the D2-receptors not involved in adenylate cyclase stimulation.


Assuntos
Corpo Estriado/efeitos dos fármacos , Ergolinas/metabolismo , Guanosina Trifosfato/farmacologia , Lisurida/metabolismo , Receptores Dopaminérgicos/efeitos dos fármacos , Sódio/farmacologia , Animais , Apomorfina/metabolismo , Corpo Estriado/metabolismo , Técnicas de Cultura , Cinética , Masculino , Ratos , Ratos Endogâmicos , Receptores Dopaminérgicos/metabolismo
12.
Eur J Pharmacol ; 127(3): 239-47, 1986 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-2944753

RESUMO

Bromolisuride, an ergoline derivative, was labeled with the positron emitter radionuclide, bromine 76. In vitro and in vivo binding and competition studies in rats demonstrated a high affinity (KD = 0.3 nM) and a high specificity of this new radioligand for D-2 dopamine receptors. PET kinetic studies in baboons showed an accumulation of [76Br]bromolisuride in the striatum which reached a maximum 30 min post-injection and which could be displaced by haloperidol. All these results indicated that this new ligand is certainly suitable for the non-invasive in vivo quantitative imaging of D-2 dopamine receptor sites in human brain.


Assuntos
Encéfalo/metabolismo , Ergolinas/metabolismo , Lisurida/metabolismo , Receptores Dopaminérgicos/metabolismo , Animais , Bromo , Corpo Estriado/metabolismo , Lisurida/análogos & derivados , Masculino , Papio , Radioisótopos , Ratos , Ratos Endogâmicos , Receptores de Dopamina D2 , Tomografia Computadorizada de Emissão
13.
Eur J Pharmacol ; 136(1): 97-101, 1987 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-3297739

RESUMO

The binding properties of [3H]terguride were studied in various regions of the rat brain. The highest density of [3H]terguride binding sites was found in the striatum and tuberculum olfactorium. In the striatum, the binding was saturable, stereoselective and of a high affinity. There was a good correlation between the inhibition of [3H]terguride and [3H]spiperone bindings by various dopaminergic agents. Drugs with affinity to another type of receptors did not displace [3H]terguride binding in the striatum; only SCH 23390 was effective. The experiments indicate a certain affinity of the ligand to D-1 receptors. Nevertheless, [3H]terguride appears to have an affinity to D-2 receptors in the striatum and, thanks to its dopamine agonistic/antagonistic profile, would be useful in the further study of dopamine receptors.


Assuntos
Corpo Estriado/metabolismo , Ergolinas/metabolismo , Lisurida/metabolismo , Receptores Dopaminérgicos/efeitos dos fármacos , Animais , Benzazepinas/farmacologia , Corpo Estriado/efeitos dos fármacos , Técnicas In Vitro , Cinética , Lisurida/análogos & derivados , Masculino , Ratos , Ratos Endogâmicos , Espiperona/metabolismo
14.
Eur J Pharmacol ; 293(3): 183-90, 1995 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-8666035

RESUMO

Expression of human cytochrome (CYP) in heterologous cells is a means of specifically studying the role of these enzymes in drug metabolism. The complete cDNA encoding CYP3A4 (PCN1) was inserted into an expression vector containing the strong myeloproliferative sarcoma virus promoter in combination with the enhancer of the cytomegalovirus and stably expressed in V79 Chinese hamster cells. The presence of genomically integrated CYP3A4 cDNA cell clones was confirmed by polymerase chain reaction analysis. Transcription was detected by reverse transcribed polymerase chain reaction analysis. Functional expression could be demonstrated by conversion of testosterone to the specific 6beta-hydroxylated product. In recombinant V79 cells expressing CYP3A4 about 6% of the substrate was converted to 6beta-hydroxytestosterone. The metabolism of two dopaminergic ergot derivatives was investigated in live recombinant V79 cells. Both lisuride and terguride were monodeethylated.


Assuntos
Sistema Enzimático do Citocromo P-450/biossíntese , Sistema Enzimático do Citocromo P-450/genética , Agonistas de Dopamina/metabolismo , Fibroblastos/enzimologia , Regulação Enzimológica da Expressão Gênica , Oxigenases de Função Mista/biossíntese , Oxigenases de Função Mista/genética , Animais , Linhagem Celular , Células Cultivadas , Clonagem Molecular , Cricetinae , Cricetulus , Citocromo P-450 CYP3A , Vetores Genéticos , Humanos , Lisurida/análogos & derivados , Lisurida/metabolismo , Fígado/enzimologia , Plasmídeos , Reação em Cadeia da Polimerase , Testosterona/metabolismo , Transcrição Gênica , Transfecção
15.
Nucl Med Biol ; 23(3): 373-6, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8782250

RESUMO

By variation of reaction parameters iodination of 3-(9,10-didehydro-6-methyl-8 alpha-ergolinyl)-1,1-diethylurea (lisuride) was performed with the radiohalogen [123I]iodine (t1/2 = 13.3 h). For comparative experiments and stability studies the beta(-)-emitting radioisotope [131I]iodine (t1/2 = 8.04 d) was also used. Reaction occurs at the activated position 2 of the molecule, thus leading to [123I]3-(9,10-didehydro-2-iodo-6-methyl-8 alpha-ergolinyl)-1,1-diethylurea ([123I]2-iodo-lisuride, [123I]ILIS) or the analogous [131I]iodine-labeled compound, respectively. Electrophilic radioactive species were generated by oxidation of no-carrier-added (n.c.a.) iodide with IODOGEN (1,3,4,6-tetrachloro-3 alpha,6 alpha-diphenylglycouril) fixed on the glass wall of the reaction vial prior to iodination. After optimization of reaction parameters [123I]2-iodo-lisuride after HPLC-purification was obtained with radiochemical yields of 70 +/- 5% and a radiochemical purity of > 97%. In n.c.a. syntheses, specific activities of the product were in the range between 4440 and 7400 GBq/mumol (120-200 Ci/mumol) corresponding to 50-85% of the theoretical value.


Assuntos
Radioisótopos do Iodo , Lisurida/análogos & derivados , Receptores de Dopamina D2/metabolismo , Ciclotrons , Estabilidade de Medicamentos , Marcação por Isótopo/métodos , Lisurida/síntese química , Lisurida/metabolismo , Receptores de Dopamina D2/análise , Ureia/análogos & derivados
16.
Nucl Med Biol ; 26(1): 91-8, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10096507

RESUMO

The effects of moderate changes in extracellular dopamine concentrations on the in vivo binding of specific dopaminergic D2 radioligands with different affinities and kinetics were investigated in rats. Either [125I]NCQ298 (Kd = 19 pM), or [25I]iodolisuride (Kd = 0.27 nM) or [3H]raclopride (Kd = 1.5 nM) were administered intravenously (IV) to animals 1 h after the intraperitoneal (IP) injection of either alpha-methyl-p-tyrosine (AMPT) (250 mg/kg) or nomifensine (15 mg/kg), or saline. The kinetics of radioactivity concentration in the striatum, cerebellum, and plasma were measured for up to 4 h after [125I]NCQ298 or [125I]iodolisuride injection and up to 1.5 h after [3H]raclopride injection. For each tracer, the striatum-to-cerebellum radioactivity concentration ratios (S/C) and the binding potential (BP), calculated as the association to dissociation binding rate constant ratios (k3/k4), were assessed and related to the changes in extracellular dopamine concentration induced by drug treatments. Results show that S/C and BP of [3H]raclopride were significantly diminished by pretreatment with nomifensine, a drug that increases extracellular dopamine concentration. Nomifensine pretreatment induced no changes in the in vivo binding indexes of the high affinity [125I]NCQ298 and a slight but not significant decrease of the binding indexes of 125I]iodolisuride. Treatment with AMPT, which induced a 40% reduction in dopamine concentration, did not change [125I]NCQ298 binding indexes but slightly increased those of [3H]raclopride and [125I]iodolisuride. In conclusion, the change of dopamine concentration induces modification of radiotracer kinetics. Thus, the combined use of tracers with high and low affinities could allow us to obtain information both on receptor density and neurotransmitter release in vivo. However, as indicated by the [3H]raclopride study with AMPT, small changes in the concentration of intrasynaptic dopamine cannot be easily detected.


Assuntos
Cerebelo/metabolismo , Dopamina/farmacologia , Receptores de Dopamina D2/metabolismo , Córtex Visual/metabolismo , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Animais , Cerebelo/efeitos dos fármacos , Dopamina/metabolismo , Radioisótopos do Iodo , Lisurida/análogos & derivados , Lisurida/metabolismo , Masculino , Nomifensina/farmacologia , Racloprida , Compostos Radiofarmacêuticos/metabolismo , Ratos , Ratos Wistar , Salicilamidas/metabolismo , Tomografia Computadorizada de Emissão , Trítio , Córtex Visual/efeitos dos fármacos , alfa-Metiltirosina/farmacologia
17.
Nuklearmedizin ; 34(4): 141-5, 1995 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-7675643

RESUMO

The goal was to visualize cerebral dopamine-D2 receptors in 6 patients with Parkinson's disease and in 3 healthy controls using iodine-123-Lisuride-SPECT. In addition, we performed receptor-replacement studies using 123I-Lisuride and cold Lisuride as competitive ligands. The highest uptake of 123I-Lisuride was observed in the striatum, a region with known high dopamine receptor density. In two patients premedication with cold Lisuride displaced 123I-Lisuride from the dopamine receptor. 123I-Lisuride is valuable as a radiotracer in cerebral dopamine-D2 receptor scintigraphy. Whether or not it is possible to determine dynamic changes of dopamine receptor density or function by receptor replacement studies needs further evaluation in larger patient populations.


Assuntos
Encéfalo/diagnóstico por imagem , Radioisótopos do Iodo , Lisurida , Doença de Parkinson/diagnóstico por imagem , Adulto , Idoso , Ligação Competitiva , Encéfalo/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Lisurida/metabolismo , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/metabolismo , Receptores de Dopamina D2/metabolismo , Valores de Referência , Tomografia Computadorizada de Emissão de Fóton Único
18.
Physiol Res ; 53(1): 35-43, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14984312

RESUMO

Pergolide, terguride and N,N'-spacer-linked oligomers of both have been tested for their ability to interact with 5 hydroxytryptamine(HT)2A receptors of rat tail artery. Pergolide was a potent partial agonist (pEC50 7.5, Emax 55 %) and antagonized 5-HT-induced contractions (pKp 7.2). Pergolide dimer 3 with a p-xylene spacer between the indole nitrogens (N-1) displayed somewhat lower agonist potency than pergolide (pEC50 7.0, Emax 55 %, pKp 6.6). The contractile responses to pergolide and dimer 3 were antagonized by the 5-HT2A receptor antagonist ketanserin (pA2 9.4, 9.1). In contrast to pergolide dimer 3, pergolide dimers 5 and 9 with an alkyl and an aralkyl spacer between the piperidine nitrogens (N-6) lacked agonism and displayed low affinity at 5-HT2A receptors (pA2 < 5.5). Terguride behaved as an insurmountable antagonist of 5-HT (pA2 8.4). Oligomers of terguride showed 5 to 50-fold lower affinity. It is concluded that pergolide and terguride show a high affinity for 5-HT2A receptors, but dimerization (oligomerization) of both drugs fails to increase affinity.


Assuntos
Artérias/efeitos dos fármacos , Agonistas de Dopamina/farmacologia , Lisurida/análogos & derivados , Lisurida/farmacologia , Pergolida/farmacologia , Receptor 5-HT2A de Serotonina/metabolismo , Animais , Artérias/metabolismo , Dimerização , Agonistas de Dopamina/química , Agonistas de Dopamina/metabolismo , Relação Dose-Resposta a Droga , Lisurida/química , Lisurida/metabolismo , Masculino , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , Pergolida/química , Pergolida/metabolismo , Ratos , Ratos Wistar , Serotonina/farmacologia , Cauda/irrigação sanguínea , Vasoconstrição/efeitos dos fármacos
19.
Eur J Drug Metab Pharmacokinet ; 12(1): 31-40, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3609071

RESUMO

Bromerguride is a novel dopamine antagonistic ergot derivative in which a complete reversed pharmacodynamic profile has been obtained by bromine substitution at position 2 as compared to dopamine agonistic lisuride. The pharmacokinetics of the new drug has been investigated following i.v. and i.g. administration of the 14C-labelled compound to rat (R) and beagle dog (D) with regard to drug registration requirements and to serve other preclinical disciplines (toxicology, pharmacology). Because of incomplete absorption the oral bioavailability was approx. 40% at dose levels of 0.25 mg/kg (R, D) and 4 mg/kg (D) and 20% after i.g. dosing of 5 mg/kg (R). Most of the 14C-label in plasma consisted of unchanged bromerguride apart from small amounts of the N-monodesethyl metabolite, which was also obtained as a biodegradation product in a rat liver perfusion experiment. Bromerguride plasma levels declined with half-lives of 0.7 h and 9 h (R) and 0.2 h and 2.7 h (D) after i.v. treatment. Peak levels in rat brain and plasma were observed within 1-2 h after oral dosing; brain levels accounting for 1/10 of bromerguride plasma levels. Whole body autoradiographs in rat demonstrated that the 14C-label was rapidly distributed into tissues and organs, readily passed the blood-brain and the placental barrier. Bromerguride was excreted to less than 10% unchanged with urine. Excretion was mainly biliary. Most of the 14C-label was recovered in the excreta within 24 h postdose.


Assuntos
Antagonistas de Dopamina , Ergolinas/metabolismo , Alcaloides de Claviceps/metabolismo , Lisurida/metabolismo , Animais , Autorradiografia , Biotransformação , Encéfalo/metabolismo , Cães , Alcaloides de Claviceps/administração & dosagem , Fezes/análise , Meia-Vida , Injeções Intravenosas , Cinética , Lisurida/administração & dosagem , Lisurida/análogos & derivados , Perfusão , Ratos , Especificidade da Espécie
20.
Eur J Drug Metab Pharmacokinet ; 9(4): 347-57, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6532807

RESUMO

14C-labelled lisuride hydrogen maleate was administered intravenously (25 micrograms) and orally (200 micrograms) to three male and three female elderly volunteers. Following i.v. injection radioimmunologically determined plasma levels of unchanged lisuride showed a three-phasic decline with half-lives of 3 minutes, 16 minutes and 2.9 hours. The total clearance was 16 +/- 9 ml/min/kg. Bioavailability was estimated to be 14% of oral dose. Determination of 14C-radioactivity did not show any specific enrichment of lisuride metabolites in cellular components of blood. The drug was almost totally metabolized and its degradation products were eliminated equally via the kidney and liver. Total recovery was about 90% of dose. The elimination half-life was 10 hours. Small parts of the dose administered were renally excreted with a half-life of 23 hours. Lisuride is metabolized extensively. HPLC radiochromatograms of freely extractable metabolites from urine did not show marked differences between both routes of administration. More than 15 compounds were freely extractable, only one of them represented more than 5% of dose. Phase II reactions were quantitatively unimportant. From rhesus monkey urine 6 metabolites were isolated. Chemical structures were proposed for 5 of them. They were assigned to the pattern of freely extractable human urinary metabolites and covered about 50% of radiolabel corresponding to about 13% of dose. The main freely extractable urinary metabolite was thought to be the 2-keto-3-hydroxy-lisuride derivative. Structures of the other four metabolites and earlier observations on the stability of the N'-ethyl-3H label led to the interpretation of independent changes of lisuride by different enzymatic processes such as oxidative N-deethylation, hydroxylation of the benzene system, monooxygenation at C2 and C9, and oxidation of double bonds at C2/C3 and C9/C10.


Assuntos
Ergolinas/metabolismo , Lisurida/metabolismo , Animais , Biotransformação , Proteínas Sanguíneas/metabolismo , Fezes/análise , Feminino , Humanos , Cinética , Lisurida/sangue , Lisurida/urina , Macaca mulatta , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Ligação Proteica , Espectrofotometria Infravermelho
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