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1.
Am Heart J ; 217: 52-63, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31493728

RESUMO

Anticoagulation in children is problematic for multiple reasons. Currently used anticoagulants have significant disadvantages and may negatively affect quality of life (QOL). This manuscript describes the design, rationale, and methods of a prospective, randomized, open label phase II multi-national clinical trial of a direct oral anticoagulant (DOAC), apixaban, in children and infants with congenital and acquired heart disease. This trial is designed to gather preliminary safety and pharmacokinetics (PK) data, as well as generate data on QOL of individuals taking apixaban compared to the standard of care (SOC) anticoagulants vitamin K antagonists (VKA) or low molecular weight heparin (LMWH). A key issue this trial seeks to address is the practice of using therapeutics tested in adult trials in the pediatric population without robust pediatric safety or efficacy data. Pediatric heart diseases are not common, and specific diagnoses often meet the criteria of a rare disease; thus, statistical efficacy may be difficult to achieve. This trial will provide valuable PK and safety data intended to inform clinical practice for anticoagulation in pediatric heart diseases, a setting in which a fully powered phase III clinical trial is not feasible. A second consideration this trial addresses is that metrics besides efficacy, such as QOL, have not been traditionally used as endpoints in regulated anticoagulation studies yet may add substantial weight to the clinical decision for use of a DOAC in place of VKA or LMWH. This study examines QOL related to both heart disease and anticoagulation among children randomized to either SOC or apixaban. There are considerable strengths and benefits to conducting a clinical trial in pediatric rare disease populations via an industry-academic collaboration. The SAXOPHONE study represents a collaboration between Bristol-Myers Squibb (BMS)/Pfizer Alliance, and the National Heart, Lung, and Blood Institute's (NHLBI) Pediatric Heart Network (PHN) and may be an attractive model for future pediatric drug trials.

2.
Thromb Haemost ; 119(5): 844-853, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30861550

RESUMO

Venous thromboembolic (VTE) complications in children and adolescents with acute lymphoblastic leukaemia (ALL) and T or B cell lymphoblastic lymphoma (T/B cell LL) can result not only in life-threatening acute complications but also contribute to significant long-term sequelae. The PREVAPIX-ALL study is an open-label randomized controlled study comparing outcomes of treatment with prophylactic dose apixaban versus no anticoagulation (standard of care) in children and adolescents with ALL and T/B cell LL receiving standard induction chemotherapy with asparaginase and the presence of a central venous access device. On day 29 of induction, all patients undergo screening imaging with duplex ultrasonography and echocardiography. The primary efficacy endpoint of the study is a composite of symptomatic and asymptomatic VTE that includes deep vein thrombosis, pulmonary embolism, cerebral sinovenous thrombosis or VTE-related death. The primary safety outcome is major bleeding. Secondary outcomes are central line-associated infections, patency and line replacement, superficial thrombosis, arterial events and death. A planned sample size of 500 randomized paediatric patients enrolled over a period of 5 years is based on the estimation of VTE rates of 20 and 10% in the standard of care and apixaban groups, respectively. An optional biomarker study in 150 patients will examine predictors of increased VTE risk and study in vivo anticoagulant effects of apixaban in children by measuring specific biomarkers in the haemostatic system and inflammatory pathway. This study will provide valuable information for the safety and efficacy of apixaban in VTE prevention during induction in paediatric ALL.

4.
Bioorg Med Chem Lett ; 27(3): 590-596, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28011221

RESUMO

The design and synthesis of a series of tripeptide acylsulfonamides as potent inhibitors of the HCV NS3/4A serine protease is described. These analogues house a C4 aryl, C4 hydroxy-proline at the S2 position of the tripeptide scaffold. Information relating to structure-activity relationships as well as the pharmacokinetic and cardiovascular profiles of these analogues is provided.


Assuntos
Antivirais/química , Hepacivirus/enzimologia , Oligopeptídeos/química , Inibidores de Proteases/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Meia-Vida , Coração/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Humanos , Técnicas In Vitro , Oligopeptídeos/farmacocinética , Oligopeptídeos/farmacologia , Prolina/química , Inibidores de Proteases/farmacocinética , Inibidores de Proteases/farmacologia , Coelhos , Ratos , Relação Estrutura-Atividade , Sulfonamidas/química , Proteínas não Estruturais Virais/metabolismo
5.
J Med Chem ; 59(17): 8042-60, 2016 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-27564532

RESUMO

The discovery of a back-up to the hepatitis C virus NS3 protease inhibitor asunaprevir (2) is described. The objective of this work was the identification of a drug with antiviral properties and toxicology parameters similar to 2, but with a preclinical pharmacokinetic (PK) profile that was predictive of once-daily dosing. Critical to this discovery process was the employment of an ex vivo cardiovascular (CV) model which served to identify compounds that, like 2, were free of the CV liabilities that resulted in the discontinuation of BMS-605339 (1) from clinical trials. Structure-activity relationships (SARs) at each of the structural subsites in 2 were explored with substantial improvement in PK through modifications at the P1 site, while potency gains were found with small, but rationally designed structural changes to P4. Additional modifications at P3 were required to optimize the CV profile, and these combined SARs led to the discovery of BMS-890068 (29).


Assuntos
Antivirais/química , Hepacivirus/efeitos dos fármacos , Isoquinolinas/uso terapêutico , Oligopeptídeos/química , Sulfonamidas/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/administração & dosagem , Antivirais/farmacocinética , Antivirais/farmacologia , Cães , Esquema de Medicação , Farmacorresistência Viral , Hepacivirus/genética , Macaca fascicularis , Masculino , Modelos Moleculares , Oligopeptídeos/administração & dosagem , Oligopeptídeos/farmacocinética , Oligopeptídeos/farmacologia , Coelhos , Ratos Sprague-Dawley , Replicon , Estereoisomerismo , Relação Estrutura-Atividade , Sulfonamidas/administração & dosagem , Sulfonamidas/farmacocinética , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico
6.
J Med Chem ; 58(22): 9010-26, 2015 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-26524347

RESUMO

Cholesteryl ester transfer protein (CETP) inhibitors raise HDL-C in animals and humans and may be antiatherosclerotic by enhancing reverse cholesterol transport (RCT). In this article, we describe the lead optimization efforts resulting in the discovery of a series of triphenylethanamine (TPE) ureas and amides as potent and orally available CETP inhibitors. Compound 10g is a potent CETP inhibitor that maximally inhibited cholesteryl ester (CE) transfer activity at an oral dose of 1 mg/kg in human CETP/apoB-100 dual transgenic mice and increased HDL cholesterol content and size comparable to torcetrapib (1) in moderately-fat fed hamsters. In contrast to the off-target liabilities with 1, no blood pressure increase was observed with 10g in rat telemetry studies and no increase of aldosterone synthase (CYP11B2) was detected in H295R cells. On the basis of its preclinical profile, compound 10g was advanced into preclinical safety studies.


Assuntos
Anticolesterolemiantes/síntese química , Anticolesterolemiantes/farmacologia , Benzamidas/síntese química , Benzamidas/farmacologia , Benzilaminas/síntese química , Benzilaminas/farmacologia , Proteínas de Transferência de Ésteres de Colesterol/antagonistas & inibidores , Animais , Anticolesterolemiantes/farmacocinética , Aterosclerose/tratamento farmacológico , Benzamidas/farmacocinética , Benzilaminas/farmacocinética , Pressão Sanguínea/efeitos dos fármacos , Linhagem Celular , Colesterol/metabolismo , HDL-Colesterol/sangue , Cricetinae , Citocromo P-450 CYP11B2/antagonistas & inibidores , Cães , Descoberta de Drogas , Humanos , Macaca fascicularis , Masculino , Mesocricetus , Camundongos , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Quinolinas/farmacologia , Ratos , Ratos Sprague-Dawley
7.
Diabetes Care ; 38(11): 2009-17, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26246458

RESUMO

OBJECTIVE: To compare the efficacy and safety of treatment with dapagliflozin versus that with placebo add-on to saxagliptin plus metformin in patients whose type 2 diabetes is inadequately controlled with saxagliptin plus metformin treatment. RESEARCH DESIGN AND METHODS: Patients receiving treatment with stable metformin (stratum A) (screening HbA1c level 8.0-11.5% [64-102 mmol/mol]) or stable metformin and a dipeptidyl peptidase-4 (DPP-4) inhibitor (stratum B) (HbA1c 7.5-10.5% [58-91 mmol/mol]) for ≥8 weeks received open-label saxagliptin 5 mg/day and metformin for 16 weeks (stratum A) or 8 weeks (stratum B) (saxagliptin replaced any DPP-4 inhibitor). Patients with inadequate glycemic control (HbA1c 7-10.5% [53-91 mmol/mol]) were randomized to receive placebo or dapagliflozin 10 mg/day plus saxagliptin and metformin. The primary end point was the change in HbA1c from baseline to week 24. Secondary end points included fasting plasma glucose (FPG) level, 2-h postprandial glucose (PPG) level, body weight, and proportion of patients achieving an HbA1c level of <7% (53 mmol/mol). RESULTS: Treatment with dapagliflozin add-on to saxagliptin plus metformin resulted in a greater mean HbA1c reduction than placebo (-0.82 vs. -0.10% [-9 vs. -1.1 mmol/mol], P < 0.0001). Significantly greater reductions in FPG level, 2-h PPG level, and body weight were observed, and more patients achieved an HbA1c level of <7% (53 mmol/mol) with treatment with dapagliflozin versus placebo. Adverse events were similar across treatment groups, with a low overall risk of hypoglycemia (∼1%). Genital infections developed in more patients with dapagliflozin treatment (5%) than with placebo (0.6%). CONCLUSIONS: Triple therapy with dapagliflozin add-on to saxagliptin plus metformin improves glycemic control and is well tolerated in patients whose type 2 diabetes is inadequately controlled with saxagliptin plus metformin therapy.


Assuntos
Adamantano/análogos & derivados , Compostos Benzidrílicos/administração & dosagem , Diabetes Mellitus Tipo 2/tratamento farmacológico , Dipeptídeos/uso terapêutico , Glucosídeos/administração & dosagem , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Adamantano/administração & dosagem , Adamantano/efeitos adversos , Adamantano/uso terapêutico , Adulto , Idoso , Compostos Benzidrílicos/efeitos adversos , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/epidemiologia , Dipeptídeos/administração & dosagem , Dipeptídeos/efeitos adversos , Método Duplo-Cego , Quimioterapia Combinada/métodos , Feminino , Glucosídeos/efeitos adversos , Humanos , Hipoglicemia/induzido quimicamente , Hipoglicemia/epidemiologia , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Masculino , Metformina/administração & dosagem , Metformina/efeitos adversos , Pessoa de Meia-Idade , Resultado do Tratamento , Infecções Urinárias/induzido quimicamente , Infecções Urinárias/epidemiologia
8.
Bioorg Med Chem Lett ; 25(21): 4983-4986, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25801931

RESUMO

Phenethyl aminoheterocycles like compound 1 were known to be potent I(Kur) blockers although they lacked potency in vivo. Modification of the heterocycle led to the design and synthesis of pseudosaccharin amines. Compounds such as 14, 17d and 21c were found to be potent K(V)1.5 blockers and selective over other cardiac ion channels. These compounds had potent pharmacodynamic activity, however, they also showed off-target activities such as hemodynamic effects.


Assuntos
Aminas/farmacologia , Canal de Potássio Kv1.5/antagonistas & inibidores , Bloqueadores dos Canais de Potássio/farmacologia , Aminas/síntese química , Aminas/química , Animais , Pressão Sanguínea/efeitos dos fármacos , Cicloexanos/química , Cicloexanos/farmacologia , Relação Dose-Resposta a Droga , Humanos , Canal de Potássio Kv1.5/metabolismo , Camundongos , Estrutura Molecular , Bloqueadores dos Canais de Potássio/síntese química , Bloqueadores dos Canais de Potássio/química , Coelhos , Ratos , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Relação Estrutura-Atividade
9.
Bioorg Med Chem Lett ; 24(14): 3018-22, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24881565

RESUMO

Phenethylaminoheterocycles have been prepared and assayed for inhibition of the Kv1.5 potassium ion channel as a potential approach to the treatment of atrial fibrillation. A diverse set of heterocycles were identified as potent Kv1.5 inhibitors and were advanced to pharmacodynamic evaluation based on selectivity and pharmacokinetic profile. Heterocycle optimization and template modification lead to the identification of compound 24 which demonstrated increased atrial effective refractory period in the rabbit pharmacodynamic model with mild effects on blood pressure and heart rate.


Assuntos
Carbamatos/farmacologia , Desenho de Drogas , Indazóis/farmacologia , Canal de Potássio Kv1.5/antagonistas & inibidores , Bloqueadores dos Canais de Potássio/farmacologia , Animais , Carbamatos/síntese química , Carbamatos/química , Relação Dose-Resposta a Droga , Átrios do Coração/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Humanos , Indazóis/síntese química , Indazóis/química , Modelos Moleculares , Estrutura Molecular , Bloqueadores dos Canais de Potássio/síntese química , Bloqueadores dos Canais de Potássio/química , Coelhos , Ratos , Relação Estrutura-Atividade
10.
J Med Chem ; 57(5): 1708-29, 2014 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-24555570

RESUMO

The discovery of BMS-605339 (35), a tripeptidic inhibitor of the NS3/4A enzyme, is described. This compound incorporates a cyclopropylacylsulfonamide moiety that was designed to improve the potency of carboxylic acid prototypes through the introduction of favorable nonbonding interactions within the S1' site of the protease. The identification of 35 was enabled through the optimization and balance of critical properties including potency and pharmacokinetics (PK). This was achieved through modulation of the P2* subsite of the inhibitor which identified the isoquinoline ring system as a key template for improving PK properties with further optimization achieved through functionalization. A methoxy moiety at the C6 position of this isoquinoline ring system proved to be optimal with respect to potency and PK, thus providing the clinical compound 35 which demonstrated antiviral activity in HCV-infected patients.


Assuntos
Antivirais/uso terapêutico , Descoberta de Drogas , Hepatite C/tratamento farmacológico , Isoquinolinas/uso terapêutico , Inibidores de Proteases/uso terapêutico , Sulfonamidas/uso terapêutico , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Cristalografia por Raios X , Cães , Avaliação Pré-Clínica de Medicamentos , Humanos , Isoquinolinas/química , Modelos Moleculares , Inibidores de Proteases/química , Sulfonamidas/química
11.
Bioorg Med Chem Lett ; 24(5): 1294-8, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24513044

RESUMO

Spiropiperidine indoline-substituted diaryl ureas had been identified as antagonists of the P2Y1 receptor. Enhancements in potency were realized through the introduction of a 7-hydroxyl substitution on the spiropiperidinylindoline chemotype. SAR studies were conducted to improve PK and potency, resulting in the identification of compound 3e, a potent, orally bioavailable P2Y1 antagonist with a suitable PK profile in preclinical species. Compound 3e demonstrated a robust antithrombotic effect in vivo and improved bleeding risk profile compared to the P2Y12 antagonist clopidogrel in rat efficacy/bleeding models.


Assuntos
Compostos de Fenilureia/química , Inibidores da Agregação de Plaquetas/química , Antagonistas do Receptor Purinérgico P2Y/química , Receptores Purinérgicos P2Y1/química , Tiazóis/química , Ureia/análogos & derivados , Administração Oral , Animais , Cães , Meia-Vida , Macaca fascicularis , Compostos de Fenilureia/farmacocinética , Compostos de Fenilureia/farmacologia , Compostos de Fenilureia/uso terapêutico , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/farmacocinética , Inibidores da Agregação de Plaquetas/farmacologia , Inibidores da Agregação de Plaquetas/uso terapêutico , Antagonistas do Receptor Purinérgico P2Y/farmacocinética , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Antagonistas do Receptor Purinérgico P2Y/uso terapêutico , Ratos , Receptores Purinérgicos P2Y1/metabolismo , Relação Estrutura-Atividade , Tiazóis/farmacocinética , Tiazóis/farmacologia , Tiazóis/uso terapêutico , Trombose/tratamento farmacológico , Ureia/farmacocinética , Ureia/farmacologia , Ureia/uso terapêutico
12.
J Med Chem ; 57(5): 1730-52, 2014 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-24564672

RESUMO

The discovery of asunaprevir (BMS-650032, 24) is described. This tripeptidic acylsulfonamide inhibitor of the NS3/4A enzyme is currently in phase III clinical trials for the treatment of hepatitis C virus infection. The discovery of 24 was enabled by employing an isolated rabbit heart model to screen for the cardiovascular (CV) liabilities (changes to HR and SNRT) that were responsible for the discontinuation of an earlier lead from this chemical series, BMS-605339 (1), from clinical trials. The structure-activity relationships (SARs) developed with respect to CV effects established that small structural changes to the P2* subsite of the molecule had a significant impact on the CV profile of a given compound. The antiviral activity, preclincial PK profile, and toxicology studies in rat and dog supported clinical development of BMS-650032 (24).


Assuntos
Antivirais/uso terapêutico , Hepatite C/tratamento farmacológico , Isoquinolinas/uso terapêutico , Inibidores de Proteases/uso terapêutico , Sulfonamidas/uso terapêutico , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/sangue , Antivirais/química , Cães , Humanos , Isoquinolinas/sangue , Isoquinolinas/química , Modelos Moleculares , Inibidores de Proteases/sangue , Inibidores de Proteases/química , Coelhos , Ratos , Sulfonamidas/sangue , Sulfonamidas/química
14.
Cardiovasc Res ; 91(3): 420-8, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21622683

RESUMO

AIMS: Previous studies suggested that T-type Ca(2+)-current (I(CaT))-blockers improve cardiac remodelling, but all available I(CaT)-blockers have non-specific actions on other currents and/or functions. To clarify the role of I(CaT) in cardiac remodelling, we studied mice with either of the principal cardiac I(CaT)-subunits (Cav3.1 or Cav3.2) knocked out. METHODS AND RESULTS: Adult male Cav3.1- or Cav3.2-knockout (Cav3.1(-/-), Cav3.2(-/-)) mice and respective wild-type (WT) littermate controls were subjected to left anterior descending coronary artery ligation to create myocardial infarction (MI). Echocardiography and programmed electrical stimulation were performed at baseline and 4 weeks post-MI. At baseline, Cav3.1(-/-) mice had slowed heart rates and longer PR intervals vs. WT, but no other electrophysiological and no haemodynamic differences. Cav3.2(-/-) showed no differences vs. WT. Contractile indices (left ventricular fractional shortening and ejection fraction) decreased more post-MI in Cav3.1(-/-) mice than in Cav3.1(+/+) (e.g. by 34 and 29% for WT; 50 and 45% for Cav3.1(-/-), respectively; P < 0.05 for each). Cav3.1(-/-) mice had increased ventricular tachycardia (VT) inducibility post-MI (9 of 11, 82%) vs. WT (3 of 10, 30%; P < 0.05). Cav3.2(-/-) mice were not different in cardiac function or VT inducibility vs. WT. Quantitative polymerase chain reaction showed that Cav3.1 is the major I(CaT)-subunit and that no compensatory Cav3.2 up-regulation occurs in Cav3.1(-/-) mice. Cav3.1(-/-) and Cav3.2(-/-) mice had no mRNA expression for the knocked-out gene, at baseline or post-MI. CONCLUSION: Our findings suggest that, contrary to suggestions from previous studies with (imperfectly selective) pharmacological agents having T-type Ca(2+)-channel-blocking actions, elimination of Cav3.1 expression leads to impaired cardiac function and enhanced arrhythmia vulnerability post-MI, whereas Cav3.2 elimination has no effect.


Assuntos
Canais de Cálcio Tipo T/metabolismo , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Remodelação Ventricular , Animais , Canais de Cálcio Tipo T/deficiência , Canais de Cálcio Tipo T/genética , Estimulação Cardíaca Artificial , Modelos Animais de Doenças , Eletrocardiografia , Frequência Cardíaca , Hemodinâmica , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Contração Miocárdica , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/genética , Miocárdio/patologia , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Volume Sistólico , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/genética , Taquicardia Ventricular/metabolismo , Fatores de Tempo , Ultrassonografia , Função Ventricular Esquerda
16.
Mol Pharmacol ; 76(6): 1211-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19767451

RESUMO

Successful development of 5-HT(2C) agonists requires selectivity versus the highly homologous 5-HT(2A) receptor, because agonism at this receptor can result in significant adverse events. (R)-9-Ethyl-1,3,4,10b-tetrahydro-7-trifluoromethylpyrazino[2,1-a]isoindol-6(2H)-one (compound 1) is a potent 5-HT(2C) agonist exhibiting selectivity over the human 5-HT(2A) receptor. Evaluation of the compound at the rat 5-HT(2A) receptor, however, revealed potent binding and agonist functional activity. The physiological consequence of this higher potency was the observation of a significant increase in blood pressure in conscious telemeterized rats that could be prevented by ketanserin. Docking of compound 1 in a homology model of the 5-HT(2A) receptor indicated a possible binding mode in which the ethyl group at the 9-position of the molecule was oriented toward position 5.46 of the 5-HT(2A) receptor. Within the human 5-HT(2A) receptor, position 5.46 is Ser242; however, in the rat 5-HT(2A) receptor, it is Ala242, suggesting that the potent functional activity in this species resulted from the absence of the steric bulk provided by the -OH moiety of the Ser in the human isoform. We confirmed this hypothesis using site-directed mutagenesis through the mutation of both the human receptor Ser242 to Ala and the rat receptor Ala242 to Ser, followed by radioligand binding and second messenger studies. In addition, we attempted to define the space allowed by the alanine by evaluating compounds with larger substitutions at the 9-position. The data indicate that position 5.46 contributed to the species difference in 5-HT(2A) receptor potency observed for a pyrazinoisoindolone compound, resulting in the observation of a significant cardiovascular safety signal.


Assuntos
Isoindóis/farmacologia , Pirazinas/farmacologia , Agonistas do Receptor 5-HT2 de Serotonina , Animais , Ligação Competitiva/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Cálcio/metabolismo , Linhagem Celular , Cães , Variação Genética , Humanos , Isoindóis/metabolismo , Ketanserina/farmacologia , Macaca fascicularis , Masculino , Atividade Motora/efeitos dos fármacos , Mutagênese Sítio-Dirigida , Ligação Proteica/efeitos dos fármacos , Pirazinas/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina/efeitos dos fármacos , Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2C de Serotonina/genética , Receptor 5-HT2C de Serotonina/fisiologia , Homologia de Sequência de Aminoácidos , Antagonistas da Serotonina/farmacologia , Especificidade da Espécie , Homologia Estrutural de Proteína
17.
Bioorg Med Chem Lett ; 19(18): 5469-73, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19665893

RESUMO

Dihydropyrazolopyrimidines with a C6 heterocycle substituent were found to have high potency for block of K(V)1.5. Investigation of the substitution in the benzimidazole ring and the substituent in the 5-position of the dihydropyrazolopyrimidine ring produced 31a with an IC50 for K(V)1.5 block of 0.030muM without significant block of other cardiac ion channels. This compound also showed good bioavailability in rats and robust pharmacodynamic effects in a rabbit model.


Assuntos
Canal de Potássio Kv1.5/antagonistas & inibidores , Bloqueadores dos Canais de Potássio/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Animais , Fibrilação Atrial/tratamento farmacológico , Linhagem Celular , Humanos , Canal de Potássio Kv1.5/metabolismo , Camundongos , Bloqueadores dos Canais de Potássio/química , Bloqueadores dos Canais de Potássio/farmacocinética , Pirazóis/química , Pirazóis/farmacocinética , Pirimidinas/química , Pirimidinas/farmacocinética , Coelhos , Ratos , Relação Estrutura-Atividade
19.
J Med Chem ; 47(7): 1704-8, 2004 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-15027861

RESUMO

A novel series of dihydro- and tetrahydrotriazolopyridazine-1,3-dione-based amino acid derivatives were identified as very potent motilin receptor agonists. Incorporating one additional phenylethyl glycinamide subunit to 1 (EC(50) = 660 nM) was found to improve in vitro potency approximately 3000-fold, resulting in compound 10 (EC(50) = 0.22 nM). The more potent enantiomer 11A has an EC(50) of 0.047 nM in the motilin receptor functional assay and a K(i) of 0.7 nM in the binding assay. In addition, compound 11A was shown to have a significantly reduced tendency to cause receptor desensitization as compared with the motilin receptor agonist ABT-229.


Assuntos
Motilina/agonistas , Piridazinas/síntese química , Receptores dos Hormônios Gastrointestinais/agonistas , Receptores de Neuropeptídeos/agonistas , Triazóis/síntese química , Sinalização do Cálcio/efeitos dos fármacos , Células HeLa , Humanos , Piridazinas/química , Piridazinas/farmacologia , Receptores dos Hormônios Gastrointestinais/metabolismo , Receptores de Neuropeptídeos/metabolismo , Estereoisomerismo , Relação Estrutura-Atividade , Triazóis/química , Triazóis/farmacologia
20.
Cell Physiol Biochem ; 14(1-2): 31-40, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14976404

RESUMO

Parasympathetic tone and congestive heart failure (CHF) are two of promoting factors in initiation and perpetuation of atrial fibrillation (AF). Recent studies indicate co-existence of multiple muscarinic acetylcholine receptor subtypes (mAChRs) that mediate several distinct K+ currents in the heart; inward rectifier K+ current IKACh by the M2, and two delayed rectifier K+ currents IKM3 and IK4AP by the M3 and M4 receptors, respectively. We studied the alterations of atrial mAChRs and their coupled K+ channels in the setting of AF in dogs with ventricular tachypacing-induced CHF. Whole-patch-clamp recordings showed that the current densities of IKACh (induced by 1 mM acetylcholine) and IK4AP (induced by 1 mM 4-aminopyridine) were ñ45% and ñ55% lower, respectively, while that of IKM3 (induced by 10 mM choline) was ñ75% higher, at a plateau voltage of 0 mV in atrial myocytes from CHF than those from healthy hearts. In healthy hearts, IKACh comprised >60%, and IKM3 and IK4AP <30%, of the total outward K+ currents mediated by mAChRs at depolarized potentials (between -20 mV and +50 mV). In AF atria of CHF dogs, however, the contribution of IKM3 increased to approximately 50%, exceeding those of IKACh or IK4AP. Western blot analyses with atrial membrane protein samples indicated that receptor densities of the M2 and M4 subtypes decreased by approximately 33% and approximately 22%, respectively, whereas that of the M3 subtype increased by approximately 2.3 folds, in parallel to the alterations of the corresponding K+ currents. We conclude that differential alterations of mAChR subtypes underlie differential alterations of their coupled K+ channels in AF atria and these differential alterations may contribute to atrial remodeling in AF induced in the setting of CHF.


Assuntos
Fibrilação Atrial/etiologia , Fibrilação Atrial/fisiopatologia , Átrios do Coração/fisiopatologia , Insuficiência Cardíaca/complicações , Canais de Potássio/fisiologia , Receptores Muscarínicos/fisiologia , Animais , Fibrilação Atrial/patologia , Modelos Animais de Doenças , Cães , Feminino , Átrios do Coração/citologia , Átrios do Coração/patologia , Insuficiência Cardíaca/patologia , Masculino , Técnicas de Patch-Clamp , Receptores Muscarínicos/classificação
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