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2.
Biomed Pharmacother ; 141: 111865, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34246193

RESUMO

The antihyperglycemic potential of syringaldehyde has been previously investigated; however, the underlying mechanism remains unclear. In this study, we performed a postprandial glucose test (in vivo) including oral glucose tolerance test (OGTT) and oral starch tolerance test (OSTT) in fructose-induced diabetic mice on a high-fat diet for mimicking type 2 diabetes to explore the hypoglycemic efficacy of syringaldehyde and the underlined molecular involvement of syringaldehyde in a glucose-lowering effect. The results revealed that syringaldehyde dose-dependently suppressed blood glucose in both the OSTT and OGTT when referenced to acarbose and metformin, respectively. Surprisingly, syringaldehyde triggered jejunum motility (ex vivo) via activation of the muscarinic-type acetylcholine receptor. By performing virtual screening with molecular docking, the data showed that syringaldehyde nicely interacted with glucagon-like peptide 1 receptor (GLP-1R), peroxisome proliferator-activated receptor (PPAR), dipeptidyl peptidase-IV (DPP-4), acetylcholine M2 receptor, and acetylcholinesterase. These results showed that syringaldehyde can potentiate intestinal contractility to abolish the α-amylase reaction when concurrently reducing retention time and glucose absorption to achieve a glucose-lowering effect in diabetic mice, suggesting its potential therapeutic benefits with improvement for use as a prophylactic and treatment.


Assuntos
Benzaldeídos/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Motilidade Gastrointestinal/efeitos dos fármacos , Amido/metabolismo , alfa-Amilases/antagonistas & inibidores , Animais , Glicemia , Diabetes Mellitus Experimental/tratamento farmacológico , Dieta Hiperlipídica , Teste de Tolerância a Glucose , Jejuno/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Simulação de Acoplamento Molecular , Agonistas Muscarínicos/farmacologia , Receptores Muscarínicos/efeitos dos fármacos
3.
Bull Exp Biol Med ; 171(2): 198-201, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34173102

RESUMO

Changes in pulmonary microcirculation were studied in isolated perfused rabbit lungs during modelling pulmonary thromboembolism under conditions of acetylcholine infusion against the background of treatment with M1 acetylcholine receptor blocker pirenzepine or blockade of muscarinic acetylcholine receptors with atropine. In the first case, the increase in pulmonary artery pressure was less pronounced than in case of atropine treatment. In response to pulmonary embolism after acetylcholine infusion against the background of pirenzepine pretreatment, the capillary hydrostatic pressure and postcapillary resistance did not change, while after atropine treatment, these parameters increased. In case of pulmonary embolism after acetylcholine infusion combined with selective blockade of M1 muscarinic acetylcholine receptors, the capillary filtration coefficient increased to a greater extent, than in the control and after blockade of muscarinic acetylcholine receptors.


Assuntos
Antagonistas Muscarínicos/farmacologia , Circulação Pulmonar/efeitos dos fármacos , Embolia Pulmonar , Acetilcolina/farmacologia , Animais , Atropina/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Modelos Animais de Doenças , Pulmão/irrigação sanguínea , Pulmão/efeitos dos fármacos , Microcirculação/efeitos dos fármacos , Nitroglicerina/farmacologia , Circulação Pulmonar/fisiologia , Embolia Pulmonar/patologia , Embolia Pulmonar/fisiopatologia , Coelhos , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/metabolismo , Resistência Vascular/efeitos dos fármacos , Resistência Vascular/fisiologia
4.
Pharmacol Res ; 169: 105641, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33951507

RESUMO

Disruption of cholinergic signalling via muscarinic receptors is associated with various pathologies, like Alzheimer's disease or schizophrenia. Selective muscarinic agonists possess therapeutic potential in the treatment of diabetes, pain or Sjögren's syndrome. The orthosteric binding site of all subtypes of the muscarinic receptor is structurally identical, making the development of affinity-based selective agonists virtually impossible. Some agonists, however, are functionally selective; they activate only a subset of receptors or signalling pathways. Others may stabilise specific conformations of the receptor leading to non-uniform modulation of individual signalling pathways (biased agonists). Functionally selective and biased agonists represent a promising approach for selective activation of individual subtypes of muscarinic receptors. In this work we review chemical structures, receptor binding and agonist-specific conformations of currently known functionally selective and biased muscarinic agonists in the context of their intricate intracellular signalling. Further, we take a perspective on the possible use of biased agonists for tissue and organ-specific activation of muscarinic receptors.


Assuntos
Agonistas Muscarínicos/farmacologia , Humanos , Receptores Muscarínicos/efeitos dos fármacos
5.
Psychopharmacology (Berl) ; 238(8): 2225-2234, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33891128

RESUMO

Episodic memory retrieval is fundamental for daily activities of humans and animals. Muscarinic cholinergic signaling is important for memory functioning and shows gender-dependent response in episodic memory retrieval. Dopamine D2 receptors influence memory formation and retrieval by influencing cholinergic signaling in the brain. This study aimed to determine the gender-dependent effects of D2 and muscarinic activity on memory retrieval. Male and female mice were trained for Morris water maze test and contextual fear conditioning. Memory retrieval was assessed following sub-chronic treatment (for 5 days) with D2 antagonist (risperidone 2.5 mg/kg) alone or in combination with scopolamine (1 mg/kg) or donepezil (1 mg/kg). Open field test was performed prior to the retrieval test to evaluate effects of risperidone treatment on locomotor activity and exploratory behavior. Risperidone co-treatment with donepezil impaired spatial memory retrieval in males only. Muscarinic and D2 simultaneous antagonism tend to impair fear retrieval in males but significantly enhanced retrieval of fear memories in female mice. These results suggest that D2 signaling influence muscarinic receptor activity during memory retrieval in gender-dependent manner.


Assuntos
Medo/fisiologia , Receptores de Dopamina D2/fisiologia , Receptores Muscarínicos/fisiologia , Caracteres Sexuais , Memória Espacial/fisiologia , Animais , Inibidores da Colinesterase/farmacologia , Antagonistas dos Receptores de Dopamina D2/farmacologia , Medo/efeitos dos fármacos , Medo/psicologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Antagonistas Muscarínicos/farmacologia , Receptores Muscarínicos/efeitos dos fármacos , Memória Espacial/efeitos dos fármacos
6.
Am J Physiol Regul Integr Comp Physiol ; 320(6): R871-R884, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33851543

RESUMO

Donepezil is a centrally acting acetylcholinesterase (AChE) inhibitor with therapeutic potential in inflammatory diseases; however, the underlying autonomic and cholinergic mechanisms remain unclear. Here, we assessed effects of donepezil on mean arterial pressure (MAP), heart rate (HR), HR variability, and body temperature in conscious adult male C57BL/6 mice to investigate the autonomic pathways involved. Central versus peripheral cholinergic effects of donepezil were assessed using pharmacological approaches including comparison with the peripherally acting AChE inhibitor, neostigmine. Drug treatments included donepezil (2.5 or 5 mg/kg sc), neostigmine methyl sulfate (80 or 240 µg/kg ip), atropine sulfate (5 mg/kg ip), atropine methyl bromide (5 mg/kg ip), or saline. Donepezil, at 2.5 and 5 mg/kg, decreased HR by 36 ± 4% and 44 ± 3% compared with saline (n = 10, P < 0.001). Donepezil, at 2.5 and 5 mg/kg, decreased temperature by 13 ± 2% and 22 ± 2% compared with saline (n = 6, P < 0.001). Modest (P < 0.001) increases in MAP were observed with donepezil after peak bradycardia occurred. Atropine sulfate and atropine methyl bromide blocked bradycardic responses to donepezil, but only atropine sulfate attenuated hypothermia. The pressor response to donepezil was similar in mice coadministered atropine sulfate; however, coadministration of atropine methyl bromide potentiated the increase in MAP. Neostigmine did not alter HR or temperature, but did result in early increases in MAP. Despite the marked bradycardia, donepezil did not increase normalized high-frequency HR variability. We conclude that donepezil causes marked bradycardia and hypothermia in conscious mice via the activation of muscarinic receptors while concurrently increasing MAP via autonomic and cholinergic pathways that remain to be elucidated.


Assuntos
Sistema Cardiovascular/efeitos dos fármacos , Colinérgicos/farmacologia , Donepezila/farmacologia , Temperatura , Animais , Atropina/farmacologia , Sistema Nervoso Autônomo/fisiopatologia , Pressão Sanguínea/fisiologia , Sistema Cardiovascular/fisiopatologia , Inibidores da Colinesterase/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores Muscarínicos/efeitos dos fármacos
7.
Toxins (Basel) ; 13(4)2021 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-33916832

RESUMO

Arecoline is one of the nicotinic acid-based alkaloids, which is found in the betel nut. In addition to its function as a muscarinic agonist, arecoline exhibits several adverse effects, such as inducing growth retardation and causing developmental defects in animal embryos, including zebrafish, chicken, and mice. In this study, we aimed to study the potential adverse effects of waterborne arecoline exposure on zebrafish larvae locomotor activity and investigate the possible mechanism of the arecoline effects in zebrafish behavior. The zebrafish behavior analysis, together with molecular docking and the antagonist co-exposure experiment using muscarinic acetylcholine receptor antagonists were conducted. Zebrafish larvae aged 96 h post-fertilization (hpf) were exposed to different concentrations (0.001, 0.01, 0.1, and 1 ppm) of arecoline for 30 min and 24 h, respectively, to find out the effect of arecoline in different time exposures. Locomotor activities were measured and quantified at 120 hpf. The results showed that arecoline caused zebrafish larvae locomotor hyperactivities, even at a very low concentration. For the mechanistic study, we conducted a structure-based molecular docking simulation and antagonist co-exposure experiment to explore the potential interactions between arecoline and eight subtypes, namely, M1a, M2a, M2b, M3a, M3b, M4a, M5a, and M5b, of zebrafish endogenous muscarinic acetylcholine receptors (mAChRs). Arecoline was predicted to show a strong binding affinity to most of the subtypes. We also discovered that the locomotion hyperactivity phenotypes triggered by arecoline could be rescued by co-incubating it with M1 to M4 mAChR antagonists. Taken together, by a pharmacological approach, we demonstrated that arecoline functions as a highly potent hyperactivity-stimulating compound in zebrafish that is mediated by multiple muscarinic acetylcholine receptors.


Assuntos
Arecolina/toxicidade , Comportamento Animal/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Agonistas Muscarínicos/toxicidade , Receptores Muscarínicos/efeitos dos fármacos , Animais , Arecolina/metabolismo , Relação Dose-Resposta a Droga , Simulação de Acoplamento Molecular , Agonistas Muscarínicos/metabolismo , Antagonistas Muscarínicos/farmacologia , Fotoperíodo , Ligação Proteica , Receptores Muscarínicos/metabolismo , Transdução de Sinais , Fatores de Tempo , Peixe-Zebra/embriologia
8.
Neurobiol Learn Mem ; 181: 107445, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33895349

RESUMO

In rodent models of smoking during pregnancy, early postnatal nicotine exposure results in impaired hippocampus-dependent memory, but the underlying mechanism remains elusive. Given that hippocampal cholinergic systems modulate memory and rapid development of hippocampal cholinergic systems occurs during nicotine exposure, here we investigated its impacts on cholinergic function. Both nicotinic and muscarinic activation produce transient or long-lasting depression of excitatory synaptic transmission in the hippocampal CA1 region. We found that postnatal nicotine exposure impairs both the induction and nicotinic modulation of NMDAR-dependent long-term depression (LTD). Activation of muscarinic receptors decreases excitatory synaptic transmission and CA1 network activity in both wild-type and α2 knockout mice. These muscarinic effects are still observed in nicotine-exposed mice. M1 muscarinic receptor activity is required for mGluR-dependent LTD. Early postnatal nicotine exposure has no effect on mGluR-dependent LTD induction, suggesting that it has no effect on the function of m1 muscarinic receptors involved in this form of LTD. Our results demonstrate that early postnatal nicotine exposure has more pronounced effects on nicotinic function than muscarinic function in the hippocampal CA1 region. Thus, impaired hippocampus-dependent memory may arise from the developmental disruption of nicotinic cholinergic systems in the hippocampal CA1 region.


Assuntos
Região CA1 Hipocampal/efeitos dos fármacos , Depressão Sináptica de Longo Prazo/efeitos dos fármacos , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Receptor Muscarínico M1/efeitos dos fármacos , Receptores Nicotínicos/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Região CA1 Hipocampal/crescimento & desenvolvimento , Região CA1 Hipocampal/metabolismo , Fumar Cigarros , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Feminino , Lactação , Depressão Sináptica de Longo Prazo/fisiologia , Masculino , Exposição Materna , Memória/efeitos dos fármacos , Memória/fisiologia , Camundongos , Camundongos Knockout , Receptor Muscarínico M1/metabolismo , Receptores de Glutamato Metabotrópico/efeitos dos fármacos , Receptores de Glutamato Metabotrópico/metabolismo , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/metabolismo , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores Nicotínicos/metabolismo
9.
Behav Brain Res ; 405: 113201, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33647377

RESUMO

Schizophrenia is a severe neuropsychiatric disorder characterized by a diverse range of symptoms that can have profound impacts on the lives of patients. Currently available antipsychotics target dopamine receptors, and while they are useful for ameliorating the positive symptoms of the disorder, this approach often does not significantly improve negative and cognitive symptoms. Excitingly, preclinical and clinical research suggests that targeting specific muscarinic acetylcholine receptor subtypes could provide more comprehensive symptomatic relief with the potential to ameliorate numerous symptom domains. Mechanistic studies reveal that M1, M4, and M5 receptor subtypes can modulate the specific brain circuits and physiology that are disrupted in schizophrenia and are thought to underlie positive, negative, and cognitive symptoms. Novel therapeutic strategies for targeting these receptors are now advancing in clinical and preclinical development and expand upon the promise of these new treatment strategies to potentially provide more comprehensive relief than currently available antipsychotics.


Assuntos
Antipsicóticos/farmacologia , Clozapina/farmacologia , Disfunção Cognitiva/tratamento farmacológico , Agonistas Muscarínicos/farmacologia , Piridinas/farmacologia , Receptores Muscarínicos/efeitos dos fármacos , Esquizofrenia/tratamento farmacológico , Tiadiazóis/farmacologia , Animais , Disfunção Cognitiva/etiologia , Humanos , Esquizofrenia/complicações , Esquizofrenia/fisiopatologia
10.
Neurotoxicol Teratol ; 84: 106957, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33539933

RESUMO

BACKGROUND: Phosalone (Pln) is an organophosphorus pesticide acetylcholinesterase (AChE) inhibitor. Blockade of AChE amplifies ACh signaling that is related to depressive symptoms. The effects of Pln exposure were evaluated on depressive behavior in mice and the involvement of muscarinic ACh receptor (MAChR) was assessed. MATERIAL AND METHODS: After measuring total activity in the locomotor test the immobility time during the forced swimming test (FST) in male mice was evaluated as an index of depression. Pln single dose was administered by gavage feeding and examined after 3 h (day1) and on day 7 for evaluating delayed toxicity. In separate groups Pln was administered for 5 consecutive days and examined on day 6 also after one-week delay on day12. RESULTS: While there were only marginal differences in the locomotor tests. Immobility time during the FST significantly increased on day1 by Pln 6, 12, 40 mg/kg (185 ±â€¯17 s, 186 ±â€¯9 s, 172.0 ±â€¯7 s respectively) compared with control animals (149 ±â€¯8 s, p < 0.01), immobility time was higher than control on day 6 after multiple exposures to Pln (0.6, 6, 12, 20 mg/kg 190 ±â€¯20s, 210 ±â€¯4 s, 196 ±â€¯10s, 204 ±â€¯9 respectively, vs control 153 ±â€¯7 p < 0.001). The immobility time remained high following a week of relapse. The co-administration of Pln with scopolamine (Scp) a MAChR antagonist reduced immobility time (141 ±â€¯10s vs Pln 186 ±â€¯9 s, p < 0.01). CONCLUSION: Single exposure to Pln induced depressive-like effects that were reversed by Scp, indicating that MAChR stimulation may be involved. While cumulative exposures caused more pronounced changes in depressive behavior that remained after a week from the last exposure.


Assuntos
Comportamento Animal/efeitos dos fármacos , Inibidores da Colinesterase/toxicidade , Depressão/induzido quimicamente , Depressão/psicologia , Compostos Organotiofosforados/toxicidade , Praguicidas/toxicidade , Receptores Muscarínicos/efeitos dos fármacos , Animais , Masculino , Camundongos , Atividade Motora , Antagonistas Muscarínicos/farmacologia , Escopolamina/farmacologia , Natação/psicologia
11.
Schizophr Bull ; 47(3): 672-681, 2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33289848

RESUMO

An association between antipsychotic drugs and pneumonia has been demonstrated in several studies; however, the risk for pneumonia caused by specific antipsychotics has not been extensively studied. The underlying mechanism is still unknown, and several receptor mechanisms have been proposed. Therefore, using a combined pharmacovigilance-pharmacodynamic approach, we aimed to investigate safety signals of US Food and Drug Administration (FDA)-approved antipsychotics for reporting pneumonia and the potential receptor mechanisms involved. A disproportionality analysis was performed to detect a signal for reporting "infective-pneumonia" and "pneumonia-aspiration" and antipsychotics using reports submitted between 2004 and 2019 to the FDA adverse events spontaneous reporting system (FAERS) database. Disproportionality was estimated using the crude and the adjusted reporting odds ratio (aROR) and its 95% confidence interval (CI) in a multivariable logistic regression. Linear regressions investigated the relationship between aROR and receptor occupancy, which was estimated using in vitro receptor-binding profiles. Safety signals for reporting infective-pneumonia were identified for clozapine (LL = 95% 3.4, n = 546 [aROR: 4.8]) as well as olanzapine (LL = 95% 1.5, n = 250 [aROR: 2.1]) compared with haloperidol, while aRORs were associated with higher occupancies of muscarinic receptors (beta = .125, P-value = .016), yet other anti-muscarinic drugs were not included as potential confounders. No safety signals for reporting pneumonia-aspiration were detected for individual antipsychotics. Multiple antipsychotic use was associated with both reporting infective-pneumonia (LL 95%: 1.1, n = 369 [aROR:1.2]) and pneumonia-aspiration (LL 95%: 1.7, n = 194 [aROR: 2.0]). Considering the limitations of disproportionality analysis, further pharmacovigilance data and clinical causality assessment are needed to validate this safety signal.


Assuntos
Antipsicóticos/efeitos adversos , Antipsicóticos/farmacocinética , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Farmacovigilância , Pneumonia/induzido quimicamente , Receptores Muscarínicos/efeitos dos fármacos , Adolescente , Adulto , Sistemas de Notificação de Reações Adversas a Medicamentos , Idoso , Idoso de 80 Anos ou mais , Clozapina/efeitos adversos , Clozapina/farmacocinética , Bases de Dados Factuais , Feminino , Haloperidol/efeitos adversos , Haloperidol/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade , Olanzapina/efeitos adversos , Olanzapina/farmacocinética , Pneumonia Aspirativa/induzido quimicamente , Estados Unidos , United States Food and Drug Administration , Adulto Jovem
12.
Neurobiol Learn Mem ; 177: 107360, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33307182

RESUMO

Over the years, experimental and clinical evidence has given support to the idea that acetylcholine (Ach) plays an essential role in mnemonic phenomena. On the other hand, the Hippocampus is already known to have a key role in learning and memory. What is yet unclear is how the Ach receptors may contribute to this brain region role during memory retrieval. The Ach receptors are divided into two broad subtypes: the ionotropic nicotinic acetylcholine receptors and the metabotropic muscarinic acetylcholine receptors. Back in 2010, we demonstrated for the first time the critical role of hippocampal α7 nicotinic acetylcholine receptors in memory reconsolidation process of an inhibitory avoidance response in mice. In the present work, we further investigate the possible implication of hippocampal muscarinic Ach receptors (mAchRs) in this process using a pharmacological approach. By specifically administrating agonists and antagonists of the different mAchRs subtypes in the hippocampus, we found that M1 and M2 but not M3 subtype may be involved in memory reconsolidation processes in mice.


Assuntos
Hipocampo/fisiologia , Consolidação da Memória/fisiologia , Receptores Muscarínicos/fisiologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Hipocampo/efeitos dos fármacos , Masculino , Consolidação da Memória/efeitos dos fármacos , Camundongos , Agonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacologia , Oxotremorina/análogos & derivados , Oxotremorina/farmacologia , Pirenzepina/farmacologia , Receptores Muscarínicos/efeitos dos fármacos , Escopolamina/farmacologia , Succinato de Solifenacina/farmacologia
13.
Neurosci Lett ; 740: 135466, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33152457

RESUMO

The sense of taste provides information regarding the nutrient content, safety or potential toxicity of an edible. This is accomplished via a combination of innate and learned taste preferences. In conditioned taste aversion (CTA), rats learn to avoid ingesting a taste that has previously been paired with gastric malaise. Recent evidence points to a role of cholinergic muscarinic signaling in the amygdala for the learning and storage of emotional memories. The present study tested the participation of muscarinic receptors in the amygdala during the formation of CTA by infusing the non-specific antagonist scopolamine into the basolateral or central subnuclei before or after conditioning, as well as before retrieval. Our data show that regardless of the site of infusion, pre-conditioning administration of scopolamine impaired CTA acquisition whereas post-conditioning infusion did not affect its storage. Also, infusions into the basolateral but not in the central amygdala before retrieval test partially reduced the expression of CTA. Our results indicate that muscarinic receptors activity is required for acquisition but not consolidation of CTA. In addition, our data add to recent evidence pointing to a role of cholinergic signaling in peri-hippocampal structures in the process of memory retrieval.


Assuntos
Tonsila do Cerebelo/fisiologia , Aprendizagem da Esquiva/fisiologia , Receptores Muscarínicos/fisiologia , Transdução de Sinais/fisiologia , Paladar/fisiologia , Tonsila do Cerebelo/efeitos dos fármacos , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Emoções , Masculino , Consolidação da Memória/efeitos dos fármacos , Rememoração Mental/efeitos dos fármacos , Microinjeções , Antagonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/farmacologia , Sistema Nervoso Parassimpático/efeitos dos fármacos , Sistema Nervoso Parassimpático/fisiologia , Ratos , Ratos Wistar , Receptores Muscarínicos/efeitos dos fármacos , Escopolamina/administração & dosagem , Escopolamina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Paladar/efeitos dos fármacos
14.
Am J Physiol Heart Circ Physiol ; 319(6): H1153-H1161, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33035444

RESUMO

Neural control of the heart is regulated by sympathetic and parasympathetic divisions of the autonomic nervous system, both opposing each other to maintain cardiac homeostasis via regulating heart rate, conduction velocity, force of contraction, and coronary blood flow. Sympathetic hyperactivity and diminished parasympathetic activity are the characteristic features of many cardiovascular disease states including hypertension, myocardial ischemia, and arrhythmias that result in heart failure. Restoring parasympathetic activity to the heart has recently been identified as the promising approach to treat such conditions. However, approaches that used vagal nerve stimulation have been shown to be unsuccessful in heart failure. This review focuses on novel chemogenetic approaches used to identify the cardioprotective nature of activating neural points along the vagal pathway (both central and peripheral) while being selectively therapeutic in heart failure and obstructive sleep apnea.


Assuntos
Colina O-Acetiltransferase/metabolismo , Ativadores de Enzimas/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Coração/inervação , Agonistas Muscarínicos/uso terapêutico , Receptores Muscarínicos/efeitos dos fármacos , Apneia Obstrutiva do Sono/tratamento farmacológico , Nervo Vago/efeitos dos fármacos , Animais , Colina O-Acetiltransferase/genética , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Humanos , Ligantes , Ocitocina/metabolismo , Receptores Muscarínicos/genética , Receptores Muscarínicos/metabolismo , Apneia Obstrutiva do Sono/genética , Apneia Obstrutiva do Sono/metabolismo , Apneia Obstrutiva do Sono/fisiopatologia , Nervo Vago/metabolismo , Nervo Vago/fisiopatologia
15.
J Psychopharmacol ; 34(12): 1371-1381, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33103560

RESUMO

BACKGROUND: Thalamic subregions mediate various cognitive functions, including attention, inhibitory response control and decision making. Such neuronal activity is modulated by cholinergic thalamic afferents and deterioration of such modulatory signaling has been theorised to contribute to cognitive decline in neurodegenerative disorders. However, the thalamic subnuclei and cholinergic receptors involved in cognitive functioning remain largely unknown. AIMS: We investigated whether muscarinic or nicotinic receptors in the mediodorsal thalamus and anterior thalamus contribute to rats' performance in the five-choice serial reaction time task, which measures sustained visual attention and impulsive action. METHODS: Male Long-Evans rats were trained in the five-choice serial reaction time task then surgically implanted with guide cannulae targeting either the mediodorsal thalamus or anterior thalamus. Reversible inactivation of either the mediodorsal thalamus or anterior thalamus were achieved with infusions of the γ-aminobutyric acid-ergic agonists muscimol and baclofen prior to behavioural assessment. To investigate cholinergic mechanisms, we also assessed the behavioural effects of locally administered nicotinic (mecamylamine) and muscarinic (scopolamine) receptor antagonists. RESULTS: Reversible inactivation of the mediodorsal thalamus severely impaired discriminative accuracy and response speed and increased omissions. Inactivation of the anterior thalamus produced less profound effects, with impaired accuracy at the highest dose. In contrast, blocking cholinergic transmission in these regions did not significantly affect five-choice serial reaction time task performance. CONCLUSIONS/INTERPRETATIONS: These findings show the mediodorsal thalamus plays a key role in visuospatial attentional performance that is independent of local cholinergic neurotransmission.


Assuntos
Núcleos Anteriores do Tálamo/metabolismo , Atenção/fisiologia , Agonistas GABAérgicos/farmacologia , Comportamento Impulsivo/fisiologia , Núcleo Mediodorsal do Tálamo/metabolismo , Antagonistas Muscarínicos/farmacologia , Antagonistas Nicotínicos/farmacologia , Desempenho Psicomotor/fisiologia , Receptores Muscarínicos/metabolismo , Receptores Nicotínicos/metabolismo , Percepção Espacial/fisiologia , Percepção Visual/fisiologia , Animais , Núcleos Anteriores do Tálamo/efeitos dos fármacos , Atenção/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Agonistas GABAérgicos/administração & dosagem , Comportamento Impulsivo/efeitos dos fármacos , Masculino , Núcleo Mediodorsal do Tálamo/efeitos dos fármacos , Antagonistas Muscarínicos/administração & dosagem , Antagonistas Nicotínicos/administração & dosagem , Desempenho Psicomotor/efeitos dos fármacos , Ratos , Ratos Long-Evans , Receptores Muscarínicos/efeitos dos fármacos , Receptores Nicotínicos/efeitos dos fármacos , Percepção Espacial/efeitos dos fármacos , Percepção Visual/efeitos dos fármacos
16.
Eur J Pharmacol ; 883: 173377, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32687920

RESUMO

Lithium, commonly used to treat bipolar disorder, potentiates the ability of the muscarinic agonist pilocarpine to induce seizures in rodents. As this potentiation by lithium is reversed by the administration of myo-inositol, the potentiation may be mediated by inhibition of inositol monophosphatase (IMPase), a known target of lithium. Recently, we demonstrated that ebselen is a 'lithium mimetic' in regard to behaviours in both mice and man. Ebselen inhibits IMPase in vitro and lowers myo-inositol in vivo in the brains of mice and men, making ebselen the only known inhibitor of IMPase, other than lithium, that penetrates the blood-brain barrier. Our objective was to determine the effects of ebselen on sensitization to pilocarpine-induced seizures and neural activity. We administered ebselen at different doses and time intervals to mice, followed by injection of a sub-seizure dose of pilocarpine. We assessed seizure and neural activity by a subjective seizure rating scale, by monitoring tremors, and by induction of the immediate early gene c-fos. In contrast to lithium, ebselen did not potentiate the ability of pilocarpine to induce seizures. Unexpectedly, ebselen inhibited pilocarpine-induced tremor as well as pilocarpine-induced increases in c-fos mRNA levels. Both lithium and ebselen inhibit a common target, IMPase, but only lithium potentiates pilocarpine-induced seizures, consistent with their polypharmacology at diverse molecular targets. We conclude that ebselen does not potentiate pilocarpine-induced seizures and instead, reduces pilocarpine-mediated neural activation. This lack of potentiation of muscarinic sensitization may be one reason for the lack of side-effects observed with ebselen treatment clinically.


Assuntos
Anticonvulsivantes/farmacologia , Azóis/farmacologia , Encéfalo/efeitos dos fármacos , Cloreto de Lítio/toxicidade , Neurônios/efeitos dos fármacos , Compostos Organosselênicos/farmacologia , Pilocarpina , Convulsões/prevenção & controle , Animais , Anticonvulsivantes/toxicidade , Azóis/toxicidade , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Células CHO , Sinalização do Cálcio/efeitos dos fármacos , Cricetulus , Modelos Animais de Doenças , Fosfatos de Inositol/metabolismo , Isoindóis , Masculino , Camundongos , Neurônios/metabolismo , Compostos Organosselênicos/toxicidade , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Monoéster Fosfórico Hidrolases/metabolismo , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/genética , Receptores Muscarínicos/metabolismo , Convulsões/induzido quimicamente , Convulsões/metabolismo , Convulsões/fisiopatologia
17.
Eur J Pharmacol ; 883: 173183, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32534072

RESUMO

Although agonists and antagonists of muscarinic receptors have been known for long time, there is renewed interest in compounds (such as allosteric or bitopic ligands, or biased agonists) able to differently and selectively modulate these receptors. As a continuation of our previous research, we designed a new series of dimers of the well-known cholinergic agonist carbachol. The new compounds were tested on the five cloned human muscarinic receptors (hM1-5) expressed in CHO cells by means of equilibrium binding experiments, showing a dependence of the binding affinity on the length and position of the linker connecting the two monomers. Kinetic binding studies revealed that some of the tested compounds were able to slow the rate of NMS dissociation, suggesting allosteric behavior, also supported by docking simulations. Assessment of ERK1/2 phosphorylation on hM1, hM2 and hM3 activation showed that the new compounds are endowed with muscarinic antagonist properties. At hM2 receptors, some compounds were able to stimulate GTPγS binding but not cAMP accumulation, suggesting a biased behavior. Classification, Molecular and cellular pharmacology.


Assuntos
Carbacol/farmacologia , Agonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacologia , Receptores Muscarínicos/efeitos dos fármacos , Animais , Células CHO , Carbacol/química , Carbacol/metabolismo , Cricetulus , AMP Cíclico/metabolismo , Dimerização , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Humanos , Cinética , Simulação de Acoplamento Molecular , Estrutura Molecular , Agonistas Muscarínicos/química , Agonistas Muscarínicos/metabolismo , Antagonistas Muscarínicos/química , Antagonistas Muscarínicos/metabolismo , Fosforilação , Ligação Proteica , Receptores Muscarínicos/genética , Receptores Muscarínicos/metabolismo , Transdução de Sinais , Relação Estrutura-Atividade
18.
Life Sci ; 256: 118014, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32593712

RESUMO

The age and strength of fear memory are two potential parameters that can be influenced by the impairing effects of pharmacological agents on reconsolidation of fear memory. In reconsolidation, stored information is rendered labile again after being reactivated. Pharmacological manipulations at this stage result in an inability to retrieve the fear memories, suggesting that they are erased or persistently inhibited. This fear memory impairment phenomenon can be valuable to treat post-traumatic stress disorders (PTSD). Previously ß-adrenergic antagonist propranolol has been repeatedly reported to impair fear memory in the treatment of PTSD. Atropine has also shown to disrupt memory formation. The present study was therefore designed to compare the effects of atropine and propranolol on reconsolidation of older fear memory in rat model of PTSD using Pavlovian fear conditioning apparatus. For this purpose 18 rats were taken and divided into control, atropine and propranolol groups and subjected to Pavlovian fear conditioning trials in order to develop animal model of PTSD. To evaluate the reconsolidation impairment of fear memory by atropine and propranolol, short term and long term memory was tested after reactivation of fear memory in rats. The present findings demonstrate that atropine significantly decreases fear expression. These results suggest that atropine significantly reduces the strength of fear memories and may be effective in the treatment of psychiatric disorders especially in PTSD.


Assuntos
Atropina/farmacologia , Medo/efeitos dos fármacos , Propranolol/farmacologia , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Antagonistas Adrenérgicos beta/farmacologia , Animais , Condicionamento Clássico/efeitos dos fármacos , Modelos Animais de Doenças , Masculino , Memória/efeitos dos fármacos , Antagonistas Muscarínicos/farmacologia , Ratos , Ratos Wistar , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/metabolismo , Transtornos de Estresse Pós-Traumáticos/fisiopatologia
19.
Cereb Cortex ; 30(6): 3528-3542, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32026946

RESUMO

Acetylcholine (ACh) is known to regulate cortical activity during different behavioral states, for example, wakefulness and attention. Here we show a differential expression of muscarinic ACh receptors (mAChRs) and nicotinic ACh receptors (nAChRs) in different layer 6A (L6A) pyramidal cell (PC) types of somatosensory cortex. At low concentrations, ACh induced a persistent hyperpolarization in corticocortical (CC) but a depolarization in corticothalamic (CT) L6A PCs via M 4 and M1 mAChRs, respectively. At ~ 1 mM, ACh depolarized exclusively CT PCs via α4ß2 subunit-containing nAChRs without affecting CC PCs. Miniature EPSC frequency in CC PCs was decreased by ACh but increased in CT PCs. In synaptic connections with a presynaptic CC PC, glutamate release was suppressed via M4 mAChR activation but enhanced by nAChRs via α4ß2 nAChRs when the presynaptic neuron was a CT PC. Thus, in L6A, the interaction of mAChRs and nAChRs results in an altered excitability and synaptic release, effectively strengthening CT output while weakening CC synaptic signaling.


Assuntos
Acetilcolina/metabolismo , Neocórtex/metabolismo , Células Piramidais/metabolismo , Receptores Muscarínicos/metabolismo , Receptores Nicotínicos/metabolismo , Transmissão Sináptica/fisiologia , Acetilcolina/farmacologia , Animais , Agonistas Colinérgicos/farmacologia , Potenciais Pós-Sinápticos Excitadores , Ácido Glutâmico/metabolismo , Neocórtex/efeitos dos fármacos , Vias Neurais , Técnicas de Patch-Clamp , Células Piramidais/efeitos dos fármacos , Ratos , Receptor Muscarínico M1/efeitos dos fármacos , Receptor Muscarínico M1/metabolismo , Receptor Muscarínico M4/efeitos dos fármacos , Receptor Muscarínico M4/metabolismo , Receptores Muscarínicos/efeitos dos fármacos , Receptores Nicotínicos/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Tálamo
20.
Expert Opin Drug Metab Toxicol ; 16(2): 103-110, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31918590

RESUMO

Introduction: Overactive bladder (OAB) has a heterogeneous presentation that varies between individuals and by gender. Treatment with antimuscarinic medications is standard first line pharmacotherapy for most patients with OAB. However, gender specific differences in the pharmacokinetics and pharmacodynamics of antimuscarinic therapy are often overlooked and not discussed.Areas covered: This review will explore differences by gender between the presentation and treatment of OAB. We will discuss the differences between sexes in terms of lower urinary tract anatomy, muscarinic receptors, and hormone variation. The effect of antimuscarinics on males and females as well as adherence and persistence patterns will be reviewed in order to fully review all available literature on the gender specific pharmacokinetic and pharmacodynamic considerations for antimuscarinic use in the treatment of OAB.Expert opinion: Despite extensive research into various antimuscarinic formulations and therapeutic regimens for the treatment of OAB, identification of gender specific pharmacokinetic and pharmacodynamics considerations remains scant. As our knowledge and understanding of OAB, muscarinic receptors, and antimuscarinic medications evolve, we will hopefully be better able to understand and implement gender-specific and genomic-sprecific treatment regimens and considerations for improved clinical outcomes.


Assuntos
Antagonistas Muscarínicos/administração & dosagem , Bexiga Urinária Hiperativa/tratamento farmacológico , Animais , Feminino , Humanos , Masculino , Adesão à Medicação , Antagonistas Muscarínicos/farmacocinética , Antagonistas Muscarínicos/farmacologia , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/metabolismo , Fatores Sexuais , Bexiga Urinária Hiperativa/fisiopatologia
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