RESUMO
Butaphosphan is an organic phosphorus compound used in several species for the prevention of rapid catabolic states, however, the mechanism of action remains unclear. This study aimed at determining the effects of butaphosphan on energy metabolism of mice receiving a normal or hypercaloric diet (HCD) and submitted or not to food restriction. Two experiments were conducted: (1) during nine weeks, animals were fed with HCD (n = 28) ad libitum, and at the 10th week, were submitted to food restriction and received butaphosphan (n = 14) or saline injections (n = 14) (twice a day, for seven days) and; (2) during nine weeks, animals were fed with a control diet (n = 14) or HCD (n = 14) ad libitum, and at the 10th week, all animals were submitted to food restriction and received butaphosphan or saline injections (twice a day, for seven days). In food restriction, butaphosphan preserved epididymal white adipose tissue (WAT) mass, increased glucose, NEFA, and the HOMA index. In mice fed HCD and submitted to food restriction, the butaphosphan preserved epididymal WAT mass. Control diet influences on PI3K, GCK, and Irs1 mRNA expression. In conclusion, butaphosphan increased blood glucose and reduced fat mobilization in overweight mice submitted to caloric restriction, and these effects are influenced by diet.
Assuntos
Glicemia/efeitos dos fármacos , Butilaminas/farmacologia , Dieta , Metabolismo Energético/efeitos dos fármacos , Insulina/metabolismo , Ácidos Fosfínicos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Animais , Glicemia/genética , Glicemia/metabolismo , Restrição Calórica , Ingestão de Energia , Ácidos Graxos não Esterificados/sangue , Expressão Gênica , Resistência à Insulina , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sobrepeso/metabolismoRESUMO
Around 60-80% of oocytes maturated in vivo reached competence, while the proportion of maturation in vitro is rarely higher than 40%. In this sense, butafosfan has been used in vivo to improve metabolic condition of postpartum cows, and can represent an alternative to increase reproductive efficiency in cows. The aim of this study was to evaluate the addition of increasing doses of butafosfan during oocyte maturation in vitro on the initial embryo development in cattle. In total, 1400 cumulus-oocyte complexes (COCs) were distributed in four groups and maturated according to supplementation with increasing concentrations of butafosfan (0 mg/ml, 0.05 mg/ml, 0.1 mg/ml and 0.2 mg/ml). Then, 20 oocytes per group were collected to evaluate nuclear maturation and gene expression on cumulus cells and oocytes and the remaining oocytes were inseminated and cultured until day 7, when blastocysts were collected for gene expression analysis. A dose-dependent effect of butafosfan was observed, with decrease of cleavage rate and embryo development with higher doses. No difference between groups was observed in maturation rate and expression of genes related to oocyte quality. Our results suggest that butafosfan is prejudicial for oocytes, compromising cleavage and embryo development.
Assuntos
Blastocisto/fisiologia , Butilaminas/farmacologia , Técnicas de Maturação in Vitro de Oócitos/veterinária , Oócitos/efeitos dos fármacos , Ácidos Fosfínicos/farmacologia , Animais , Butilaminas/administração & dosagem , Bovinos , Relação Dose-Resposta a Droga , Feminino , Fertilização in vitro , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Técnicas de Maturação in Vitro de Oócitos/métodos , Oócitos/fisiologia , Ácidos Fosfínicos/administração & dosagemRESUMO
In different pathological situations, cardiac cells undergo hyperosmotic stress and cell shrinkage. This change in cellular volume has been associated with contractile dysfunction and cell death. However, the intracellular mechanisms involved in hyperosmotic stress-induced cell death have not been investigated in depth in adult cardiac myocytes. Given that osmotic stress has been shown to promote endoplasmic reticulum stress (ERS), a recognized trigger for apoptosis, we examined whether hyperosmotic stress triggers ERS in adult cardiac myocytes and if so whether this mechanism mediates hyperosmotic stress-induced cell death. Adult rat cardiomyocytes cultured overnight in a hypertonic solution (HS) containing mannitol as the osmolite, showed increased expression of ERS markers, GRP78, CHOP and cleaved-Caspase-12, compared with myocytes in isotonic solution (IS), suggesting that hyperosmotic stress induces ERS. In addition, HS significantly reduced cell viability and increased TUNEL staining and the expression of active Caspase-3, indicative of apoptosis. These effects were prevented with the addition of the ERS inhibitor, 4-PBA, indicating that hyperosmotic stress-induced apoptosis is mediated by ERS. Hyperosmotic stress-induced apoptosis was also prevented when cells were cultured in the presence of a Ca2+-chelating agent (EGTA) or the CaMKII inhibitor (KN93), suggesting that hyperosmotic stress-induced ERS is mediated by a Ca2+ and CaMKII-dependent mechanism. Similar results were observed when hyperosmotic stress was induced using glucose as the osmolite. We conclude that hyperosmotic stress promotes ERS by a CaMKII-dependent mechanism leading to apoptosis of adult cardiomyocytes. More importantly, we demonstrate that hyperosmotic stress-triggered ERS contributes to hyperglycemia-induced cell death.
Assuntos
Apoptose , Estresse do Retículo Endoplasmático , Hiperglicemia , Miócitos Cardíacos/patologia , Animais , Apoptose/efeitos dos fármacos , Butilaminas/farmacologia , Sinalização do Cálcio , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Hiperglicemia/induzido quimicamente , Masculino , Manitol , Pressão Osmótica , Cultura Primária de Células , Ratos , Ratos WistarRESUMO
Synthetic cathinones continue to proliferate in clandestine drug markets worldwide. N-ethylnorpentylone (also known as N-ethylpentylone or ephylone) is a popular emergent cathinone, yet little information is available about its toxicology and pharmacology. Here we characterize the analytical quantification, clinical presentation, and pharmacological mechanism of action for N-ethylnorpentylone. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was used to quantify N-ethylnorpentylone in blood obtained from human cases. Clinical features exhibited by the intoxicated individuals are described. The activity of N-ethylnorpentylone at plasma membrane transporters for dopamine (DAT), norepinephrine (NET) and 5-HT (SERT) was assessed using in vitro assays measuring uptake inhibition and evoked release of [3 H] neurotransmitters in rat brain synaptosomes. Our LC-MS/MS method assayed N-ethylnorpentylone concentrations with limits of detection and quantification of 1 and 5 ng/mL, respectively. Quantitation was linear from 5 to 500 ng/mL, and the method displayed specificity and reproducibility. Circulating concentrations of N-ethylnorpentylone ranged from 7 to 170 ng/mL in clinical cases, and the associated symptoms included palpitations, tachycardia, agitation, hallucinations, coma and death. N-Ethylnorpentylone was a potent inhibitor at DAT (IC50 = 37 nM), NET (IC50 = 105 nM) and SERT (IC50 = 383 nM) but displayed no transporter releasing activity. We present a validated method for quantifying N-ethylnorpentylone in human case work. The drug is a psychomotor stimulant capable of inducing serious cardiovascular and neurological side-effects which can be fatal. In vitro findings indicate that N-ethylnorpentylone exerts its effects by potent blockade of DAT and NET, thereby elevating extracellular levels of dopamine and norepinephrine in the brain and periphery.
Assuntos
Benzodioxóis/sangue , Benzodioxóis/farmacologia , Butilaminas/sangue , Butilaminas/farmacologia , Adolescente , Adulto , Animais , Benzodioxóis/toxicidade , Butilaminas/toxicidade , Estimulantes do Sistema Nervoso Central/sangue , Estimulantes do Sistema Nervoso Central/farmacologia , Estimulantes do Sistema Nervoso Central/toxicidade , Cromatografia Líquida , Inibidores da Captação de Dopamina/sangue , Inibidores da Captação de Dopamina/farmacologia , Feminino , Humanos , Limite de Detecção , Masculino , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/antagonistas & inibidores , Ratos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Inibidores Seletivos de Recaptação de Serotonina/sangue , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Sinaptossomos/metabolismo , Espectrometria de Massas em Tandem , Adulto JovemRESUMO
In this study, 1-(4-di-hydroxy-3,5-dioxa-4-borabicyclo[4.4.0]deca-7,9,11-trien-9-yl)-2-(tert-butylamino)ethanol, (BR-AEA), was designed, synthesized, characterized and tested in docking studies and in vitro. Previous to its synthesis, a set of compounds, including well-known ligands and boron containing compounds, were studied under docking simulations. BR-AEA showed greater affinity than these well-known agonists and was found to be slightly closer than salbutamol to the residues in the TM5 and TM3 of the beta(2) adrenoceptor (beta(2)AR), making a greater number of interactions with them, including some that are apparently key to greater affinity and beta(2)AR activation. This study suggests that affinity is closely related to the interactions of the boron atom, as well as the capacity of boronic acid moieties to make a network of hydrogen bonds with the beta(2)AR. In vitro, the relaxing effects of BR-AEA on isolated guinea pig tracheal rings were compared with salbutamol. The EC(50) values for BR-AEA were at least five-fold lower than for salbutamol, showing the greater potency of the former. Additionally, propranolol and ICI 118,551 showed competitive antagonism in relation to the relaxing effect of the test compound (pA(2) 6.204+/-0.367 and 9.089+/-0.470, respectively).
Assuntos
Agonistas de Receptores Adrenérgicos beta 2 , Compostos Bicíclicos com Pontes/síntese química , Compostos Bicíclicos com Pontes/farmacologia , Butilaminas/síntese química , Butilaminas/farmacologia , Biologia Computacional , Desenho de Fármacos , Etanol/síntese química , Etanol/farmacologia , Albuterol/análogos & derivados , Animais , Sítios de Ligação , Compostos Bicíclicos com Pontes/química , Compostos Bicíclicos com Pontes/metabolismo , Butilaminas/química , Butilaminas/metabolismo , Etanol/química , Etanol/metabolismo , Cobaias , Humanos , Ligantes , Masculino , Modelos Moleculares , Conformação Molecular , Receptores Adrenérgicos beta 2/química , Receptores Adrenérgicos beta 2/metabolismo , Traqueia/efeitos dos fármacos , Traqueia/metabolismoRESUMO
The heme pathway enzyme delta-aminolevulinate dehydratase is a good marker for oxidative stress and metal intoxication. This sulfhydryl enzyme is inhibited in such oxidative pathologies as lead, mercury and aluminum intoxication, exposure to selenium organic species and diabetes. Oxidative stress is a complicating factor in diabetes, inducing non-enzymatic glucose-mediated reactions that change protein structures and impair enzyme functions. We have studied the effects of high glucose, fructose and ribose concentrations on delta-ALA-D activity in vitro. These reducing sugars inhibited delta-ALA-D with efficacies in the order fructose=ribose>glucose. The possible mechanism of glucose inhibition was investigated using lysine, DTT, and t-butylamine. Oxidation of the enzyme's critical sulfhydryl groups was not involved because DTT had no effect. We concluded that high concentrations of reducing sugars or their autoxidation products inhibit delta-ALA-D by a mechanism not related to thiol oxidation. Also, we are not able to demonstrate that the formation of a Schiff base with the critical lysine residue of the enzyme is involved in the inhibition of delta-ALA-D by hexoses.
Assuntos
Eritrócitos/enzimologia , Frutose/farmacologia , Glucose/farmacologia , Sintase do Porfobilinogênio/antagonistas & inibidores , Ribose/farmacologia , Compostos de Sulfidrila/química , Butilaminas/farmacologia , Ditiotreitol/farmacologia , Humanos , Lisina/farmacologia , Masculino , Oxirredução , Sintase do Porfobilinogênio/sangue , Edulcorantes/farmacologiaRESUMO
New nitro- and aminoquinoline derivatives containing a pyridyl nucleus were synthesized from 6, 8-disubstituted 4-methyl-2-pyridylquinolines, which were prepared from N-pyridylmethylidenanilines. The anti-chagasic and trichomonacidal in vitro activity, as well as the cytotoxic properties towards macrophages of some of these compounds were evaluated. Although some of the compounds showed only moderate activity it was possible to establish some structure-activity relationships.
Assuntos
Aminoquinolinas/síntese química , Compostos de Anilina/síntese química , Antitricômonas/síntese química , Butilaminas/síntese química , Compostos Heterocíclicos/síntese química , Nitroquinolinas/síntese química , Tripanossomicidas/síntese química , Aminoquinolinas/farmacologia , Compostos de Anilina/farmacologia , Animais , Antitricômonas/farmacologia , Butilaminas/farmacologia , Linhagem Celular , Compostos Heterocíclicos/farmacologia , Técnicas In Vitro , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Metronidazol/farmacologia , Nifurtimox/farmacologia , Nitroquinolinas/farmacologia , Piridinas/síntese química , Piridinas/farmacologia , Relação Estrutura-Atividade , Trichomonas vaginalis/efeitos dos fármacos , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacosRESUMO
Previous work from our laboratory showed that baclofen could lower serum prolactin (PRL) levels acting at the central nervous system. The present experiments were designed to evaluate whether the gamma-aminobutyric acid B agonist was also effective in inhibiting hormone release at the pituitary level. In monolayer cultures of adenohypophyseal dispersed cells, baclofen inhibited basal PRL secretion after 1 or 2 h of incubation. This inhibition was significantly abolished by three antagonists: phaclofen, 3-aminopropyl-phosphonic acid and 4-aminobutylphosphonic acid. Furthermore, baclofen inhibited the thyrotropin-releasing hormone-induced PRL release in a concentration-dependent manner. With regard to gonadotropin secretion, baclofen was unable to modify basal luteinizing hormone (LH) secretion, but significantly inhibited the LH-releasing hormone-induced LH release. These results show that baclofen, in addition to its central neuroendocrine effects, inhibits pituitary hormone secretion, under basal and/or stimulated conditions, by direct action at the pituitary level.