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1.
Int J Mol Sci ; 22(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34204888

RESUMO

Previously, the abundance of p42/44 and p38 MAPK proteins had been shown to be higher in arteries of 1- to 2-week-old compared to 2- to 3-month-old rats. However, the role of MAPKs in vascular tone regulation in early ontogenesis remains largely unexplored. We tested the hypothesis that the contribution of p42/44 and p38 MAPKs to the contraction of peripheral arteries is higher in the early postnatal period compared to adulthood. Saphenous arteries of 1- to 2-week-old and 2- to 3-month-old rats were studied using wire myography and western blotting. The α1-adrenoceptor agonist methoxamine did not increase the phosphorylation level of p38 MAPK in either 1- to 2-week-old or 2- to 3-month-old rats. Accordingly, inhibition of p38 MAPK did not affect arterial contraction to methoxamine in either age group. Methoxamine increased the phosphorylation level of p42/44 MAPKs in arteries of 2- to 3-month-old and of p44 MAPK in 1- to 2-week-old rats. Inhibition of p42/44 MAPKs reduced methoxamine-induced contractions in arteries of 2- to 3-month-old, but not 1- to 2-week-old rats. Thus, despite a high abundance in arterial tissue, p38 and p42/44 MAPKs do not regulate contraction of the saphenous artery in the early postnatal period. However, p42/44 MAPK activity contributes to arterial contractions in adult rats.


Assuntos
Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/genética , Contração Muscular/genética , Receptores Adrenérgicos alfa 1/genética , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Animais , Artérias/crescimento & desenvolvimento , Artérias/metabolismo , Embrião de Mamíferos , Desenvolvimento Embrionário/genética , Humanos , Metoxamina/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Liso/metabolismo , Fosforilação/efeitos dos fármacos , Ratos
2.
Prostate ; 81(7): 377-389, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33687083

RESUMO

BACKGROUND: Medical treatment in benign prostatic hyperplasia targets prostate size to prevent disease progression, complications, and surgery, and prostate smooth muscle tone for rapid relief of lower urinary tract symptoms. Combination therapies are still required to target both at once. However, current medications are insufficient, due to an unfavorable balance between side effects and efficacy. The limited efficacy of α1 -blockers may be due to nonadrenergic mediators like endothelin-1 and thromboxane A2 (TXA2 ), which keep up prostate smooth muscle contraction even in the presence of α1 -blockers. Consequently, future options with higher efficacy need to target α1 -adrenergic and nonadrenergic contractions as well as stromal cell growth at once. Thalidomide has been approved as an oral medication for various diseases, including the treatment of prostate cancer. Therefore, we investigated the effect of thalidomide on cellular functions of prostate stromal cells and human prostate smooth muscle contraction. METHODS: Cytoskeletal organization was visualized by phalloidin staining, cell growth was assessed by 5-ethynyl-2'-deoxyuridine assay, cell viability by cell counting kit-8, and apoptosis and cell death by flow cytometry in cultured prostate stromal cells (WPMY-1). Contractions of human prostate tissues from radical prostatectomy were studied in an organ bath, where they were induced by the α1 -adrenoceptor agonists methoxamine, noradrenaline, phenylephrine, and the nonadrenergic agonists endothelin-1, TXA2 analog U46619, or electric field stimulation (EFS). RESULTS: Thalidomide significantly reduced the proliferation of WPMY-1 cells, which was time- and concentration-dependent (10-300 µM). In parallel, organization of actin filaments collapsed after treatment with thalidomide. Thalidomide (30-100 µM) inhibited noradrenaline-, phenylephrine-, and methoxamine-induced contractions, as well as nonadrenergic contractions induced by endothelin-1 and U46619, and neurogenic contractions induced by EFS. No reduction in viability and no increases in apoptosis or in cell death were observed in WPMY-1 cells. CONCLUSIONS: Thalidomide impairs the growth of human prostate stromal cells, without showing a decrease in cell viability. In parallel, thalidomide inhibits adrenergic, neurogenic, and nonadrenergic contractions. This may be explained by a breakdown of the actin cytoskeleton. In vivo, urodynamic effects of thalidomide appear possible and may even exceed those of α1 -blockers or combination therapies.


Assuntos
Proliferação de Células/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Próstata/citologia , Células Estromais/efeitos dos fármacos , Talidomida/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Sintomas do Trato Urinário Inferior , Masculino , Metoxamina/farmacologia , Norepinefrina/farmacologia , Células Estromais/citologia
4.
Sci Rep ; 10(1): 20002, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33203943

RESUMO

Membrane transporters and their functional contribution in vasculature change during early postnatal development. Here we tested the hypothesis that the contribution of Cl- channels to arterial contraction declines during early postnatal development and this decline is associated with the trophic sympathetic influence. Endothelium-denuded saphenous arteries from 1- to 2-week-old and 2- to 3-month-old male rats were used. Arterial contraction was assessed in the isometric myograph, in some experiments combined with measurements of membrane potential. mRNA and protein levels were determined by qPCR and Western blot. Sympathectomy was performed by treatment with guanethidine from the first postnatal day until 8-9-week age. Cl- substitution in the solution as well as Cl--channel blockers (MONNA, DIDS) had larger suppressive effect on the methoxamine-induced arterial contraction and methoxamine-induced depolarization of smooth muscle cells in 1- to 2-week-old compared to 2- to 3-month-old rats. Vasculature of younger group demonstrated elevated expression levels of TMEM16A and bestrophin 3. Chronic sympathectomy increased Cl- contribution to arterial contraction in 2-month-old rats that was associated with an increased TMEM16A expression level. Our study demonstrates that contribution of Cl- channels to agonist-induced arterial contraction and depolarization decreases during postnatal development. This postnatal decline is associated with sympathetic nerves development.


Assuntos
Artérias/metabolismo , Canais de Cloreto/metabolismo , Contração Muscular/fisiologia , Sistema Nervoso Simpático/metabolismo , Animais , Anoctamina-1/metabolismo , Artérias/efeitos dos fármacos , Masculino , Metoxamina/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/fisiologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/fisiologia , Ratos , Ratos Wistar , Simpatectomia/métodos , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/fisiologia , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia
5.
Br J Pharmacol ; 177(22): 5148-5162, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32860629

RESUMO

BACKGROUND AND PURPOSE: The vasomotor role of K2P potassium channels during early postnatal development has never been investigated. We tested the hypothesis that TASK-1 channel (K2P family member) contribution to arterial vascular tone and BP is higher in the early postnatal period than in adulthood. EXPERIMENTAL APPROACH: We studied 10- to 15-day-old ("young") and 2- to 3-month-old ("adult") male rats performing digital PCR (dPCR) (using endothelium-intact saphenous arteries), isometric myography, sharp microelectrode technique, quantitative PCR (qPCR) and Western blotting (using endothelium-denuded saphenous arteries), and arterial pressure measurements under urethane anaesthesia. KEY RESULTS: We found mRNA of Kcnk1-Kcnk7, Kcnk12, and Kcnk13 genes to be expressed in rat saphenous artery, and Kcnk3 (TASK-1) and Kcnk6 (TWIK-2) were most abundant in both age groups. The TASK-1 channel blocker AVE1231 (1 µmol·L-1 ) prominently depolarized arterial smooth muscle and increased basal tone level and contractile responses to methoxamine of arteries from young rats but had almost no effect in adult rats. The level of TASK-1 mRNA and protein expression was higher in arteries from young compared with adult rats. Importantly, intravenous administration of AVE1231 (4 mg·kg-1 ) had no effect on mean arterial pressure in adult rats but prominently raised it in young rats. CONCLUSION AND IMPLICATIONS: We showed that TASK-1 channels are important for negative feedback regulation of vasocontraction in young but not adult rats. The influence of TASK-1 channels most likely contributes to low BP level at perinatal age.


Assuntos
Artérias , Músculo Liso Vascular , Animais , Feminino , Masculino , Metoxamina , Miografia , Proteínas do Tecido Nervoso , Canais de Potássio , Canais de Potássio de Domínios Poros em Tandem , Gravidez , Ratos
6.
BMC Anesthesiol ; 20(1): 198, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32787783

RESUMO

BACKGROUND: α-receptor agonists have been reported to be safe and effective for treating or preventing spinal-induced hypotension during cesarean delivery. As a pure α1 adrenergic agonist, methoxamine has potential advantages of reducing myocardial oxygen consumption and protecting the heart in obstetric patients compared to phenylephrine. The aim of this study was to determine the optimal prophylactic methoxamine infusion dose that would be effective for preventing spinal-induced hypotension in 50% (ED50) and 95% (ED95) of parturients. METHODS: Eighty parturients with a singleton pregnancy scheduled for elective cesarean delivery were randomly allocated to receive prophylactic methoxamine infusion at one of four different fixed-rates: 1 µg/kg/min (group M1), 2 µg/kg/min (group M2), 3 µg/kg/min (group M3), or 4 µg/kg/min (group M4). An adequate response was defined as absence of hypotension (maternal SBP < 80% of baseline or SBP < 90 mmHg). The values for ED50 and ED95 of prophylactic methoxamine infusion were determined by probit regression model. The outcomes of maternal hemodynamics and fetal status were compared among the groups. RESULTS: The calculated ED50 and ED95 (95% confidence interval) of prophylactic methoxamine infusion dose were 2.178 (95% CI 1.564 to 2.680) µg/kg/min and 4.821 (95% CI 3.951 to 7.017) µg/kg/min, respectively. The incidence of hypotension decreased with increasing methoxamine infusion dose (15/20, 11/20, 7/20 and 2/20 in group M1, M2, M3 and M4 respectively, P <  0.001). 1-min Apgar scores and umbilical arterial PaO2 were lower but umbilical arterial PaCO2 was higher in Group M1. No difference was found in the other incidence of adverse effects and neonatal outcomes among groups. CONCLUSIONS: Under the conditions of this study, when prophylactic methoxamine infusion was given at a fixed-rate based on body weight for preventing spinal-induced hypotension in obstetric patients, the values for ED50 and ED95 were 2.178 µg/kg/min and 4.821 µg/kg/min respectively. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR), registry number of clinical trial: ChiCTR-1,800,018,988 , date of registration: October 20, 2018.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 1/administração & dosagem , Anestesia Obstétrica/métodos , Cesárea/métodos , Hipotensão/prevenção & controle , Metoxamina/administração & dosagem , Profilaxia Pré-Exposição/métodos , Adulto , Cesárea/efeitos adversos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Hipotensão/diagnóstico , Infusões Intravenosas , Gravidez , Estudos Prospectivos
7.
Eur J Pharmacol ; 885: 173423, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32750368

RESUMO

In a cell line, stably expressing α1A-adrenoceptors fused to the mCherry red fluorescent protein, noradrenaline, methoxamine, and oxymetazoline induced concentration-dependent increases in intracellular calcium. All of these agents increase α1A-adrenoceptor phosphorylation and internalization. Transient co-expression of these receptors with Rab proteins tagged with the enhanced Green Fluorescent Protein was employed to estimate α1A-adrenoceptor-Rab interaction using Förster Resonance Energy Transfer. Noradrenaline and methoxamine increased α1A-adrenoceptor interaction with Rab5 and Rab7 but did not modify it with Rab9. Oxymetazoline induced adrenoceptor interaction with Rab5 and Rab9 and only an insignificant increase in Rab7 signal. Phorbol myristate acetate increased α1A-adrenoceptor interaction with Rab5 and Rab9 but did not modify it with Rab7. The agonists and the active phorbol ester, all of which induce receptor phosphorylation and internalization, favor receptor interaction with Rab5, i.e., association with early endosomes. Cell stimulation with phorbol myristate acetate induced the α1A-adrenoceptors to interact with the late endosomal marker, Rab9, suggesting that the receptors are directed to slow recycling endosomes once they have transited to the Trans-Golgi network to be retrieved to the plasma membrane. The agonists noradrenaline and methoxamine likely induce a faster recycling and might direct some of the adrenoceptors toward degradation and/or very slow recycling to the plasma membrane. Oxymetazoline produced a mixed pattern of interaction with the Rab proteins. These data indicate that α1A-adrenoceptor agonists can trigger different vesicular traffic and receptor fates within the cells.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 1/farmacologia , Ésteres de Forbol/farmacologia , Receptores Adrenérgicos alfa 1/efeitos dos fármacos , Proteínas rab de Ligação ao GTP/efeitos dos fármacos , Cálcio/metabolismo , Linhagem Celular , Endossomos/efeitos dos fármacos , Humanos , Proteínas Luminescentes , Metoxamina/farmacologia , Norepinefrina/farmacologia , Oximetazolina/farmacologia , Fosforilação , Acetato de Tetradecanoilforbol/farmacologia , Proteínas rab5 de Ligação ao GTP/efeitos dos fármacos , Rede trans-Golgi/efeitos dos fármacos
8.
Am J Otolaryngol ; 41(4): 102561, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32504853

RESUMO

OBJECTIVE: Levitra, a phosphodiesterase-5 (PDE5) inhibitor, is the trade name of vardenafil. It is applied to treatment of erectile dysfunction. PDE5 inhibitors dilate the penile blood vessels and cause prolonged erections. However, the effects of Levitra on human nasal mucosa are not yet fully explored. MATERIALS AND METHODS: We examined the effectiveness of Levitra on human nasal mucosa directly in vitro by testing: 1) effect on human nasal mucosa resting tension; 2) effect on contraction caused by 10-6 M methoxamine as a sympathetic mimetic; 3) effect of the drugs on electrically induced human nasal mucosa contractions. RESULTS: The results showed that addition of methoxamine to the incubation medium caused the nasal mucosa to contract in a dose-dependent manner. Addition of Levitra at doses of 10-4 M elicited a significant relaxation response to 10-6 M methoxamine-induced mucosa strip contraction. Levitra could not inhibit electrical field stimulation-induced spike contraction and had a minimal effect on the basal tension of nasal mucosa as the concentration increased. CONCLUSION: This study indicated that high concentrations of Levitra had a significant spasmolytic effect by antagonizing α-adrenoceptors. Moreover, nasal obstruction might not be relieved in patients suffering from erectile dysfunction and stuffy noses who were concomitant using α-adrenergic agonist and Levitra.


Assuntos
Reposicionamento de Medicamentos , Contração Isométrica/efeitos dos fármacos , Mucosa Nasal/efeitos dos fármacos , Parassimpatolíticos , Inibidores da Fosfodiesterase 5/farmacologia , Dicloridrato de Vardenafila/farmacologia , Relação Dose-Resposta a Droga , Disfunção Erétil/tratamento farmacológico , Humanos , Técnicas In Vitro , Masculino , Metoxamina/farmacologia , Obstrução Nasal/diagnóstico por imagem , Inibidores da Fosfodiesterase 5/uso terapêutico , Simpatomiméticos/farmacologia , Dicloridrato de Vardenafila/uso terapêutico
9.
BMC Anesthesiol ; 20(1): 148, 2020 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-32534584

RESUMO

BACKGROUND: Acute renal injury (AKI) caused by hypotension often occurs in elderly patients after gastrointestinal tumor surgery. Although vasoactive drugs can increase effective filtration pressure, they may increase renal vascular resistance and reduce renal blood flow. The effect of methoxamine on renal function is not clear. METHODS: After obtaining written informed consent, 180 elderly patients undergoing elective gastrointestinal tumor surgery were randomly allocated into two groups: M group (continuous infusion of methoxamine at 2 µg/kg/min) and N group (continuous infusion of normal saline). The patients' mean arterial pressure was maintained within 20% of baseline by a continuous infusion of methoxamine or normal saline. Maintenance fluid was kept at 5 mL/kg/h. According to Kidney disease improve global outcome (KDIGO) guidelines, creatinine was measured at 1, 2 and 7 days after operation, and urine volume at 6, 12 and 24 h after operation was measured to evaluate the occurrence of AKI. 162 patients were included in the final data analysis. RESULTS: Significant differences in the incidence of postoperative Acute kidney injury (M group: 7.5%; N group: 18.3%; P < 0.05), the frequency of hypotension (M group: 1 [1-3]; N group: 3 [1-5]; P < 0.05), and the duration of intraoperative hypotension (M group: 2[0-10]; N group: 10 [5-16]; P < 0.05) were identified between the groups. Multivariate logistic regression analyses demonstrated that preoperative creatinine and the frequency of intraoperative hypotension were the common factors leading to the occurrence of postoperative AKI. The results of Cox multivariate analysis showed that age and AKI were independent risk factors for 30-day death. CONCLUSION: Compared with the intraoperative continuous infusion of placebo and methoxamine, continuous infusion of 2 µg/kg/min methoxamine reduced the incidence of postoperative AKI and other clinical complications in elderly patients undergoing gastrointestinal surgery by raising blood pressure and improved the prognosis of patients. TRIAL REGISTRATION: Trial registration: Chinese Clinical Trial Registry, ChiCTR1900020536, registered 7 January, 2019.


Assuntos
Injúria Renal Aguda/prevenção & controle , Neoplasias Gastrointestinais/cirurgia , Metoxamina/administração & dosagem , Complicações Pós-Operatórias/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Pressão Arterial/efeitos dos fármacos , Método Duplo-Cego , Feminino , Humanos , Infusões Intravenosas , Período Intraoperatório , Modelos Logísticos , Masculino , Modelos de Riscos Proporcionais , Estudos Prospectivos
10.
J Chromatogr A ; 1614: 460709, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31784081

RESUMO

Steroid hormones are a type of crucial substances that mediate numerous vital physiological functions. The comprehensive detection of steroid hormones can help understand the physiopathologic mechanism of steroid hormone-related diseases. It is very difficult to determine steroid hormones in biological samples due to their low endogenous concentrations and poor ionization efficiency. In this study, an efficient and sensitive approach was developed for profiling steroid hormones by combining liquid-liquid extraction and parallel derivatization with liquid chromatography-tandem mass spectrometry. Methoxyamine and dansyl chloride were used to derivatize steroid hormones containing carbonyl and phenolic hydroxyl groups, respectively. Our established method achieved simultaneous analysis of carbonyl and phenolic hydroxyl-containing steroid hormones and could cover estrogens, androgens, corticoids and progestogens. Twenty-nine steroid hormones were detected at pg/mL levels with the sensitivity enhanced by three orders of magnitude after derivatization. The linearity (with linear range of 2-4 orders of magnitude), precision (less than 15%) and recovery (71.1-128.7%) were satisfactory for quantitative analysis of steroid hormones. Finally, the established method was successfully employed to the determination of steroid hormones in serum samples of healthy males and females as well as ovarian cancer patients. The results showed that this approach was suitable and reliable for routine test of steroid hormones containing carbonyl and phenolic hydroxyl groups.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Esteroides/química , Compostos de Dansil/química , Feminino , Humanos , Extração Líquido-Líquido , Masculino , Metoxamina/química , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/patologia , Progestinas/sangue , Progestinas/química , Progestinas/isolamento & purificação , Esteroides/sangue , Esteroides/isolamento & purificação
11.
Comput Biol Med ; 113: 103418, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31493580

RESUMO

BACKGROUND: Augmentation index (AIx) is used to quantify the augmented systolic aortic pressure that impedes ventricular ejection. Its use as an index of wave reflections is questionable. We hypothesize that AIx is quantitatively different from the reflection coefficient under varied physiological conditions. METHODS: 42 datasets of aortic pressure and flow waveforms were obtained during induced hypertension (methoxamine infusion) and vasodilation (nitroprusside infusion) in our mongrel dog experiments (n = 5) and from Mendeley data during various interventions (vasoconstrictors, vasodilators, pacing, stimulation, hemorrhage and hemodilution). Wave reflections and principal components of reflection coefficients were computed for comparison to AIx and heart rate normalized AIx. RESULTS: Principal reflection coefficient, Γ1, increased in hypertension and decreased in vasodilation, hemorrhage and hemodilution. AIx followed the trend in many cases but was consistently lower than Γ1 in almost all the subjects. The Bland-Altman analysis also showed that both AIx and normalized AIx underestimated Γ1. The relationship between augmentation index and reflection coefficient was explained by a linear regression model (r2 = 0.23, p < 0.01) in which AIx followed directional changes in Γ1 and the normalization of AIx resulted in a linear model that explained less variation in the relationship between AIx and Γ1. CONCLUSION: AIx is a reasonable clinical trend indicator, albeit not an accurate surrogate measure of the amount of wave reflections.


Assuntos
Pressão Sanguínea , Hemorragia/fisiopatologia , Hipertensão/fisiopatologia , Modelos Cardiovasculares , Sístole , Vasodilatação , Animais , Bases de Dados Factuais , Cães , Hemodiluição , Humanos , Hipertensão/induzido quimicamente , Metoxamina/efeitos adversos , Metoxamina/farmacologia , Nitroprussiato/farmacologia , Análise de Onda de Pulso
12.
Eur J Pharmacol ; 858: 172498, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31238063

RESUMO

Metformin is a widely used drug for the treatment of type 2 Diabetes Mellitus. Several studies have also suggested that metformin decreases blood pressure; although an interaction with α-adrenoceptors has been proposed, this mechanism needs to be further investigated. Since α1-adrenoceptors play a significant role to regulate vascular tone, this study has analysed the potential ability of metformin to block α1-adrenoceptors in rat aorta and tail artery. For this purpose, the contractile responses induced by noradrenaline, methoxamine, and phenylephrine were determined in the absence or presence of metformin in rat aorta and tail artery rings. In both arteries, noradrenaline, methoxamine, and phenylephrine produced concentration-dependent contractile responses. Interestingly, the contractile responses to noradrenaline, methoxamine, and phenylephrine were significantly and differentially blocked by metformin (1, 3.1 and/or 10 mM) but not by vehicle. These results suggest that metformin is capable to block α1-adrenoceptors and may explain, at least in part, the anti-hypertensive effect observed in several clinical trials.


Assuntos
Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Aorta/efeitos dos fármacos , Aorta/fisiologia , Metformina/farmacologia , Receptores Adrenérgicos alfa 1/metabolismo , Cauda/irrigação sanguínea , Animais , Masculino , Metoxamina/farmacologia , Fenilefrina/farmacologia , Ratos , Ratos Wistar , Vasoconstrição/efeitos dos fármacos
13.
Eur Arch Otorhinolaryngol ; 276(3): 761-765, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30604060

RESUMO

OBJECTIVE: Montelukast is a selective and orally active leukotriene D4 receptor antagonist often used in treating asthma and allergic rhinitis. Montelukast nasal spray was developed to avoid systemic adverse effects of the drug in vitro. However, the effects of montelukast on human nasal mucosa are not yet fully explored and potential nasal vascular side effects of the drug merit further exploration. First, the effects of montelukast on vasocontractile responses generated by smooth muscles in the vascular structures of human nasal mucosa were investigated directly in vitro. METHODS: This study examined the effects of montelukast on human nasal mucosa in terms of mucosa resting tension, vasoconstriction caused by 10- 6 M methoxamine as a sympathetic mimetic, and electrically induced vasoconstrictions. RESULTS: The results indicated that addition of methoxamine to the incubation medium caused the nasal mucosa to vasocontract in a dose-dependent manner. Addition of montelukast at doses of 10- 5 M or above elicited a significant vasodilation response to 10- 6 M methoxamine-induced vasoconstriction. Montelukast could not inhibit electrical field stimulation-induced spike vasoconstriction. Moreover, increase in concentration of montelukast had minimal effect on basal tension of nasal mucosa. CONCLUSIONS: The study indicated significant vasodilation on human nasal mucosa under high concentrations of montelukast with a probable α-adrenoceptor antagonism. Hence, the nasal activity of α-adrenergic agonist nasal spray for nasal obstruction may be reduced in those using concomitant (oral or local spray) montelukast.


Assuntos
Acetatos/farmacologia , Antiasmáticos/farmacologia , Antagonistas de Leucotrienos/farmacologia , Músculo Liso/efeitos dos fármacos , Mucosa Nasal/efeitos dos fármacos , Quinolinas/farmacologia , Ciclopropanos , Estimulação Elétrica , Humanos , Técnicas In Vitro , Metoxamina/farmacologia , Músculo Liso/irrigação sanguínea , Sprays Nasais , Sulfetos , Vasoconstrição , Vasoconstritores/farmacologia
14.
Pediatr Res ; 84(1): 112-117, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29795210

RESUMO

BACKGROUND: Maternal thyroid deficiency can increase Rho-kinase procontractile influence in arteries of 2-week-old progeny. Here we hypothesized that augmented role of Rho-kinase persists in arteries from adult progeny of hypothyroid rats. METHODS: Dams were treated with 6-propyl-2-thiouracil (PTU) in drinking water (0.0007%) during pregnancy and 2 weeks postpartum; control (CON) females received PTU-free water. At the age of 10-12-weeks, serum T3/T4 levels did not differ between PTU and CON male offspring. Cutaneous (saphenous), mesenteric, and skeletal muscle (sural) arteries were studied by wire myography, qPCR, and Western blotting. RESULTS: Saphenous arteries of PTU and CON groups showed similar responses to α1-adrenoceptor agonist methoxamine and were equally suppressed by Rho-kinase inhibitor Y27632. Responses of mesenteric arteries also did not differ between PTU and CON, but the effects of Y27632 were more prominent in the PTU group. Sural arteries of PTU rats compared to CON demonstrated augmented responses to methoxamine, increased RhoA mRNA contents and higher levels of MYPT1 phosphorylation at Thr855. Intergroup differences in contractile responses and phospho-MYPT1-Thr855 were eliminated by Y27632. CONCLUSION: Rho-kinase contribution to contractile responses of mesenteric and especially sural arteries is augmented in adult PTU rats. Therefore, maternal thyroid deficiency may have long-term detrimental consequences for vasculature in adult offspring.


Assuntos
Hipotireoidismo/metabolismo , Artérias Mesentéricas/fisiologia , Contração Muscular , Complicações na Gravidez/metabolismo , Hormônios Tireóideos/deficiência , Quinases Associadas a rho/metabolismo , Amidas , Animais , Peso Corporal , Feminino , Masculino , Metoxamina/química , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/patologia , Músculo Liso Vascular , Fosforilação , Gravidez , Prenhez , Propiltiouracila/química , Piridinas , Ratos , Ratos Wistar
15.
Acta Physiol (Oxf) ; 223(3): e13044, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29383848

RESUMO

AIM: During early post-natal development, arterial contraction depends less on Ca2+ -signalling pathways but more on changes in Ca2+ -sensitivity compared to adult animals. Whether this difference is related to Rho-kinase, one of the major players affecting Ca2+ -sensitivity, is unknown for intact vessels. Thus, we tested the hypothesis that Rho-kinase critically contributes to the higher Ca2+ -sensitivity of contraction in intact arteries of 1-week-old rats. METHODS: We studied 1-week-old, 4- to 5-week-old and 10- to 12-week-old rats performing isometric myography, Ca2+ -fluorimetry and Western blotting using intact saphenous arteries and arterial pressure measurements under urethane anaesthesia. RESULTS: In 10- to 12-week-old rats, methoxamine (MX) produced vasoconstriction associated with an increase in [Ca2+ ]i and Ca2+ -sensitivity. In contrast, in 1-week-old rats these contractions were accompanied only by an increase in Ca2+ -sensitivity. All MX-induced effects were reduced by the Rho-kinase inhibitor Y-27632; this reduction was complete only in 1-week-old rats. The Rho-kinase specific site Thr855 on MYPT1 was increasingly phosphorylated by MX in vessels of 1-week-old, but not 10- to 12-week-old rats; this effect was also inhibited completely by Y-27632. The Rho-kinase inhibitor fasudil in a dose not affecting the pressor response to MX in 4- to 5-week-old rats reduced it considerably in 1-week-old rats. CONCLUSION: Our results suggest that the higher Ca2+ -sensitivity of arterial contraction in 1-week-old compared to 10- to 12-week-old rats is due to a greater Rho-kinase activity. Constitutively active Rho-kinase contributes to MX-induced contraction in 10- to 12-week-old rats. In 1-week-old rats, additional Rho-kinase activation is involved. This remodelling of the Rho-kinase pathway is associated with its increased contribution to adrenergic arterial pressure responses.


Assuntos
Envelhecimento/metabolismo , Artérias/fisiologia , Sinalização do Cálcio , Vasoconstrição , Quinases Associadas a rho/metabolismo , Animais , Masculino , Metoxamina , Músculo Liso Vascular/metabolismo , Proteína Quinase C/metabolismo , Ratos Wistar
16.
Eur J Pharmacol ; 820: 130-137, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29248426

RESUMO

It has been reported that metformin reduces blood pressure although the mechanisms have not been described. Indeed, several mechanisms could be implicated including the interaction with α-adrenoceptors or inhibition of sympathetic outflow. Therefore, this study was designed to determine the capability of metformin to block the vasopressor responses induced by α1/2-adrenoceptor agonists or selective electrical stimulation of sympathetic outflow. For this purpose, Wistar male rats were anesthetized, pithed and cannulated for selective preganglionic stimulation of the vasopressor sympathetic outflow or drugs administration. The effect of i.v. bolus injection of metformin (180 and 310mg/kg) or its vehicle (bidistilled water) was studied on the vasopressor responses induced by: (1) selective sympathetic stimulation (0.03-3Hz); (2) exogenous noradrenaline (0.03-3µg/kg); (3) methoxamine (1-100µg/kg); and (4) UK 14,304 (0.1-30µg/kg). The tachycardic responses to noradrenaline were also investigated in presence of metformin. The vasopressor responses induced by selective electrical stimulation of sympathetic outflow were diminished by metformin (180 and 310mg/kg) and remained unchanged in presence of vehicle. Moreover, the vasopressor responses induced by exogenous noradrenaline, methoxamine and UK 14,304 were dose-dependently inhibited by i.v. bolus injections of metformin (180 and 310mg/kg) and were not affected by vehicle. Metformin practically did not block the tachycardic responses to noradrenaline except at the dose of 3µg/kg. Taken together, these results demonstrate that metformin is capable to block vascular α1/2-adrenoceptors but not cardiac ß-adrenoceptors. Thus, this mechanism could contribute, at least in part, on the hypotensive responses induced by metformin.


Assuntos
Anti-Hipertensivos/farmacologia , Metformina/farmacologia , Receptores Adrenérgicos alfa 1/metabolismo , Receptores Adrenérgicos alfa 2/metabolismo , Animais , Anti-Hipertensivos/uso terapêutico , Tartarato de Brimonidina/farmacologia , Relação Dose-Resposta a Droga , Hemodinâmica/efeitos dos fármacos , Masculino , Metformina/uso terapêutico , Metoxamina/farmacologia , Norepinefrina/farmacologia , Ratos , Ratos Wistar , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/fisiologia , Taquicardia/induzido quimicamente , Taquicardia/tratamento farmacológico
17.
Channels (Austin) ; 12(1): 9-14, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-28991505

RESUMO

The spinal cord contains specialized groups of cells called pattern generators, which are capable of orchestrating rhythmic firing activity in an isolated preparation. Different patterns of activity could be generated in vitro including right-left alternating bursting and bursting in which both sides are synchronized. The cellular and network mechanisms that enable these behaviors are not fully understood. We have recently shown that Ca2+-activated K+ channels (SK channels) control the initiation and amplitude of synchronized bursting in the spinal cord. It is unclear, however, whether SK channels play a similar role in the alternating rhythmic pattern. In the current study, we used a spinal cord preparation from functionally mature mice capable of weight bearing and walking. The present results extend our previous work and show that SK channel inhibition initiates and modulates the amplitude of alternating bursting. We also show that addition of methoxamine, an α1-adrenergic agonist, to a cocktail of serotonin, dopamine, and NMDA evokes robust and consistent alternating bursting throughout the cord.


Assuntos
Locomoção/efeitos dos fármacos , Metoxamina/farmacologia , Canais de Potássio Cálcio-Ativados/antagonistas & inibidores , Medula Espinal/efeitos dos fármacos , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos , Canais de Potássio Cálcio-Ativados/metabolismo , Medula Espinal/metabolismo
18.
Sci Rep ; 7(1): 16734, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29196668

RESUMO

Current induction methods of hepatocytes from human induced pluripotent stem cells (hiPSCs) are neither low cost nor stable. By screening a chemical library of 1,120 bioactive compounds and known drugs, we identified the α1-adrenergic receptor agonist methoxamine hydrochloride as a small molecule that promotes the differentiation of hiPSC-derived hepatoblasts into ALBUMIN+ hepatocyte-like cells. Other α1-adrenergic receptor agonists also induced the differentiation of hepatocyte-like cells, and an α1-receptor antagonist blocked the hepatic-inducing activity of methoxamine hydrochloride and that of the combination of hepatocyte growth factor (HGF) and Oncostatin M (OsM), two growth factors often used for the induction of hepatoblasts into hepatocyte-like cells. We also confirmed that treatment with methoxamine hydrochloride activates the signal transducer and activator of transcription 3 (STAT3) pathway downstream of IL-6 family cytokines including OsM. These findings allowed us to establish hepatic differentiation protocols for both mouse embryonic stem cells (mESCs) and hiPSCs using small molecules at the step from hepatoblasts into hepatocyte-like cells. The results of the present study suggest that α1-adrenergic agonists induce hepatocyte-like cells by working downstream of HGF and OsM to activate STAT3.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 1/farmacologia , Hepatócitos/citologia , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Metoxamina/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Fator de Crescimento de Hepatócito/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Células-Tronco Embrionárias Humanas/efeitos dos fármacos , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Oncostatina M/farmacologia , Fator de Transcrição STAT3/metabolismo , Albumina Sérica Humana/metabolismo , Transdução de Sinais/efeitos dos fármacos
19.
BMC Anesthesiol ; 17(1): 75, 2017 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-28599629

RESUMO

BACKGROUND: Postoperative cognitive dysfunction (POCD), common in elderly patients, is thought to be closely associated with intraoperative instability of hemodynamics and excessive excretion of tumor necrosis factor-α (TNF-α). Methoxamine is a blood-pressure increasing drug commonly used for maintaining intraoperative hemodynamics. Methoxamine potentially promotes TNF-α expression, leading to an increased risk of POCD. This study aimed to investigate the dose-dependent effect of methoxamine on the incidence of early POCD and blood TNF-α level. METHODS: This single-center prospective double-blind controlled clinical trial included a total of 300 adult patients (75-90 years old, American Society of Anesthesiologists class II-III) who underwent unilateral hip-joint replacement surgery under epidural anesthesia. Patients were randomly divided into three methoxamine groups (M1, M2, and M3), and one control group (n = 75 per group). During surgery, M1, M2, and M3 patients received intravenous infusion of methoxamine at 2, 3, or 4 µg·kg-1·min-1, respectively; the control group received saline of same volume at the same infusion rate. All patients received standard transfusion to maintain stable circulation. Hemodynamics, cardiovascular events, and serum TNF-α levels were monitored. Mini Mental State Examination was performed both before and after surgery to diagnose POCD. RESULTS: The primary outcome of this study was the incidence of POCD, which was higher in the M3 group (18.7%) than in the control group (5.3%), the M1 group (6.7%), or the M2 group (6.7%) (all P < 0.05). The secondary outcomes were the postoperative blood TNF-α level and intraoperative hemodynamic parameters. The postoperative TNF-α level was found to be higher than baseline in all groups and was highest in M3 patients (P < 0.05). The intraoperative hemodynamic parameters showed improved stability in the M1 and M2 groups compared with the control group. However, in the M3 group, abnormally increased intraoperative blood pressure, cardiac output, and systolic stroke volume were observed. CONCLUSIONS: Intravenous infusion of methoxamine at 2-3 µg·kg-1·min-1 can maintain stable hemodynamics in elderly patients during epidural anesthesia for hip-joint replacement surgery, without increasing the incidence of POCD. Increasing the dose to 4 µg·kg-1·min-1 provided no further advantages but induced adverse effects on the intraoperative hemodynamics. TRIAL REGISTRATION: Chinese Clinical Trial Register (Unique identifier: ChiCTR-INR-15007607 , retrospectively registered 18 Dec 2015).


Assuntos
Disfunção Cognitiva/induzido quimicamente , Metoxamina/efeitos adversos , Complicações Pós-Operatórias/induzido quimicamente , Fator de Necrose Tumoral alfa/sangue , Vasoconstritores/efeitos adversos , Idoso de 80 Anos ou mais , Anestesia Epidural , Artroplastia de Quadril , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Infusões Intravenosas , Masculino , Metoxamina/administração & dosagem , Estudos Prospectivos , Volume Sistólico/efeitos dos fármacos , Vasoconstritores/administração & dosagem
20.
Br J Pharmacol ; 174(14): 2318-2333, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28444738

RESUMO

BACKGROUND AND PURPOSE: Agonists acting at GPCRs promote biased signalling via Gα or Gßγ subunits, GPCR kinases and ß-arrestins. Since the demonstration of biased agonism has implications for drug discovery, it is essential to consider confounding factors contributing to bias. We have examined bias at human α1A -adrenoceptors stably expressed at low levels in CHO-K1 cells, identifying off-target effects at endogenous receptors that contribute to ERK1/2 phosphorylation in response to the agonist oxymetazoline. EXPERIMENTAL APPROACH: Intracellular Ca2+ mobilization was monitored in a Flexstation® using Fluo 4-AM. The accumulation of cAMP and ERK1/2 phosphorylation were measured using AlphaScreen® proximity assays, and mRNA expression was measured by RT-qPCR. Ligand bias was determined using the operational model of agonism. KEY RESULTS: Noradrenaline, phenylephrine, methoxamine and A61603 increased Ca2+ mobilization, cAMP accumulation and ERK1/2 phosphorylation. However, oxymetazoline showed low efficacy for Ca+2 mobilization, no effect on cAMP generation and high efficacy for ERK1/2 phosphorylation. The apparent functional selectivity of oxymetazoline towards ERK1/2 was related to off-target effects at 5-HT1B receptors endogenously expressed in CHO-K1 cells. Phenylephrine and methoxamine showed genuine bias towards ERK1/2 phosphorylation compared to Ca2+ and cAMP pathways, whereas A61603 displayed bias towards cAMP accumulation compared to ERK1/2 phosphorylation. CONCLUSION AND IMPLICATIONS: We have shown that while adrenergic agonists display bias at human α1A -adrenoceptors, the marked bias of oxymetazoline for ERK1/2 phosphorylation originates from off-target effects. Commonly used cell lines express a repertoire of endogenous GPCRs that may confound studies on biased agonism at recombinant receptors.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 1/farmacologia , Imidazóis/farmacologia , Metoxamina/farmacologia , Norepinefrina/farmacologia , Fenilefrina/farmacologia , Receptores Adrenérgicos alfa 1/metabolismo , Tetra-Hidronaftalenos/farmacologia , Agonistas de Receptores Adrenérgicos alfa 1/química , Animais , Células CHO , Células Cultivadas , Cricetulus , Relação Dose-Resposta a Droga , Humanos , Imidazóis/química , Metoxamina/química , Norepinefrina/química , Fenilefrina/química , Relação Estrutura-Atividade , Tetra-Hidronaftalenos/química
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