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2.
Zhonghua Yi Xue Za Zhi ; 100(17): 1320-1325, 2020 May 05.
Artigo em Chinês | MEDLINE | ID: mdl-32375440

RESUMO

Objective: To explore the effect of phenolamine on the outcome and prognosis of patients with myocardial injury due to sepsis. Methods: From January 2015 to December 2017, 62 septic patients with myocardial injury were randomly divided into study group (n=32) and control group (n=30). Two groups were given conventional treatment, while the study group was treated with phentolamine. The NT-pro brain natriuretic pepitide (NT-proBNP), cardiac troponin I (cTnI), lactate dehydrogenase (LDH), creatine kinase isoenzymes (CK-MB) and tumor necrosis factor (TNF)-α, high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-1ß, IL-6 were detected at 0,12, 24, 48, 72 h and 7 d after hospitalization. And left ventricular ejection fraction (LVEF), e', E and A in each time period were observed. The 28 d survival rate and length of ICU stay were observed in both groups. The data were compared with single sample t test between the two groups. Results: After 12, 24, 48, 72 h and 7 d, NT-proBNP, cTnI, LDH, CK-MB, TNF-α, hs-CRP, IL-1ß, IL-6 in the study group were all significantly lower than those in the control group (all P<0.05). The cardiac function indexes of LVEF, E/A and E/e' in the study group were all significantly improved when compared with those in the control group (all P<0.05). The length of ICU stay and 28-day mortality in the study group were significantly lower than those in the control group ((9.8±3.6) d vs (13.0±4.1) d, t=3.152, P=0.004; 21.9% vs 36.7%, χ(2)=5.078, P=0.021). Conclusion: Combined application of phentolamine can significantly improve the outcome of sepsis patients with myocardial injury and improve the survival rate.


Assuntos
Fentolamina/uso terapêutico , Sepse , Humanos , Peptídeo Natriurético Encefálico , Prognóstico , Sepse/tratamento farmacológico , Volume Sistólico , Função Ventricular Esquerda
4.
Quintessence Int ; 50(7): 568-575, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31134227

RESUMO

OBJECTIVE: To systematically review the safety of phentolamine mesylate as a reversal agent for pulpal and soft tissue dental anesthesia. DATA SOURCES: Comprehensive search, up to August 2018, was performed in three major electronic databases. The methodologic quality of all the included studies was assessed using Cochrane Collaboration for randomized clinical trials. RESULTS: A total of nine studies were included for qualitative and quantitative assessment. The number of events was 269 in 2,057 participants in the phentolamine mesylate group, and 179 in 1,338 participants of the control group (odds ratio 1.19; 95% confidence interval 1.03 to 1.39). In the data segregated based on age, four studies conducted on children and adolescents revealed an odds ratio of 0.68, whereas two studies on adults revealed an odds ratio of 1.58. CONCLUSION: There were no severe complications reported in any of the included studies, but the occurrence of adverse events (mild and moderate) was greater in the phentolamine mesylate group compared to the control group. Age has a significant effect on the possibility of adverse events with phentolamine mesylate.


Assuntos
Antagonistas Adrenérgicos alfa , Anestesia Dentária , Adolescente , Adulto , Anestésicos Locais , Criança , Humanos , Fentolamina , Fatores de Tempo
5.
Anesth Analg ; 128(6): 1336-1343, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31094809

RESUMO

BACKGROUND: The objective of the experiment was to assess the antinociceptive effect of dibucaine, bupivacaine, and epinephrine. To assess the mechanism of action of the interaction between dibucaine and epinephrine, phentolamine, a nonselective α-adrenergic antagonist, was added to the mixture. METHODS: We assessed sensory blockade with these drugs by injecting 0.6 mL of drug-in-saline in the dorsal thoracolumbar area of rats; pinprick of the "wheal" formed by the injectate was the area targeted for stimulation to elicit a cutaneous trunci muscle reflex. The sensory block of dibucaine was compared with that of bupivacaine or epinephrine. Drug-drug interactions were analyzed by isobologram. Phentolamine was added to investigate the antinociceptive effect of dibucaine coinjected with epinephrine. RESULTS: We demonstrated that dibucaine, epinephrine, and bupivacaine produced dose-dependent skin antinociception. On the median effective dose (ED50) basis, the potency was higher for epinephrine (mean, 0.011 [95% confidence interval {CI}, 0.007-0.015] µmol) than for dibucaine (mean, 0.493 [95% CI, 0.435-0.560] µmol) (P < .01), while there were no significant differences between dibucaine and bupivacaine (mean, 0.450 [95% CI, 0.400-0.505] µmol). On the equipotent basis (75% effective dose, median effective dose, and 25% effective dose), sensory block duration provoked by epinephrine was greater (P < .01) than that provoked by dibucaine or bupivacaine. Coadministration of dibucaine with epinephrine produced a synergistic nociceptive block, whereas phentolamine blocked that synergistic block. CONCLUSIONS: The preclinical data indicated that there is no statistically significant difference between the potency and duration of dibucaine and bupivacaine in this model. Epinephrine synergistically enhances the effects of dibucaine, while phentolamine partially blocked those effects. α-Adrenergic receptors play an important role in controlling synergistic analgesic effect of dibucaine combined with epinephrine.


Assuntos
Antagonistas Adrenérgicos alfa/farmacologia , Analgésicos/farmacologia , Bupivacaína/farmacologia , Dibucaína/farmacologia , Epinefrina/farmacologia , Fentolamina/farmacologia , Pele/efeitos dos fármacos , Analgesia , Anestésicos Locais/farmacologia , Animais , Área Sob a Curva , Relação Dose-Resposta a Droga , Interações Medicamentosas , Sinergismo Farmacológico , Injeções Subcutâneas , Masculino , Dor/tratamento farmacológico , Ratos , Ratos Sprague-Dawley
6.
World J Urol ; 37(6): 1007-1014, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30895359

RESUMO

PURPOSE: Data assessing the effectiveness of intracavernosal injections (ICIs) for the treatment of erectile dysfunction (ED) are limited. This study evaluates intracavernosal injectable therapies for ED and reviews available guidelines that inform clinical practice. METHODS: A systematic search using electronic databases (Medline, Pubmed) was performed for studies investigating injectable management strategies for ED published after 1990. Primary outcome measures were to comparatively evaluate clinical efficacy, continuation rates and adverse event profiles of each injectable agent as monotherapy or in combination. The secondary outcome measurement was to discuss available guidelines that inform clinical practice for injectable agents. RESULTS: ICIs demonstrate clinical efficacy in 54-100% of patients, early discontinuation rates of ≤ 38% and adverse events in ≤ 26%. Discontinuation rates are typically greatest within 3-6 months of commencement. Anxiety related to the initial injection occurs in approximately 65% and anxiety levels can remain high for 4 months. Approval of intracavernosal injection agents is mainly limited to alprostadil with the recent addition of aviptadil/phentolamine combination therapy in a select few geographical regions. Although combination therapies are attractive alternative options, their formulations are variable and should be standardised before widespread acceptance is achieved. CONCLUSIONS: ICIs are associated with good clinical efficacy rates, high discontinuation rates and a moderate side-effect profile. They represent an important tool in the urological armamentarium for treating ED in patients that cannot tolerate or are refractory to oral therapies.


Assuntos
Alprostadil/administração & dosagem , Disfunção Erétil/tratamento farmacológico , Fentolamina/administração & dosagem , Peptídeo Intestinal Vasoativo/administração & dosagem , Vasodilatadores/administração & dosagem , Combinação de Medicamentos , Humanos , Injeções Intralesionais , Masculino , Pênis
7.
J Coll Physicians Surg Pak ; 29(3): 231-234, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30823948

RESUMO

OBJECTIVE: To investigate the effect of magnesium sulfate combined with phentolamine and nifedipine for the treatment of gestational hypertension and on the levels of serum LIF and Apelin. STUDY DESIGN: An experimental study. PLACE AND DURATION OF STUDY: Obstetrics and Gynecology Clinics, The Affiliated Hospital North China University of Science and Technology, China, from September 2016 to February 2018. METHODOLOGY: One hundred and sixty patients with gestational hypertension were randomly divided into a control group and an observation group, 80 patients in each group. Control group was given magnesium sulfate alone, while observation group was added with phentolamine and nifedipine on the basis of the treatment in control group. Curative effects, pregnancy outcomes, and levels of serum LIF and Apelin were compared. RESULTS: The total effective rate of treatment in the observation group was higher than that in the control group (p=0.005). After treatment, level of serum LIF in the observation group was higher than that in the control group (p<0.001), and level of serum Apelin in the observation group was lower than that in the control group (p<0.001). Incidence of premature birth, cesarean section and neonatal asphyxia in the observation group were all lower than those in the control group (p=0.005, p<0.001 and p=0.005, respectively), while there was no significant difference in the incidence of neonatal death between the two groups (p=0.316). CONCLUSION: Magnesium sulfate combined with phentolamine and nifedipine has a better therapeutic effect on gestational hypertension, which can effectively regulate the levels of serum LIF and Apelin and improve pregnancy outcomes.


Assuntos
Apelina/sangue , Hipertensão Induzida pela Gravidez/diagnóstico , Hipertensão Induzida pela Gravidez/tratamento farmacológico , Fator Inibidor de Leucemia/sangue , Sulfato de Magnésio/uso terapêutico , Fentolamina/uso terapêutico , Resultado da Gravidez , Adulto , Biomarcadores/sangue , China , Quimioterapia Combinada , Feminino , Seguimentos , Idade Gestacional , Humanos , Gravidez , Estudos Prospectivos , Medição de Risco
8.
Bull Exp Biol Med ; 166(3): 313-316, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30680492

RESUMO

Changes in the pulmonary microcirculation in isolated perfused rabbit lungs during modeling of pulmonary thromboembolism were studied in control animals and against the background of α-adrenoceptors blockade with phentolamine. Intravenous injection of emboli to control animals was followed by an increase in pressure in the pulmonary artery, mean capillary hydrostatic pressure, capillary filtration coefficient, pulmonary vascular resistance, as well as precapillary and postcapillary resistances. Against the background of α-adrenoceptor blockade, the increase in most parameters was less pronounced than in control animals, while capillary filtration coefficient increased more drastically. Thus, adrenergic mechanisms are involved in the constrictor reactions of both arterial and venous pulmonary vessels under conditions of pulmonary thromboembolism.


Assuntos
Antagonistas Adrenérgicos alfa/farmacologia , Pulmão/efeitos dos fármacos , Microcirculação/efeitos dos fármacos , Fentolamina/farmacologia , Embolia Pulmonar/tratamento farmacológico , Receptores Adrenérgicos alfa/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Permeabilidade Capilar/efeitos dos fármacos , Modelos Animais de Doenças , Pulmão/irrigação sanguínea , Pulmão/metabolismo , Pulmão/fisiopatologia , Técnicas de Cultura de Órgãos , Perfusão , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/metabolismo , Artéria Pulmonar/fisiopatologia , Embolia Pulmonar/metabolismo , Embolia Pulmonar/fisiopatologia , Veias Pulmonares/efeitos dos fármacos , Veias Pulmonares/metabolismo , Veias Pulmonares/fisiopatologia , Coelhos , Resistência Vascular/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos
9.
Psychoneuroendocrinology ; 105: 44-50, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30318393

RESUMO

BACKGROUND: Stress-induced prothrombotic changes are mediated by the sympathetic nervous system and critically involved in mental triggering of acute coronary syndromes, but the underlying psychobiology is not fully understood. We tested the hypothesis that a norepinephrine (NE) infusion to mimic effects of stress-induced NE release on blood coagulation elicits prothrombotic changes and examined to what extent these would be mediated by an alpha-adrenergic mechanism. METHODS AND RESULTS: In a single-blind placebo-controlled within-subjects design, 24 middle-aged, non-smoking, non-obese and normotensive men participated in three experimental trials with an interval between one and two weeks. Each trial applied two sequential infusions of 1 and 15 min duration with varying substances [i.e., saline as placebo, the non-specific α-blocker phentolamine (2.5 mg/min), and NE (5 µg/min)]: trial 1=saline + saline; trial 2=saline + NE, and trial 3=phentolamine + NE. Plasma levels of clotting factor VIII activity (FVIII:C), fibrinogen, and D-dimer were assessed from blood samples collected immediately before and 1 min and 20 min after infusion procedures. Compared to saline + saline, saline + NE induced increases over time in FVIII:C, fibrinogen, and D-dimer levels. With phentolamine + NE, fibrinogen levels remained increased compared to saline + saline, but changes in FVIII:C and D-dimer levels were no more different. Coagulation changes did not differ between saline + NE and phentolamine + NE. CONCLUSIONS: NE infusion activates blood coagulation. The resulting prothrombotic state could be one psychobiological mechanism underlying mental triggering of acute coronary syndromes. Blockade of α-adrenergic receptors partly attenuated NE effects on coagulation and could be implied to have preventive potential in susceptible individuals.


Assuntos
Agonistas alfa-Adrenérgicos/farmacologia , Antagonistas Adrenérgicos alfa/farmacologia , Fatores de Coagulação Sanguínea/efeitos dos fármacos , Coagulação Sanguínea/efeitos dos fármacos , Norepinefrina/sangue , Norepinefrina/farmacologia , Fentolamina/farmacologia , Estresse Psicológico/sangue , Agonistas alfa-Adrenérgicos/administração & dosagem , Antagonistas Adrenérgicos alfa/administração & dosagem , Adulto , Epinefrina/sangue , Fator VIII/efeitos dos fármacos , Produtos de Degradação da Fibrina e do Fibrinogênio/efeitos dos fármacos , Fibrinogênio/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/administração & dosagem , Fentolamina/administração & dosagem , Método Simples-Cego
10.
PLoS One ; 13(9): e0203573, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30199552

RESUMO

Endothelium is the main source of catecholamine release in the electrical-field stimulation (EFS)-induced aortic contractions of the non- venomous snake Panterophis guttatus. However, adrenergic vasomotor control in venomous snakes such as Crotalus durissus terrificus and Bothrops jararaca has not yet been investigated. Crotalus and Bothrops aortic rings were mounted in an organ bath system. EFS-induced aortae contractions were performed in the presence and absence of guanethidine (30 µM), phentolamine (10 µM) or tetrodotoxin (1 µM). Frequency-induced contractions were also performed in aortae with endothelium removed. Immunohistochemical localization of both tyrosine hydroxylase (TH) and S-100 protein in snake aortic rings and brains, as well as in human tissue (paraganglioma tumour) were carried out. EFS (4 to 16 Hz) induced frequency-dependent aortic contractions in both Crotalus and Bothrops. The EFS-induced contractions were significantly reduced in the presence of either guanethidine or phentolamine in both snakes (p<0.05), whereas tetrodotoxin had no effect in either. Removal of the endothelium abolished the EFS-induced contractions in both snakes aortae (p<0.05). Immunohistochemistry revealed TH localization in endothelium of both snake aortae and human vessels. Nerve fibers were not observed in either snake aortae. In contrast, both TH and S100 protein were observed in snake brains and human tissue. Vascular endothelium is the main source of catecholamine release in EFS-induced contractions in Crotalus and Bothrops aortae. Human endothelial cells also expressed TH, indicating that endothelium- derived catecholamines possibly occur in mammalian vessels.


Assuntos
Aorta/efeitos dos fármacos , Bothrops/metabolismo , Catecolaminas/metabolismo , Crotalus/metabolismo , Estimulação Elétrica , Animais , Catecolaminas/farmacologia , Endotélio Vascular/efeitos dos fármacos , Guanetidina/metabolismo , Guanetidina/farmacologia , Técnicas In Vitro , Fentolamina/metabolismo , Fentolamina/farmacologia , Proteínas S100/metabolismo , Tetrodotoxina/metabolismo , Tetrodotoxina/farmacologia , Tirosina 3-Mono-Oxigenase/metabolismo
11.
J Insect Physiol ; 109: 144-148, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30077702

RESUMO

Cannibalism has been observed occasionally in a limited number of different animal species, but the underlying mechanisms that foster this behavior are mostly unknown. Here we show that mosquito (Culex pipiens) larvae show this behavior towards conspecifics under certain conditions. Cannibalism was only observed in 4th instar larvae and only in response to starvation. Well fed animals never showed any cannibalistic behavior. Starvation induced cannibalism of Culex 4th instar was predominantly directed towards 3rd instars rather than to 1st or 2nd instar larvae. Specific mandibular structures of these larvae enable this cannibalistic behavior. We could show that treatment with the biogenic amine octopamine, which is known to be involved in the control of starvation and aggression, increased the rate of cannibalism of food-deprived 4th instar larvae significantly. Incubation with the octopamine receptor antagonist phentolamine suppressed this cannibalistic behavior. Moreover, octopamine not only increased the rate of cannibalism, it also induced a shift towards smaller prey. A role of octopamine in this starvation induced behavior was further supported by direct measurements of the total content of this important neuroactive compound. Taken together, we could show that 4th instar mosquito larvae showed cannibalistic behavior after starvation and that this behavior apparently depends on octopamine.


Assuntos
Canibalismo , Culex/fisiologia , Privação de Alimentos , Animais , Comportamento Animal/efeitos dos fármacos , Culex/efeitos dos fármacos , Culex/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Larva/fisiologia , Octopamina/farmacologia , Fentolamina/administração & dosagem , Comportamento Predatório/efeitos dos fármacos
12.
Psychosom Med ; 80(7): 649-658, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29965944

RESUMO

OBJECTIVE: Acute stress induces redistribution of circulating leucocytes in humans. Although effects on lymphocytes as adaptive immune cells are well understood, the mechanisms underlying stress effects on granulocytes and monocytes as innate immune blood cells are still elusive. We investigated whether the stress hormone norepinephrine (NE) and α-adrenergic receptors (α-ADRs) may play a mediating role. METHODS: In a stress study, we cross-sectionally tested 44 healthy men for associations between stress-induced NE increases and simultaneous granulocyte and monocyte cell count increases, as measured immediately before and several times after the Trier Social Stress Test. In a subsequent infusion study, 21 healthy men participated in three different experimental trials with sequential infusions of 1- and 15-minute duration with varying substances (saline as placebo, the nonspecific α-ADR blocker phentolamine [2.5 mg/min], and NE [5 µg/min]): trial 1 = saline+saline, trial 2 = saline+NE, trial 3 = phentolamine+NE. Granulocyte and monocyte cell numbers were assessed before, immediately after, 10 minutes, and 30 minutes after infusion procedures. RESULTS: In the stress study, higher NE related to higher neutrophil stress changes (ß = .31, p = .045, R change = .09), but not epinephrine stress changes. In the infusion study, saline+NE induced significant increases in neutrophil (F(3/60) = 43.50, p < .001, η = .69) and monocyte (F(3/60) = 18.56, p < .001, η = .48) numbers compared with saline+saline. With phentolamine+NE, neutrophil (F(3/60) = 14.41, p < .001, η = .42) and monocyte counts (F(2.23/44.6) = 4.32, p = .016, η = .18) remained increased compared with saline+saline but were lower compared with saline+NE (neutrophils: F(3/60) = 19.55, p < .001, η = .494, monocytes: F(3/60) = 2.54, p = .065, η = .11) indicating partial mediation by α-ADRs. Trials did not differ in eosinophil and basophil count reactivity. CONCLUSIONS: Our findings suggest that NE-induced immediate increases in neutrophil and monocyte numbers resemble psychosocial stress effects and can be reduced by blockade of α-ADRs.


Assuntos
Antagonistas Adrenérgicos alfa/farmacologia , Granulócitos/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Norepinefrina/farmacologia , Receptores Adrenérgicos alfa/efeitos dos fármacos , Estresse Psicológico , Adulto , Idoso , Estudos Transversais , Humanos , Masculino , Pessoa de Meia-Idade , Fentolamina/farmacologia , Estresse Psicológico/induzido quimicamente , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Adulto Jovem
13.
Pestic Biochem Physiol ; 148: 175-181, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29891370

RESUMO

Rhinella icterica is a poisonous toad whose toxic secretion has never been studied against entomotoxic potential. Sublethal doses of Rhinella icterica toxic secretion (RITS) were assayed in Nauphoeta cinerea cockroaches, in order to understand the physiological and behavioral parameters, over the insect central and peripheral nervous system. RITS (10 µg/g) injections, induced behavioral impairment as evidenced by a significant decrease (38 ±â€¯14%) in the distance traveled (p < .05), followed by an increase (90 ±â€¯6%) of immobile episodes (p < .001, n = 28, respectively). In cockroaches semi-isolated heart preparations, RITS (16 µg/200 µl) induced a significant irreversible dose-dependent negative chronotropism, reaching ~40% decrease in heart rate in 20 min incubation. In in vivo cockroach neuromuscular preparations, RITS (20, 50 and 100 µg/g of animal weight) induced a time-dependent inhibition of twitch tension that was complete for 20 µg/g, in 120 min recordings. RITS (10 µg/g) also induced a significant increase in the insect leg grooming activity (128 ±â€¯10%, n = 29, p < .01), but not in the antennae counterparts. The RITS increase in leg grooming activity was prevented in 90% by the pretreatment of cockroaches with phentolamine (0.1 µg/g). The electrophysiological recordings of spontaneous neural compound action potentials showed that RITS (20 µg/g) induced a significant increase in the number of events, as well as in the rise time and duration of the potentials. In conclusion, RITS showed to be entomotoxic, being the neuromuscular failure and cardiotoxic activity considered the main deleterious effects. The disturbance of the cockroaches' behavior together with the electrophysiological alterations, may unveil the presence of some toxic components present in the poison with inherent biotechnological potentials.


Assuntos
Bufonidae/fisiologia , Baratas/efeitos dos fármacos , Octopamina/farmacologia , Pele/metabolismo , Toxinas Biológicas/toxicidade , Potenciais de Ação/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Baratas/metabolismo , Relação Dose-Resposta a Droga , Asseio Animal/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Técnicas In Vitro , Junção Neuromuscular/efeitos dos fármacos , Octopamina/metabolismo , Fentolamina/farmacologia , Toxinas Biológicas/metabolismo
14.
J Evid Based Dent Pract ; 18(2): 181-184, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29747805

RESUMO

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Effectiveness and safety of phentolamine mesylate in routine dental care. Daubländer M, Liebaug F, Niedeggen G, Theobald K, Kürzinger M-L. J Am Dent Assoc 2017; 148(3):149-56. SOURCE OF FUNDING: The study was funded by Sanofi-Aventis Deutschland, Berlin, Germany TYPE OF STUDY/DESIGN: Two study designs were used: a prospective noninterventional, postauthorization efficacy (controlled observational) study, and a prospective noninterventional uncontrolled observational study.


Assuntos
Anestesia Dentária , Anestesia Local , Antagonistas Adrenérgicos alfa , Período de Recuperação da Anestesia , Anestésicos Locais , Assistência Odontológica , Humanos , Fentolamina , Estudos Prospectivos
15.
PLoS One ; 13(4): e0196123, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29672643

RESUMO

A tetrodotoxin (TTX)-resistant mechanism is responsible for the electrical field stimulation (EFS)-induced contractions and relaxations of Crotalus durissus terrificus corpora cavernosa. Here it was investigated whether this mechanism also occurs in corpora cavernosa and aortae of the non-venomous snake Pantherophis guttatus corpora cavernosa and aortae. Corpora cavernosa and aortic rings isolated from Pantherophis guttatus snake were mounted in organ bath system for isometric tension recording. EFS-induced contractions in both tissues were performed in the presence and absence of guanethidine (30 µM), phentolamine (10 µM) and tetrodotoxin (1 µM). In another set of experiments, the endothelium was removed from aortic rings and EFS-induced contractions were performed in the denuded rings. Electrical field stimulation-induced contractions were frequency-dependent in Pantherophis guttatus corpora cavernosa and aortic rings. The contractions were significantly reduced in the presence of guanethidine (30 µM) or phentolamine (10 µM). Pre-treatment with tetrodotoxin had no effect on the EFS-induced contractions of either corpora cavernosa or aortic rings. Surprisingly, the EFS-induced contractions of aortic rings denuded of endothelium were almost abolished. These results indicate that the TTX-resistant mechanism is present in EFS-induced contractions of Pantherophis guttatus corpora cavernosa and aortae. The experiments performed in the aorta indicate that the endothelium is the main source for the release of catecholamines induced by EFS.


Assuntos
Estimulação Elétrica , Contração Muscular , Serpentes/fisiologia , Acetilcolina/farmacologia , Animais , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Contração Muscular/efeitos dos fármacos , Fentolamina/farmacologia , Tetrodotoxina/farmacologia
16.
J Dent ; 72: 76-79, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29571953

RESUMO

OBJECTIVES: Prolonged soft tissue anesthesia following a dental appointment is a complaint that is frequently reported by patients. Soft tissue anesthesia generally exceeds the duration of pulpal anesthesia by a few hours. This can lead to difficulties with smiling, drinking, speaking and lip/cheek biting following dental appointments. Phentolamine Mesylate (PM) is a pharmacological agent capable of reducing the duration of soft tissue anesthesia following dental treatments. Many clinical trials supporting its efficacy have used sham injections compared to injections with PM. The present study aims to evaluate the effect of PM on the duration of soft tissue anesthesia compared to a control injection of saline water. METHODS: This randomized controlled trial recruited 40 participants above 18 years of age. Following an inferior alveolar nerve block using 1.8 ml of Lidocaine 2%, 1:100 000 epinephrine, participants were randomized into one of 2 groups. The test group received an injection of 0.4 mg PM (OraVerse). Participants in the control group received an injection of sterile saline water. Participants were trained in self-assessing their anesthesia, which they did until return to normal sensation. RESULTS: Thirty-six participants completed the study. PM significantly reduced the duration of soft tissue anesthesia in the lower lip (104 vs 170 min, p = .001), and tongue (83 vs 134 min, p = .004) compared to the control injection. No serious adverse events were encountered. The only adverse events observed were post-operative pain and discomfort. CONCLUSIONS: Phentolamine Mesylate hastens the return to normal soft tissue sensation and function by approximately one hour compared to a control injection of water. CLINICAL SIGNIFICANCE: Phentolamine Mesylate can be considered a safe and effective way of reducing the duration of soft tissue anesthesia following a dental appointment. This controlled clinical trial is registered at the National Institutes of Health (ClinicalTrials.gov) #NCT02861378.


Assuntos
Anestesia Dentária/métodos , Anestésicos Locais/administração & dosagem , Lidocaína/administração & dosagem , Lidocaína/antagonistas & inibidores , Adulto , Anestesia Local/métodos , Epinefrina , Humanos , Injeções , Lábio/efeitos dos fármacos , Bloqueio Nervoso , Dor Pós-Operatória/etiologia , Fentolamina/administração & dosagem , Fentolamina/farmacologia , Fatores de Tempo , Língua/efeitos dos fármacos
17.
Physiol Res ; 67(2): 275-282, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29303604

RESUMO

Electric stimulation (ES) could induce contraction of intestinal smooth muscle. The aim of this study was to analyze the effects of ES on esophageal motility and the underlying mechanism in vivo. Twenty-eight rabbits were equipped with a pair of subserosa electrodes (connected to an electrical stimulator) in the lower segment of the esophagus. The ES signal consisted of bipolar rectangular pulse trains, lasting for 3 s, with different amplitudes (1 mA, 3 mA, 5 mA and 10 mA), and frequencies (10 Hz, 20 Hz and 50 Hz). The amplitude of the contraction was recognized by high-resolution manometry. The effect of ES was tested under anesthesia and following administration of atropine, phentolamine or L-NAME. ES induced esophageal contraction at the stimulated site. A statistically significant increase in esophageal pressure was observed when the stimulation amplitude was above 3 mA. The increase in esophageal pressure was associated with the amplitude of stimulus as well as the frequency. During stimulation, atropine, phentolamine and L-NAME had no effect on the increase of esophageal pressure induced by ES. These findings implied that ES induced esophageal contraction were not mediated via the NANC, adrenergic or cholinergic pathway. The amplitude of esophageal contraction was current and frequency dependent.


Assuntos
Estimulação Elétrica , Esôfago/fisiologia , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Atropina/farmacologia , Transtornos da Motilidade Esofágica/fisiopatologia , Esôfago/efeitos dos fármacos , Motilidade Gastrointestinal/efeitos dos fármacos , Motilidade Gastrointestinal/fisiologia , Masculino , Manometria , Antagonistas Muscarínicos/farmacologia , Contração Muscular , NG-Nitroarginina Metil Éster/farmacologia , Fentolamina/farmacologia , Coelhos
18.
Pestic Biochem Physiol ; 151: 53-58, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30704713

RESUMO

G-Protein-Coupled Receptors (GPCRs) are an underdeveloped target in the search for agrochemicals with octopamine receptors, a GPCR, being the target of a single insecticide/acaricide class (formamidines). The evolution of insecticide resistance has resulted in the need to identify new or underutilized targets for the development of agrochemicals, with the goal of controlling arthropod pests that affect agriculture or human and animal health. The insect cholinergic system has been a fruitful target for the development of insecticides/acaricides viz. acetylcholinesterase inhibitors and agonists/modulators of the nicotinic acetylcholine receptor. However, the muscarinic acetylcholine receptors (mAChRs), which are GPCRs, have not been successfully developed as a target for agrochemicals. Others have recently identified three subtypes of insect mAChRs in Drosophila melanogaster, and extracellular recordings from transected D. melanogaster larval central nervous system (CNS) were performed to investigate the electrogenesis of the octopaminergic and muscarinic systems. Octopamine (10 µM) resulted in a sustained neuroexcitation during a 30 min exposure, and neuroexcitation after 21 min was blocked by octopamine receptor antagonist, phentolamine (100 µM). Exposure of this preparation to the non-selective mAChR agonist, pilocarpine (10 µM), resulted in a biphasic response, characterized by neuroexcitation followed by a decrease in the CNS firing rate below initial control levels. This biphasic effect was antagonized by the classical mAChR antagonist atropine (10 µM). It was also found that atropine (10 µM) blocked octopamine's sustained neuroexcitation, indicating the possibility of cross-talk between these two GPCR pathways.


Assuntos
Drosophila melanogaster/metabolismo , Larva/metabolismo , Octopamina/farmacologia , Receptores Acoplados a Proteínas-G/metabolismo , Animais , Atropina/farmacologia , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/metabolismo , Colforsina/farmacologia , CMP Cíclico/análogos & derivados , CMP Cíclico/metabolismo , Drosophila melanogaster/efeitos dos fármacos , Eletrofisiologia , Larva/efeitos dos fármacos , Fentolamina/farmacologia , Pilocarpina/farmacologia
20.
Eur J Pain ; 22(3): 572-582, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29226500

RESUMO

BACKGROUND: ß-Blockers reduce temporomandibular joint (TMJ) pain. We asked whether they also reduce TMJ inflammation and, if so, whether this anti-inflammatory effect contributes to its analgesic action. METHODS: We measured many parameters of the inflammatory response after co-administration of the ß-blocker propranolol with the inflammatory agent carrageenan in the TMJ of female rats. We also hypothesized that the activation of ß-adrenoceptors in the TMJ induces nociception mediated, at least in part, by the inflammatory response. To test this hypothesis, we examined the nociceptive response induced by the activation of the ß-adrenoceptors in the TMJ in female rats pretreated with thalidomide and fucoidan. RESULTS: We found that the co-administration of propranolol with carrageenan in the TMJ of female rats significantly reduced several parameters of the inflammatory response induced by carrageenan such as plasma extravasation, neutrophil migration and the release of the pro-inflammatory cytokines TNF-α, IL-1ß and CINC-1. Furthermore, the injection of the ß-adrenergic receptor agonist isoproterenol in the TMJ induced nociception that was significantly reduced by thalidomide, fucoidan and by the co-administration of propranolol but not of the α-adrenergic receptor antagonist phentolamine. CONCLUSIONS: Propranolol has anti-inflammatory effects that contribute to its antinociceptive action in the TMJ of females. SIGNIFICANCE: ß-Blockers have an anti-inflammatory effect on temporomandibular joint (TMJ) that contributes to its analgesic effect. The results of this work suggest that ß-blockers can be used to treat the painful conditions of TMJ, especially when they are associated with an inflammatory process.


Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Nociceptividade/efeitos dos fármacos , Propranolol/farmacologia , Articulação Temporomandibular/efeitos dos fármacos , Antagonistas Adrenérgicos alfa/farmacologia , Analgésicos/uso terapêutico , Animais , Anti-Inflamatórios/uso terapêutico , Anticoagulantes/farmacologia , Carragenina/farmacologia , Quimiocina CXCL1/efeitos dos fármacos , Quimiocina CXCL1/imunologia , Feminino , Imunossupressores/farmacologia , Interleucina-1beta/efeitos dos fármacos , Interleucina-1beta/imunologia , Dor/tratamento farmacológico , Medição da Dor/efeitos dos fármacos , Fentolamina/farmacologia , Polissacarídeos/farmacologia , Ratos , Ratos Wistar , Articulação Temporomandibular/imunologia , Transtornos da Articulação Temporomandibular/tratamento farmacológico , Talidomida/farmacologia
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