RESUMO
The aim of the present study was to evaluate the central antinociceptive effects of eugenol after intraperitoneal administration. Experiments were carried out using male Sprague-Dawley rats. Subcutaneous injection of 5% formalin-induced nociceptive behavioral responses was used as the pain model. Subcutaneous injection of 5% formalin significantly produced nociceptive responses by increasing the licking time during nociceptive behavior. Subsequent intraperitoneal injection of 100 mg/kg of eugenol led to a significant decrease in the licking time. However, low dose of eugenol (50 mg/kg) did not affect the nociceptive behavioral responses produced by subcutaneous injection of formalin. Intrathecal injection of 30 µg of naloxone, an opioid receptor antagonist, significantly blocked antinociceptive effects produced by intraperitoneal injection of eugenol. Neither intrathecal injection of methysergide (30 µg), a serotonin receptor antagonist nor phentolamine (30 µg), an α-adrenergic receptor antagonist influenced antinociceptive effects of eugenol, as compared to the vehicle treatment. These results suggest that central opioid pathway participates in mediating the antinociceptive effects of eugenol.
Assuntos
Humanos , Masculino , Eugenol , Formaldeído , Injeções Intraperitoneais , Injeções Espinhais , Injeções Subcutâneas , Metisergida , Naloxona , Negociação , Fentolamina , Ratos Sprague-Dawley , Receptores Opioides , SerotoninaRESUMO
<p><b>Objective</b>To investigate the application value of Toshiba 320-row dynamic volumetric CT angiography in the diagnosis of venous erectile dysfunction (VED).</p><p><b>METHODS</b>We enrolled in this study 33 patients diagnosed with ED by audiovisual sexual stimulation screening in the outpatient department. Penile erection was induced in the patients by injection of 2 mg phentolamine plus 30 mg papaverine into the corpus cavernosum, followed by that of contrast agent of iobitridol through the vein and corpus cavernosum successively. Then 320-row dynamic volumetric CT angiography was performed and the images of the corpus cavernosum in the arterial and venous phases were collected and processed.</p><p><b>RESULTS</b>Different degrees of abnormal venous drainage were observed in 29 of the patients, including 7 cases (24.1%) of back deep venous leakage, 6 cases (20.7%) of foot venous leakage, 3 cases (10.3%) of dorsal superficial venous leakage, 1 case (3.5%) of intervertebral venous leakage, 2 cases (6.9%) of cavernous venous leakage, and 10 cases (34.5%) of mixed venous leakage. Ten of the patients underwent surgery, dorsal deep penile vein ligation in 2 cases, dorsal deep vein embedding plus foot vein ligation in 4, and foot vein ligation in the other 4. Eight of the patients were followed up for 3-12 months post-operatively, during which 2 achieved obvious erectile improvement, while the other 6 gained normal penile erection.</p><p><b>CONCLUSIONS</b>Toshiba 320-row dynamic volumetric CT angiography is a reliable method for the diagnosis of VED, which displays the precise location of venous leakage for clinical treatment, with the advantages of clearer images, lower doses of contrast agent and radiation, and faster examination than X-ray penile angiography.</p>
Assuntos
Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Artérias , Diagnóstico por Imagem , Angiografia por Tomografia Computadorizada , Meios de Contraste , Combinação de Medicamentos , Disfunção Erétil , Diagnóstico por Imagem , Injeções , Iohexol , Ligadura , Papaverina , Ereção Peniana , Pênis , Diagnóstico por Imagem , Fentolamina , Veias , Diagnóstico por Imagem , Cirurgia GeralRESUMO
BACKGROUND AND OBJECTIVES: Painful phenomenon is one of the most important and complex experiences. Phentolamine is a non-selective alpha-adrenergic antagonist. The objective of this study was to compare the effect of increasing doses of phentolamine into subarachnoid space in rats in the modulation of painful phenomenon. METHODS: 84 male Wistar rats were divided into formalin and plantar incision groups, subdivided into six subgroups (n = 7). Control group received only saline (10 µL); active subgroups received phentolamine 10 µmg (GF10), 20 mg (GF20), 30 mg (GF30), 40 mg (GF40), and 50 g (GF50). In formalin group, pain was induced by injection of 50 µL of 2% formalin in dorsal region of right posterior paw. In plantar incision group, pain was induced by plantar incision and evaluated using von Frey filaments. Induction and maintenance of anesthesia were performed with 3% halothane for catheter placement into subarachnoid space and plantar incision. Statistical analysis was performed using the JMP program from SAS with 5% significance level. RESULTS: Phentolamine at doses of 20 and 30 g increased the algesic response in the intermediate phase of the formalin test. In plantar incision test, it had hyperalgic effect on first, third, fifth, and seventh days at a dose of 10 g and on first, third, and fifth days at a dose of 20 g and on fifth day at a dose of 30 g. CONCLUSION: Subarachnoid administration of phentolamine showed hyperalgesic effect, possibly due to the involvement of different subclasses of alpha-adrenergic receptors in modulating pain pathways. .
JUSTIFICATIVA E OBJETIVOS: O fenômeno doloroso é uma das mais importantes e complexas experiências. A fentolamina é antagonista alfa-adrenérgico não seletivo. O objetivo foi comparar os efeitos de doses crescentes da fentolamina, por via subaracnóidea, em ratos na modulação do fenômeno doloroso. MÉTODO: Foram usados 84 ratos Wistar machos, divididos nos grupos formalina e incisão plantar, subdivididos em seis subgrupos (n = 7). No subgrupo controle (GC) apenas salina (10 µL), nos subgrupos ativos, 10 µg de fentolamina (GF10), 20 µg (GF20), 30 µg (GF30), 40 µg (GF40) e 50 µg (GF50). No grupo formalina, a dor foi induzida com injeção de 50 µL de formalina a 2%, na região dorsal da pata posterior direita. No grupo incisão plantar, a dor foi induzida por incisão plantar e avaliação pelos filamentos de Von Frey. Indução e manutenção anestésica com halotano a 3% para introdução de cateter no espaço subaracnóideo e feitura da incisão plantar. Análise estatística dos resultados pelo programa JMP do SAS com nível de significância 5%. RESULTADOS: A fentolamina nas doses de 20 e 30 µg produziu aumento da resposta álgica na fase intermediária do teste da formalina. No teste da incisão plantar, promoveu efeito hiperálgico no primeiro, terceiro, quinto e sétimo dias na dose de 10 µg, no primeiro, terceiro e quinto dias na dose de 20 µg e no quinto dia na dose de 30 µg. CONCLUSÃO: A fentolamina por via subaracnóidea promoveu efeito hiperálgico, possivelmente pela participação de diferentes subclasses de receptores alfa-adrenérgicos nas vias modulatórias da dor. .
JUSTIFICACIÓN Y OBJETIVOS: El fenómeno doloroso es una de las más importantes y complejas experiencias. La fentolamina es un antagonista alfaadrenérgico no selectivo. El objetivo fue comparar los efectos de dosis crecientes de fentolamina por vía subaracnoidea en la modulación del fenómeno doloroso en ratones. MÉTODO: Fueron usados 84 ratones Wistar machos, divididos en los grupos formalina e incisión plantar, subdivididos en 6 subgrupos (n = 7). En el subgrupo control (GC) solamente se administró solución salina (10 µL); en los subgrupos activos, 10 µg de fentolamina (GF10), 20 µg (GF20), 30 µg (GF30), 40 µg (GF40) y 50 µg (GF50). En el grupo formalina, el dolor fue inducido con una inyección de 50 µL de formalina al 2% en la región dorsal de la pata posterior derecha. En el grupo incisión plantar, el dolor se indujo por incisión plantar y evaluación por los filamentos de Von Frey. La inducción y el mantenimiento anestésico se llevó a cabo con halotano al 3% para la introducción de catéter en el espacio subaracnoideo y la realización de la incisión plantar. El análisis estadístico de los resultados se hizo mediante el programa JMP(r) del SAS con un nivel de significación del 5%. RESULTADOS: La fentolamina en las dosis de 20 y 30 µg produjo un aumento de la respuesta de dolor en la fase intermedia del test de la formalina. En el test de la incisión plantar, generó un efecto hiperalgésico en el primero, tercero, quinto y séptimo días con dosis de 10 µg; en el primero, tercero y quinto días con dosis de 20 µg; y en el quinto día con dosis de 30 µg. CONCLUSIÓN: La fentolamina por vía subaracnoidea generó un efecto hiperalgésico posiblemente por la participación de diferentes subclases de receptores alfaadrenérgicos en las vías moduladoras del dolor. .
Assuntos
Animais , Ratos , Fentolamina/farmacologia , Medição da Dor/métodos , Sudorese GustativaRESUMO
Taurine (2-aminoethanesulfonic acid) is widely distributed in animal tissues and has diverse pharmacological effects. However, the role of taurine in modulating smooth muscle contractility is still controversial. We propose that taurine (5-80 mM) can exert bidirectional modulation on the contractility of isolated rat jejunal segments. Different low and high contractile states were induced in isolated jejunal segments of rats to observe the effects of taurine and the associated mechanisms. Taurine induced stimulatory effects on the contractility of isolated rat jejunal segments at 3 different low contractile states, and inhibitory effects at 3 different high contractile states. Bidirectional modulation was not observed in the presence of verapamil or tetrodotoxin, suggesting that taurine-induced bidirectional modulation is Ca2+ dependent and requires the presence of the enteric nervous system. The stimulatory effects of taurine on the contractility of isolated jejunal segments was blocked by atropine but not by diphenhydramine or by cimetidine, suggesting that muscarinic-linked activation was involved in the stimulatory effects when isolated jejunal segments were in a low contractile state. The inhibitory effects of taurine on the contractility of isolated jejunal segments were blocked by propranolol and L-NG-nitroarginine but not by phentolamine, suggesting that adrenergic β receptors and a nitric oxide relaxing mechanism were involved when isolated jejunal segments were in high contractile states. No bidirectional effects of taurine on myosin phosphorylation were observed. The contractile states of jejunal segments determine taurine-induced stimulatory or inhibitory effects, which are associated with muscarinic receptors and adrenergic β receptors, and a nitric oxide associated relaxing mechanism.
Assuntos
Animais , Masculino , Jejuno/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Miosinas/metabolismo , Taurina/farmacologia , Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Atropina/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Cimetidina/farmacologia , Difenidramina/farmacologia , Sistema Nervoso Entérico/efeitos dos fármacos , Antagonistas dos Receptores Histamínicos H1/farmacologia , /farmacologia , Jejuno/fisiologia , Antagonistas Muscarínicos/farmacologia , Quinase de Cadeia Leve de Miosina/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico/metabolismo , Fosforilação , Fentolamina/farmacologia , Propranolol/farmacologia , Ratos Sprague-Dawley , Taurina/antagonistas & inibidores , Tetrodotoxina/farmacologia , Verapamil/farmacologiaRESUMO
This study assessed the roles of chronic stress (CS) in the stimulation of the sympathetic nervous system and explored the underlying mechanisms of periodontitis. Using an animal model of periodontitis and CS, the expression of tyrosine hydroxylase (TH) and the protein levels of the alpha1-adrenergic receptor (alpha1-AR) and beta2-adrenergic receptor (beta2-AR) were assessed. Furthermore, human periodontal ligament fibroblasts (HPDLFs) were stimulated with lipopolysaccharide (LPS) to mimic the process of inflammation. The proliferation of the HPDLFs and the expression of alpha1-AR and beta2-AR were assessed. The inflammatory-related cytokines interleukin (IL)-1beta, IL-6 and IL-8 were detected after pretreatment with the alpha1/beta2-AR blockers phentolamine/propranolol, both in vitro and in vivo. Results show that periodontitis under CS conditions enhanced the expression of TH, alpha1-AR and beta2-AR. Phentolamine significantly reduced the inflammatory cytokine levels. Furthermore, we observed a marked decrease in HPDLF proliferation and the increased expression of alpha1-ARfollowing LPS pretreatment. Pretreatment with phentolamine dramatically ameliorated LPS-inhibited cell proliferation. In addition, the blocking of alpha1-ARsignaling also hindered the upregulation of the inflammatory-related cytokines IL-1beta, IL-6 and IL-8. These results suggest that CS can significantly enhance the pathological progression of periodontitis by an alpha1-adrenergic signaling-mediated inflammatory response. We have identified a potential therapeutic target for the treatment of periodontal disease, particularly in those patients suffering from concurrent CS.
Assuntos
Animais , Humanos , Masculino , Ratos , Antagonistas de Receptores Adrenérgicos alfa 1/uso terapêutico , Células Cultivadas , Citocinas/imunologia , Fibroblastos/imunologia , Lipopolissacarídeos/administração & dosagem , Ligamento Periodontal/citologia , Periodontite/tratamento farmacológico , Fentolamina/uso terapêutico , Ratos Wistar , Receptores Adrenérgicos alfa 1/análise , Transdução de Sinais/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/análiseRESUMO
<p><b>OBJECTIVE</b>To study the effect of urapidil combined with phentolamine in the management of hypertension during extracorporeal circulation.</p><p><b>METHODS</b>Ninety patients undergoing aortic and mitral valve replacement were randomly divided into 3 equal groups to receive treatment with phentolamine (group A), urapidil (group B), or both (group C) during extracorporeal circulation. The mean arterial pressure (MAP) before and after drug administration, time interval of two administrations, spontaneous recovery of heart beat after aorta unclamping, ventricular arrhythmia, changes of ST-segment 1 min after the recovery of heart beat, ante-parallel cycle time, aorta clamping time, post-parallel cycle time, dopamine dose after cardiac resuscitation, and perioperative changes of plasma TNF-α and IL-6 levels were recorded.</p><p><b>RESULTS</b>There was no significant difference in MAP between the 3 groups before or after hypotensive drug administration (P>0.05). The time interval of two hypotensive drug administrations was longer in group C than in groups A and B (P<0.05). The incidence of spontaneous recovery of heart beat after aorta unclamping, incidence of ventricular arrhythmia, changes of ST-segment 1 min after the recovery of heart beat, ante-parallel cycle time, aorta clamping time, and post-parallel cycle time were all comparable between the 3 groups. The dose of dopamine administered after cardiac resuscitation was significantly larger in group B than in groups A or group C (P<0.05). The plasma levels of TNF-α and IL-6 were significantly increased after CPB and after the operation in all the groups, but were lowed in group C than in groups A and B at the end of CPB and at 2 h and 12 after the operation.</p><p><b>CONCLUSIONS</b>Urapidil combined with phentolamine can control hypertension during extracorporeal circulation without causing hypotension.</p>
Assuntos
Humanos , Circulação Extracorpórea , Frequência Cardíaca , Hipertensão , Interleucina-6 , Sangue , Fentolamina , Usos Terapêuticos , Piperazinas , Usos Terapêuticos , Fator de Necrose Tumoral alfa , SangueRESUMO
In this study, we propose that diprophylline exerts bidirectional modulation (BM) on the isolated rat jejunal segment depending on its contractile state. The results supported the hypothesis. Diprophylline (20 microM) exerted stimulatory effects on the contractility of jejunal segment in six low contractile states while inhibitory effects in six high contractile states, showing the characteristics of BM. Diprophylline-induced stimulatory effect was significantly blocked by atropine, indicating the correlation with cholinergic activation. Diprophylline-induced inhibitory effect was partially blocked by phentolamine, propranolol, and L-N-Nitro-Arginine respectively, indicating their correlation with sympathetic activation and nitric oxide-mediated relaxing mechanisms. Diprophylline-induced BM was abolished by tetrodotoxin or in a Ca2+ free condition or pretreated with tyrosine kinase inhibitor imatinib, suggesting that diprophylline-induced BM is Ca2+ dependent, and that it requires the presence of enteric nervous system as well as pacemaker activity of interstitial cells of Cajal. Diprophylline significantly increased the reduced MLCK expression and myosin extent in constipation-prominent rats and significantly decreased the increased MLCK expression and myosin extent in diarrhea-prominent rats, suggesting that the change of MLCK expression may also be involved in diprophylline-induced BM on rat jejunal contractility. In summary, diprophylline-exerted BM depends on the contractile states of the jejunal segments, requires the presence of Ca2+, enteric nervous system, pacemaker activity of interstitial cells of Cajal, and MLCK-correlated myosin phosphorylation. The results suggest the potential implication of diprophylline in relieving alternative hypo/hyper intestinal motility.
Assuntos
Animais , Ratos , Atropina , Difilina , Sistema Nervoso Entérico , Motilidade Gastrointestinal , Células Intersticiais de Cajal , Miosinas , Fentolamina , Fosforilação , Propranolol , Proteínas Tirosina Quinases , Tetrodotoxina , Mesilato de ImatinibRESUMO
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).This article has been retracted at the request of the journal Editorial Office.The authors have plagiarized part of a paper that had already appeared in Chinese Journal of Arteriosclerosis 2014, 4, 362–366. article id: 1007–3949 (2014) 22-04-0362-05. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.
Assuntos
Animais , Masculino , Ratos , Antagonistas Adrenérgicos alfa , Farmacologia , Cardiomegalia , Metabolismo , Colágeno Tipo I , Metabolismo , Matriz Extracelular , Metabolismo , Coração , Metaloproteinases da Matriz , Metabolismo , Miocárdio , Metabolismo , Fentolamina , Farmacologia , Ratos Sprague-Dawley , Remodelação VentricularRESUMO
FUNDAMENTO: A presença de nervos nas válvulas cardíacas foi demonstrada pela primeira vez há décadas e identificadas em subpopulações: simpáticas e parassimpáticas, e, portanto, é esperado que as válvulas sejam grandemente afetadas pelos nervos autônomos. Entretanto, poucos estudos têm se concentrado na regulação de válvulas cardíacas pelo sistema nervoso autônomo. OBJETIVO: Buscamos identificar o papel do sistema nervoso autônomo na regulação das propriedades mecânicas dos tecidos de válvulas mitrais porcinas. MÉTODOS: As propriedades mecânicas dos folhetos de válvulas mitrais porcinas foram avaliados em resposta à norepinefrina (NE) e acetilcolina (ACH), os principais neurotransmissores. Ao mesmo tempo, fentolamina (FENT), metoprolol (Metop), atropina (Atrop) e desnudamento endotelial foram adicionados ao sistema reativo. RESULTADOS: Sob condições fisiológicas, a rigidez não foi afetada pelo desnudamento endotelial (p > 0,05). A NE significantemente aumentou a rigidez valvar por aumento de 10 vezes na concentração (10-6 vs 10-7, p < 0,05; 10-5 vs 10-6, p < 0,05). Essa resposta foi amenizada por FENT, Metop ou desnudamento endotelial (p < 0,05); entretanto, manteve-se aumentada de maneira significante quando comparada aos Controles (p < 0,05). A ACH causou uma diminuição na rigidez acompanhada por um aumento em sua concentração (alteração significante na rigidez por aumento de 10 vezes na concentração de ACH, 10-6 vs Controle, p < 0,05; 10-5 vs 10-6, p < 0,05), que foi revertida pelo desnudamento endotelial e Atrop (p > 0,05 vs Controle). CONCLUSÃO: Esses achados ressaltam o papel do sistema nervoso autônomo na regulação das propriedades mecânicas das cúspides de válvula mitral porcina, o que reforça a importância do estado nervoso autônomo no funcionamento ideal da válvula.
BACKGROUND: The presence of nerves in heart valves was first depicted decades ago and identified into subpopulations: sympathetic, parasympathetic. So valves are expected to be greatly affected by the autonomic nerves. However, few studies have focused on the regulation of heart valves by the autonomic nervous system. OBJECTIVE: We sought to identify the role of the autonomic nervous system in the regulation of the mechanical properties of porcine mitral valve tissues. METHODS: Mechanical properties of porcine mitral valve leaflets were evaluated in response to norepinephrine (NE) and acetylcholine (ACH), the main neurotransmitters. At the same time, phentolamine (Phent), metoprolol (Metop), atropine (Atrop) and endothelial denudation were added to the reactive system. RESULTS: Under physiological conditions, the stiffness was not affected by endothelial denudation (p > 0.05). NE elevated the valve stiffness significantly per 10-fold increase in concentration (10-6 vs 10-7, p < 0.05; 10-5 vs 10-6, p < 0.05). This response was mitigated by Phent, Metop or endothelial denudation (p < 0.05), however, it was still increased significantly when compared to Controls (p < 0.05). ACH caused a decrease in stiffness accompanied by an increase in its concentration (significant change in stiffness per 10-fold increase in ACH concentration, 10-6 vs Control, p < 0.05; 10-5 vs 10-6, p < 0.05), which were reversed by endothelial denudation and Atrop (p > 0.05 vs Control). CONCLUSION: These findings highlight the role of the autonomic nervous system in the regulation of the mechanical properties of porcine mitral valve cusps, which underline the importance of autonomic nervous status for optimal valve function.
FUNDAMENTO: La presencia de nervios en las válvulas cardíacas quedó demostrada por primera vez hace algunas décadas e identificadas en sub-poblaciones: simpáticas y parasimpáticas y por lo tanto, lo que se espera es que las válvulas reciban una gran afectación de los nervios autónomos. Sin embargo, pocos estudios se han concentrado en la regulación de válvulas cardíacas a través del sistema nervioso autónomo. OBJETIVO: Buscamos identificar el papel del sistema nervioso autónomo en la regulación de las propiedades mecánicas de los tejidos de las válvulas mitrales porcinas. MÉTODOS: Las propiedades mecánicas de las capas de válvulas mitrales porcinas fueron evaluadas en respuesta a la norepinefrina (NE) y a la acetilcolina (ACH), los principales neurotransmisores. Igualmente, la fentolamina (FENT), el metoprolol (Metop), la atropina (Atrop) y la denudación endotelial también se añadieron al sistema reactivo. RESULTADOS: Bajo condiciones fisiológicas, la rigidez no se afectó por el denudación endotelial (p > 0,05). La NE aumentó significativamente la rigidez valvular con un aumento de 10 veces en la concentración (10-6 vs 10-7, p < 0,05; 10-5 vs 10-6, p < 0,05). Esa respuesta fue amenizada por FENT, Metop o denudación endotelial (p < 0,05); pero se mantuvo aumentada de manera significativa cuando se le comparó con los Controles (p < 0,05). La ACH causó una disminución en la rigidez acompañada por un aumento en su concentración (alteración significativa en la rigidez por el aumento en 10 veces de la concentración de ACH, 10-6 vs Control, p < 0,05; 10-5 vs 10-6, p < 0,05), que fue revertida por la denudación endotelial y Atrop (p > 0,05 vs Control). CONCLUSIÓN: Esos hallazgos destacan el rol del sistema nervioso autónomo en la regulación de las propiedades mecánicas de las cúspides de la válvula mitral porcina, lo que refuerza la importancia del estado nervioso autónomo en el funcionamiento ideal de la válvula.
Assuntos
Animais , Sistema Nervoso Autônomo/fisiologia , Valva Mitral/fisiologia , Análise de Variância , Acetilcolina/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Valva Aórtica/fisiopatologia , Sistema Nervoso Autônomo/efeitos dos fármacos , Tecido Elástico/fisiologia , Valva Mitral/inervação , Norepinefrina/farmacologia , Fentolamina/farmacologia , Receptores de Neurotransmissores/efeitos dos fármacos , Receptores de Neurotransmissores/fisiologia , Suínos , Rigidez Vascular/efeitos dos fármacos , Rigidez Vascular/fisiologiaRESUMO
Stimulation of the trigeminal nerve can elicit various cardiovascular and autonomic responses; however, the effects of anesthesia with pentobarbital sodium on these responses are unclear. Pentobarbital sodium was infused intravenously at a nominal rate and the lingual nerve was electrically stimulated at each infusion rate. Increases in systolic blood pressure (SBP) and heart rate (HR) were evoked by lingual nerve stimulation at an infusion rate between 5 and 7 mg·kg(-1)·h(-1). This response was associated with an increase in the low-frequency band of SBP variability (SBP-LF). As the infusion rate increased to 10 mg·kg(-1)·h(-1) or more, decreases in SBP and HR were observed. This response was associated with the reduction of SBP-LF. In conclusion, lingual nerve stimulation has both sympathomimetic and sympathoinhibitory effects, depending on the depth of pentobarbital anesthesia. The reaction pattern seems to be closely related to the autonomic balance produced by pentobarbital anesthesia.
Assuntos
Animais , Gatos , Masculino , Adjuvantes Anestésicos , Farmacologia , Antagonistas Adrenérgicos alfa , Farmacologia , Sistema Nervoso Autônomo , Relação Dose-Resposta a Droga , Estimulação Elétrica , Eletrocardiografia , Hemodinâmica , Hexametônio , Farmacologia , Hipnóticos e Sedativos , Farmacologia , Infusões Intravenosas , Nervo Lingual , Fisiologia , Inibição Neural , Fentolamina , Farmacologia , Nervo Trigêmeo , FisiologiaRESUMO
<p><b>OBJECTIVE</b>To re-evaluate the effects of different "cocktail therapy" to prevent from phlebitis induced by Chansu injection.</p><p><b>METHOD</b>Patients treated with Chansu injection were divided randomLy into 4 groups with 90 per group, control group, phentolaminum group, the magnesium sulfate group-phentolaminum group, and anisodamine-phentolaminum group. Patients in the control group only received the routine nursing treatment, and patients in the various experiment group received different interventions. The comparison was made in the morbidity and the starting time of occurrence of phlebitis, the severity of pain, duration of pain.</p><p><b>RESULT</b>The morbidity of phlebitis was 8%, 8%, 6%, respectively. The starting time of phlebitis occurrence was (22 +/- 4), (27 +/- 5), (28 +/- 7) h, respectively. The NRS of pain was (4.75 +/- 1.51), (3.27 +/- 1.02), (2.71 +/- 1.63), respectively. The duration time of pain was (4.25 +/- 1.36), (2.51 +/- 1.05), (2.19 +/- 1.13) d respectively. In control group, the morbidity of phlebitis, the starting time of occurrence of phlebitis, the severity of pain, duration of pain was 30%, (16 +/- 4) h, (6.34 +/- 1.21), (5.47 +/- 1.07) d, respectively. As compared with the control group, a significance difference was found between every group in three test groups and control group respectively (P<0.05).</p><p><b>CONCLUSION</b>The morbidity and the starting time of occurrence of phlebitis, the severity of pain, duration of pain was significantly reduced respectively by two different "cocktail therapy".</p>
Assuntos
Adulto , Idoso , Animais , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Anuros , Bufanolídeos , Quimioterapia Combinada , Sulfato de Magnésio , Usos Terapêuticos , Fentolamina , Usos Terapêuticos , Flebite , Tratamento Farmacológico , Alcaloides de Solanáceas , Usos TerapêuticosRESUMO
JUSTIFICATIVA E OBJETIVOS: O estudo do efeito vasomotor dos anestésicos locais (AL) é de suma importância para a análise da ocorrência de efeitos cardiotóxicos, neurotóxicos e interações medicamentosas. Com a finalidade de encontrar um fármaco mais seguro do que a bupivacaína racêmica, o presente estudo teve por objetivo a análise por imagem infravermelha digital do efeito vasomotor da intoxicação aguda da bupivacaína e da levobupivacaína via intraperitoneal em ratos. MÉTODO: Utilizaram-se 30 ratos machos da linhagem Wistar, alocados em três grupos (n = 10) e submetidos a uma injeção intraperitoneal de AL. No Grupo C (Controle), foi realizada injeção intraperitoneal de soro fisiológico 0,9 por cento 1 mL. No Grupo B (bupivacaína), injeção intraperitoneal de bupivacaína racêmica a 0,5 por cento (R50-S50), dose de 20 mg.kg-1 de peso. No Grupo L (levobupivacaína), injeção intraperitoneal de levobupivacaína a 0,5 por cento, excesso enantiomérico (S75-R25) em dose de 20 mg.kg-1 de peso. Procedeu-se à filmagem termográfica contínua desde o momento da pré-injeção até 30 minutos após a injeção. Os resultados das filmagens foram analisados em forma gráfica, verificando-se a temperatura máxima de cada rato e a temperatura média do sistema que abrigava o animal. RESULTADOS: Os resultados da análise gráfica revelaram que não houve diferença entre o Grupo L e o Grupo C, e a temperatura média permaneceu estável durante todo o experimento em ambos os grupos. No Grupo B, houve um fenômeno de aumento de temperatura após a injeção intraperitoneal de bupivacaína. CONCLUSÕES: Os resultados demonstraram que o efeito vasomotor da toxicidade aguda da levobupivacaína foi semelhante ao Grupo C com soro fisiológico, por meio de estudos macroscópicos por filmagem digital infravermelha, e que houve alterações vasomotoras (vasoconstrição) com a intoxicação por bupivacaína em relação ao Grupo C e em relação ao Grupo L.
BACKGROUND AND OBJECTIVES: The study of the vasomotor effect of local anesthetics (LA) is of paramount importance for the analysis of the occurrence of cardiotoxic and neurotoxic effects, and drug interactions. In order to find a safer drug than racemic bupivacaine, this study aimed to analyze digital infrared imaging of acute vasomotor effect of bupivacaine and levobupivacaine in rats intraperitoneally. METHOD: We used 30 male Wistar rats distributed into three groups (n = 10) and subjected to an intraperitoneal injection of LA. In Group C (control) 1 mL 0.9 percent saline was injected intraperitoneally. In Group B (bupivacaine), intraperitoneal injection of 0.5 percent of racemic bupivacaine (S50-R50), dose of 20 mg.kg-1 of body weight. In Group L (levobupivacaine), intraperitoneal injection of levobupivacaine 0.5 percent enantiomeric excess (S75-R25) in dose of 20 mg.kg-1 of body weight. The procedure was thermographicly continuously filmed from the time of pre-injection until 30 minutes after injection. The results of the recordings were analyzed in graphical form, verifying the maximum temperature of each rat and the average temperature of the system that housed the animal. RESULTS: The results of graphic analysis showed no difference between Group L and Group C, and the average temperature remained stable through-out the experiment in both groups. In Group B, there was a phenomenon of temperature increase after intraperitoneal injection of bupivacaine. CONCLUSIONS: The results demonstrated that the vasomotor effect of the acute toxicity of levobupivacaine was similar to Group C with saline, through macroscopic studies by infrared digital filmmaking, and that there were vasomotor changes (vasoconstriction), with bupivacaine intoxication in relation to both Group C and Group L.
JUSTIFICATIVA Y OBJETIVOS: El estudio del efecto vasomotor de los anestésicos locales (AL), es de suma importancia para el análisis del aparecimiento de efectos cardiotóxicos, neurotóxicos e interacciones medicamentosas. Con el fin de encontrar un fármaco más seguro que la bupivacaína racémica, el presente estudio se propuso analizar por imagen infrarroja digital, el efecto vasomotor de la intoxicación aguda de la bupivacaína y de la levobupivacaína vía intraperitoneal en ratones. MÉTODO: Fueron usados 30 ratones machos de la raza Wistar, divididos en tres grupos (n = 10) y sometidos a una inyección intraperitoneal de AL. En el Grupo C (Control), fue realizada una inyección intraperitoneal de suero fisiológico al 0,9 por ciento 1 mL. En el Grupo B (bupivacaína), una inyección intraperitoneal de bupivacaína racémica al 0,5 por ciento (R50-S50), dosis de 20 mg.kg-1 de peso. En el Grupo L (levobupivacaína), una inyección intraperitoneal de levobupivacaína al 0,5 por ciento, con exceso enantiomérico (S75-R25) en dosis de 20 mg.kg-1 de peso. Después de procedió a la filmación termográfica continua desde el momento anterior a la inyección hasta 30 minutos después de ella. Los resultados de las filmaciones se analizaron de forma gráfica, verificando la temperatura máxima de cada ratón y la temperatura promedio del sistema que abrigaba al animal. RESULTADOS: Los resultados del análisis gráfico revelaron que no hubo diferencia entre el Grupo L y el Grupo C, y que la temperatu-ra promedio se mantuvo estable durante todo el experimento en los dos grupos. En el Grupo B, se produjo un fenómeno de aumento de temperatura después de la inyección intraperitoneal de bupivacaína. CONCLUSIONES: Los resultados demostraron que el efecto vasomotor de la toxicidad aguda de la levobupivacaína fue similar al Grupo C con suero fisiológico, por medio de estudios macroscópicos por filmación digital infrarroja, y que se produjeron alteraciones vasomotoras (vasoconstricción)...
Assuntos
Animais , Ratos , Masculino , Anestésicos Locais/toxicidade , Bupivacaína/farmacologia , Bupivacaína/toxicidade , Fentolamina/farmacologia , Nicardipino/farmacologia , Termografia/métodos , Vasodilatadores/farmacologia , Sistema Vasomotor/efeitos dos fármacos , Bupivacaína/análogos & derivados , Raios Infravermelhos , Ratos Wistar , TermografiaRESUMO
JUSTIFICATIVA E OBJETIVOS: Há evidências de que a passagem de informações nociceptivas pelo corno posterior da medula espinhal (CPME) seguindo para níveis rostrais do sistema nervoso central sofre profundas influências excitatórias e inibitórias. A presente pesquisa teve como objetivo comparar os efeitos da metissergida, da fentolamina e da fentolamina associada à metissergida, administrados por via subaracnoidea, sobre as fases I, intermediária e II do teste da formalina modificado em ratos. MÉTODO: Foram utilizados 28 ratos Wistar machos, distribuídos aleatoriamente em quatro grupos (n = 7) para receber solução salina (GC), fentolamina (GF), metissergida (GM) ou fentolamina associada à metissergida (GFM) por via subaracnoidea. A dor foi induzida pela administração de formalina na região dorsal da pata posterior direita. O teste foi dividido em três fases; fase I, intermediária e fase II. A análise estatística dos resultados foi realizada utilizando o programa SPSS (Statistical Package for Social Sciences), adotando o nível de significância de 5 por cento. RESULTADOS: Na fase intermediária, o número de elevações da pata foi significativamente maior nos grupos GF, GM e GFM quando comparados com o grupo GC. CONCLUSÕES: Os resultados sugerem a existência de efeito noradrenérgico e serotoninérgico no sistema inibitório descendente da dor aguda, com a possibilidade de emprego de agonistas serotoninérgicos e α1-adrenérgicos para controle da dor aguda.
BACKGROUND AND OBJECTIVES: There is evidence that the passage of nociceptive information through the posterior horn of the spinal cord (PHSC) on its way to rostral levels of the central nervous system undergoes profound excitatory and inhibitory influences. The objective of the present study was to compare the effects of the subarachnoid administration of methysergide, phentolamine, and phentolamine associated with methysergide on phases I, intermediate, and II of the modified phormaline test in rats. METHODS: Twenty-eight male Wistar rats distributed randomly in four groups (n = 7) to received subarachnoid saline solution (GC), phentolamine (GF), methysergide (GM), or phentolamine associated with methysergide (GFM). Pain was induced by the administration of phormaline in the dorsal region of the right hind paw. The test was divided in three phases: phase I, intermediate, and phase II. Statistical analysis of the results was performed using the software SPSS (Statistical Package for Social Sciences), adopting a level of significance of 5 percent. RESULTS: In the intermediate phase the number of paw elevations was significantly higher in GF, GM, and GFM groups when compared to the GC group. CONCLUSIONS: The results suggest the existence of a noradrenergic and serotonergic effect in the inhibitory descending system of acute pain, with the possibility of using serotonergic and α1-adrenergic antagonists to control acute pain.
JUSTIFICATIVA Y OBJETIVOS: Existen evidencias de que el paso de informaciones nociceptivas por el cuerno posterior de la médula espinal (CPME), y que continúa hacia niveles rostrales del sistema nervioso central, sufre profundas influencias excitatorias e inhibitorias. La presente investigación quiso comparar los efectos de la metisergida, de la fentolamina y de la fentolamina asociada a la metisergida, administrados por vía subaracnoidea, sobre las fases I, intermedia y II del test de la formalina modificado en ratones. MÉTODO: Fueron utilizados en el experimento, 28 ratones Wistar machos, distribuidos aleatoriamente en cuatro grupos (n = 7), para recibir una solución salina (GC), fentolamina (GF), metisergida (GM) o fentolamina asociada a la metisergida ((GFM). El dolor fue inducido por la administración de formalina en la región dorsal de la pata posterior derecha. El test fue dividido en tres fases: fase I, intermedia y fase II. El análisis estadístico de los resultados fue hecho utilizando el programa SPSS (Statistical Package for Social Sciences), [Paquete Estadístico para las Ciencias Sociales], adoptando el nivel de significancia de un 5 por ciento. RESULTADOS: En la fase intermedia, el número de elevaciones de la pata fue significativamente mayor en los grupos GF, GM y GFM cuando se comparó con el grupo GC. CONCLUSIONES: Los resultados nos sugieren la existencia de un efecto noradrenérgico y serotoninérgico en el sistema inhibitorio descendiente del dolor agudo, con la posibilidad del uso de agonistas serotoninérgicos y α1-adrenérgicos para el control del dolor agudo.
Assuntos
Animais , Ratos , Masculino , Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas da Serotonina/farmacologia , Espaço Subaracnóideo/anatomia & histologia , Fentolamina/farmacologia , Metisergida , Metisergida/farmacologia , Nociceptores/efeitos dos fármacos , Nociceptores/fisiologia , Medição da Dor , Dor/fisiopatologia , Fentolamina/farmacologia , Antagonistas da Serotonina/farmacologia , Antagonistas Adrenérgicos alfa/administração & dosagem , Metisergida/administração & dosagem , Fentolamina/administração & dosagem , Ratos Wistar , Espaço Subaracnóideo , Antagonistas da Serotonina/administração & dosagemRESUMO
<p><b>OBJECTIVE</b>To re-evaluate the effects of different treatments to prevent from phlebitis induced by Chansu injection.</p><p><b>METHOD</b>Patients treated with Chansu injection were divided randomly into 4 groups with 50 per group, control group, the magnesium sulfate group, phentolaminum group, and anisodamine group. Patients in the control group only received the routine nursing treatment, and patients in the various experiment group received different interventions. The comparison was made in the morbidity and the starting time of occurrence of phlebitis, the severity of pain, duration of pain.</p><p><b>RESULT</b>The morbidity of phlebitis was 8%, 8%, 6% respectively. The starting time of phlebitis occurrence was (21 +/- 9.31) , (22.34 +/- 10.15), (20.19 +/- 11.23) h, respectively. The NRS of pain was (4. 15 +/- 1.03), (3.26 +/- 1.17), (4.32 +/- 1.36), respectively. The duration time of pain was (4.05 +/- 1.21), (3.37 +/- 1.17), (3.19 +/- 1.67) d, respectively. In control group, the morbidity of phlebitis, the starting time of occurrence of phlebitis, the severity of pain, duration of pain was 24%, (17 +/- 6.32) h, (6.58 +/- 1.29), (5.32 +/- 1.12) d, respectively. As compared with the control group, a significance difference was found between every group in three test groups and control group respectively (P<0.05).</p><p><b>CONCLUSION</b>The morbidity and the starting time of occurrence of phlebitis, the severity of pain, duration of pain was significantly reduced respectively by external appication of magnesium sulfate, anisodamine, and intravenous drip infusion of phentolaminum.</p>
Assuntos
Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Bufanolídeos , Infusões Intravenosas , Sulfato de Magnésio , Usos Terapêuticos , Morbidade , Fentolamina , Flebite , Alcaloides de Solanáceas , Usos Terapêuticos , Fatores de TempoRESUMO
In the present study, the effects of Polybia paulista venom (PPV) on renal and vascular tissues were investigated. Isolated kidneys perfused with PPV (1 and 3 ìg/mL) had increased perfusion pressure, renal vascular resistance, urinary flow, and glomerular filtration rate; and reduced sodium tubular transport. Histological evaluation demonstrated deposits of proteins in Bowman's space and tubular lumen, and focal areas of necrosis. The venom promoted a cytotoxic effect on Madin-Darby canine kidney (MDCK) cells. A significant increase in lactic dehydrogenase levels was observed in response to venom exposure. In isolated mesenteric vascular beds, pressure and vascular resistance augmented in a dose-dependent manner. PPV increased the contractility of aortic rings maintained under basal tension. This contractile response was inhibited when preparations were maintained in Ca2+-free medium. Likewise, verapamil, a voltage-gated calcium channel blocker, also inhibited the contractile response. In this study, phentolamine, a blocker of á-adrenergic receptor blocker, significantly reduced the contractile effect of PPV in the aortic ring. In conclusion, PPV produced nephrotoxicity, which suggests a direct effect on necrotic cellular death in renal tubule cells. The vascular contractile effect of PPV appears to involve calcium influx through voltage-gated calcium channels via adrenergic regulation.
Assuntos
Animais , Ratos , Aorta , Bloqueadores dos Canais de Cálcio , Rim , Venenos de Vespas , Fentolamina , Ratos Wistar , VerapamilRESUMO
Suaeda asparagoides (Miq.) has long been used as a Korean folk herbal medicine for the treatment of functional gastrointestinal disorders. However, reports on its pharmacological activity on gastrointestinal motility are scarce. The present study investigated the effects of Suaeda asparagoides water fraction of the extract (SAWF) on antral motility in vitro. Muscle strips from rat gastric antrum were set up in an organ bath in a circular orientation. SAWF (100 microg/mL) inhibited the spontaneous contraction of antral circular muscle strips. These inhibitory effects were not significantly affected by tetrodotoxin (1 microM), N omega-Nitro-L-arginine methyl ester hydrochloride (100 microM), 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (10 microM), ryanodine (10 microM) and phentolamine (10 microM). SAWF-induced inhibition was mostly restored by cyclopiazonic acid (10 microM). Furthermore, the beta-adrenergic receptor antagonist, propranolol (10 microM), abolished SAWF-induced inhibition. These results suggest that SAWF may exert its activity on gastrointestinal smooth muscle via a-adrenergic receptors and sarcoplasmic reticulum Ca2+ ATPase.
Assuntos
Animais , Ratos , Banhos , ATPases Transportadoras de Cálcio , Carbamatos , Chenopodiaceae , Contratos , Gastroenteropatias , Motilidade Gastrointestinal , Medicina Herbária , Indóis , Músculo Liso , Músculos , Compostos Organometálicos , Orientação , Oxidiazóis , Fentolamina , Propranolol , Antro Pilórico , Quinoxalinas , Rianodina , Retículo Sarcoplasmático , Tetrodotoxina , ÁguaRESUMO
Esta revisão discute o estado atual da fisiopatologia e do tratamento do infarto agudo do miocárdio relacionado ao uso de cocaína. O abuso de drogas ilícitas, em especial, da cocaína é cada vez mais frequente, com o aumento consequente da quantidade de consultas de emergências relacionadas a suas complicações, incluindo o infarto do miocárdio. Os principais mecanismos fisiopatológicos que contribuem de forma aguda ou crônica para causar o infarto relacionado ao uso de cocaína são: vasoespasmo, aterosclerose, trombogenese mediada por aumento dos níveis de fatores pró-trombóticos associada com a elevação da agregação plaquetária, aumento da demanda de oxigênio pelo miocárdio. O tratamento do infarto agudo do miocárdio relacionado ao uso de cocaína é semelhante ao do infarto na população em geral, com ácido acetilsalicílico, nitratos e oxigênio. As diferenças estão no uso de benzodiazepínicos e na contraindicação do uso de beta-bloqueadores. Existe controvérsia quanto ao uso do labetalol e da terapia trombolítica. Está sob investigação o uso de novos medicamentos como a fentolamina para reverter os efeitos de vasoconstrição e dos inibidores plaquetários para evitar a progressão do trombo.
This article aims to review current pillars of the pathophysiology and treatment of acute myocardial infarction related to cocaine use. Cocaine use has become increasingly frequent, and consequently the number of medical emergencies has increased related to its complications, including myocardial infarction. Four seems to be the pathophysiological mechanisms that contribute acutely or chronically, to cause infarction related to cocaine use: vasospasm, atherosclerosis, thrombus formation mediated by increased levels of prothrombotic factors and increased platelet aggregation, and increased demand for myocardial oxygen. The cocaine related infarction treatment is similar to infarction in general population with aspirine, nitrates and oxigen therapy. The differences are based on the use of benzodiazepines and the non indication of beta blockers, in the first case. Labetalol and trombolitic therapy use are controversial. The patophisiology knowledgement plays an important role in the introduction of new medications specific to cocaine related infarction, like phentolamine and platelets inhibitors.
Assuntos
Humanos , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/tratamento farmacológico , Transtornos Relacionados ao Uso de Cocaína/complicações , Aspirina/uso terapêutico , Fentolamina/uso terapêutico , Labetalol/efeitos adversos , Nitroglicerina/uso terapêuticoRESUMO
PURPOSE: According to various medical publications, it is believed that epinephrine should not be injected in fingers. However numerous articles show the successful use of local anesthetic with epinephrine in the digits. Epinephrine-mixed lidocaine solution enables to maintain a bloodless field for operation and provides long duration of local anesthesia when patient was wide awake. METHODS: From May 2009 to December 2009, ten patients underwent flexor tendon reconstruction with local anesthesia using epinephrine. No tourniquet was necessary. Before operation, all patients were injected with local anesthetics using 1% lidocaine 20 mL and 0.1% epinephrine 0.1 mL. RESULTS: There was no case of digital necrosis nor gangrene in the epinephrine injection. All 10 patients actively could move the finger through a full range of motion. All procedures were performed without sedation nor tourniquet and we could obtain a good vision of operative field and patients were comfortable. The patient make his or her fingers move through a full range of active motion before the skin is closed. Phentolamine was not required to reverse the vasoconstriction in any patients. CONCLUSION: The assertation that epinephrine should not be injected into the fingers is clearly no longer valid. The epinephrine injection allowed the authors to adjust flexor tendon surgery without risks associated with general anesthesia. It also enables to ensure longer anesthetic duration and bloodless operative field, and prevent post operative complications. In case of flexor tendon surgery, the use of epinephrine injection is recommended because of the advantages of local anesthesia.
Assuntos
Humanos , Anestesia , Anestesia Geral , Anestesia Local , Anestésicos Locais , Sacarose Alimentar , Epinefrina , Dedos , Gangrena , Lidocaína , Necrose , Fentolamina , Amplitude de Movimento Articular , Pele , Tendões , Torniquetes , Vasoconstrição , Visão OcularRESUMO
BACKGROUND/AIMS: Although neurotensin (NT) stimulates colon motility and the passage of intestinal contents, the associated mechanism of action remains unclear. The objective of this study was to investigate the effects of NT on colon motility using isolated rat colon. METHODS: Intraluminal pressure was measured at both the proximal and distal portions of the isolated colon. An isolated rat colon was perfused with Krebs solution via the superior mesenteric artery. After stabilization, NT was administered in concentrations of 14, 28, 138 and 276 pM. After pretreatment with phentolamine, propranolol, hexamethonium, atropine or tetrodotoxin, NT was administered at a concentration of 276 pM, and then the intraluminal pressure was monitored. RESULTS: NT significantly increased colon motility at concentrations of 14, 28, 138, and 276 in the proximal colon (25.1+/-6.5%, 175.4+/-117.0%, 240.8+/-115.1% and 252.3+/-110.6%, respectively) and in the distal colon (35.6+/-11.8%, 97.5+/-35.1%, 132.7+/-36.7% and 212.1+/-75.2%, respectively). The stimulant effect of NT was more potent in the proximal colon, in a concentration-dependent manner (P<0.05). The stimulant effect of NT was significantly inhibited by atropine at both the proximal and distal colon and by tetrodotoxin at the proximal colon, but not by tetrodotoxin at the distal colon and not by propranolol, phentolamine, or hexamethonium at both the proximal and distal colon. CONCLUSIONS: NT increased colon motility at both the proximal and distal portions of the rat colon. The effects were more prominent at the proximal portion. The results of this study suggest that the stimulant action of NT may be mediated by local cholinergic muscarinic receptors.
Assuntos
Animais , Ratos , Atropina , Vias Autônomas , Colo , Conteúdo Gastrointestinal , Hexametônio , Soluções Isotônicas , Artéria Mesentérica Superior , Neurotensina , Fentolamina , Propranolol , Receptores Muscarínicos , TetrodotoxinaRESUMO
OBJECTIVE: Peripheral nerve injury often leads to neuropathic pain, which is characterized by burning pain, allodynia, and hyperalgesia. The role of the sympathetic nervous system in neuropathic pain is a complex and controversial issue. It is generally accepted that the alpha adrenoreceptor (AR) in sympathetic nerve system plays a significant role in the maintenance of pain. Among alpha adrenoreceptor, alpha-1 receptors play a major role in the sympathetic mediated pain. The primary goal of this study is to test the hypothesis that sympathetically maintained pain involves peripheral alpha-2 receptors in human. METHODS: The study was a randomized, prospective, double-blinded, crossover study involving twenty patients. The treatments were : Yohimbine (30 mg mixed in 500 mL normal saline), and Phentolamine (1 mg/kg in 500 mL normal saline) in 500 mL normal saline at 70 mL/hr initially then titrated. The patients underwent infusions on three different appointments, at least one month apart. Thus, all patients received all 2 treatments. Pain measurement was by visual analogue scale, neuropathic pain questionnaire, and McGill pain questionnaire. RESULTS: There were significant decreases in the visual analogue scale, neuropathic score, McGill pain score of yohimnine, and phentolamine. CONCLUSION: We conclude that alpha-2 adrenoreceptor, along with alpha-2 adrenoreceptor, may be play role in sympathetically maintained pain in human.