Linalool-rich rosewood oil induces vago-vagal bradycardic and depressor reflex in rats.

Cardiovascular effects of the linalool-rich essential oil of Aniba rosaeodora (here named as EOAR) in normotensive rats were investigated. In anesthetized rats, intravenous (i.v.) injection of EOAR induced dose-dependent biphasic hypotension and bradycardia. Emphasis was given to the first phase (phase 1) of the cardiovascular effects, which is rapid (onset time of 1-3 s) and not observed in animals submitted to bilateral vagotomy or selective blockade of neural conduction of vagal C-fibre afferents by perineural treatment with capsaicin. Phase 1 was also absent when EOAR was directly injected into the left ventricle injection, but it was unaltered by i.v. pretreatment with capsazepine, ondansetron or HC030031. In conscious rats, EOAR induced rapid and monophasic hypotensive and bradycardiac (phase 1) effects that were abolished by i.v. methylatropine. In endothelium-intact aortic rings, EOAR fully relaxed phenylephrine-induced contractions in a concentration-dependent manner. The present findings reveal that phase 1 of the bradycardiac and depressor responses induced by EOAR has a vago-vagal reflex origin resulting from the vagal pulmonary afferents stimulation. Such phenomenon appears not to involve the recruitment of C-fibre afferents expressing 5HT3 receptors or the two chemosensory ion channels TRPV1 and TRPA1 . Phase 2 hypotensive response appears resulting from a direct vasodilatory action.

Vasorelaxant effects of 1-nitro-2-phenylethene in rat isolated aortic rings.

Previously, we showed that nitro-2-phenylethane is a vasorelaxant constituent of the essential oil of Aniba canelilla. Here, we investigated the mechanisms underlying the vascular effects of 1-nitro-2-phenylethene (NPe), a structural analog of 1-nitro-2-phenylethane obtained synthetically, in rat isolated thoracic aortic preparations. At 0.1-100 µg/mL, NPe similarly relaxed endothelium-intact or endothelium-denuded aortic preparations pre-contracted with 60mM KCl or with phenylephrine (PHE, 1 µM). Vasorelaxant effects of NPe against PHE-induced contractions remained unaffected following blockade of potassium channels by TEA, and inhibition of either nitric oxide synthase by l-NAME, cyclooxygenase by indomethacin or guanylate cyclase by ODQ. In preparations maintained under Ca(2+)-free conditions, NPe significantly reduced the contractions induced (i) by PHE, but not those evoked by caffeine, (ii) by CaCl2 in either PHE (in the presence of 1 µM verapamil)- or KCl-stimulated preparations, (iii) by extracellular Ca(2+) restoration in thapsigargin-treated aortic preparations, and (iv) by the activator of protein kinase C phorbol-12,13-dibutyrate or the inhibitor of protein tyrosine phosphatase sodium orthovanadate. It is concluded that NPe induced an endothelium-independent vasorelaxation with potency greater than its structural analog 1-nitro-2-phenylethane. Such action appears to occur intracellularly probably through inhibition of contractile events that are clearly independent of Ca(2+) influx from the extracellular milieu.

Analgesic efficacy of the association of cryotherapy and transcutaneous electrical nerve stimulation / Eficácia analgésica da associação da crioterapia e da estimulação elétrica nervosa transcutânea

ABSTRACT BACKGROUND AND OBJECTIVES: Cryotherapy and transcutaneous electrical nerve stimulation are physiotherapeutic resources widely used for the treatment of pain, due to their analgesic actions proved by scientific evidence. The concomitant use of these two therapeutic modalities in clinical practice is becoming more and more recurrent, justified by the assumption of boosting the analgesic effect. However, some physiotherapists disagree with this practice and believe that the simultaneous use of cryotherapy and transcutaneous electrical nerve stimulation nullifies its effects. The objective of this study was to carry out a bibliographic review of studies on the effects of the simultaneous use of cryotherapy and transcutaneous electrical nerve stimulation in pain treatments. CONTENTS: We selected articles published between 2006-2018 in the databases Scielo, LILACS, Medline and Pubmed. The selection was based on the crossing of the keywords: transcutaneous electrical nerve stimulation, cryotherapy and analgesia. The final sample consisted of 6 articles. CONCLUSION: The results of the analysis of the selected articles showed that, as already scientifically proved, the effects of cryotherapy and transcutaneous electrical nerve stimulation alone have their analgesic efficacy. However, most of the studies did not demonstrate a significant improvement in pain with the associated use of transcutaneous electrical nerve stimulation and cryotherapy compared to the isolated use of these physiotherapeutic resources, reinforcing the need for further research to elucidate the issue.

RESUMO JUSTIFICATIVA E OBJETIVOS: Crioterapia e estimulação elétrica nervosa transcutânea são recursos fisioterapêuticos amplamente utilizados para o tratamento da dor, devido a suas ações analgésicas comprovadas por evidências científicas. Torna-se cada vez mais recorrente o uso concomitante dessas duas modalidades terapêuticas na prática clínica, justificando-se com o pressuposto de potencialização do efeito analgésico. No entanto, alguns fisioterapeutas discordam dessa prática e acreditam que o uso simultâneo da crioterapia com a estimulação elétrica nervosa transcutânea leva à anulação dos seus efeitos. O objetivo deste estudo foi realizar uma revisão bibliográfica de estudos sobre os efeitos do uso simultâneo da crioterapia e da estimulação elétrica nervosa transcutânea nos tratamentos para dor. CONTEÚDO: Foram selecionados artigos publicados entre os anos 2006-2018 nas seguintes bibliotecas e bases de dados: Scielo, LILACS, Medline e Pubmed. A seleção foi baseada no cruzamento dos descritores: estimulação elétrica nervosa transcutânea, crioterapia e analgesia. A amostra final foi composta por 6 artigos. CONCLUSÃO: O resultado da análise dos artigos selecionados mostrou que, como já comprovado cientificamente, os efeitos da crioterapia e da estimulação elétrica nervosa transcutânea isoladamente têm sua eficácia analgésica. Entretanto, a maioria dos estudos não demonstrou melhora significativa da dor com o uso associado da crioterapia com estimulação elétrica nervosa transcutânea comparado ao uso isolado dos recursos fisioterapêuticos, reforçando a necessidade de mais pesquisas que elucidem a questão.

Efeito do diidrocloreto de 2, 2’-azobis (2-metilpropionamidina) sobre músculo liso de traquéia de rato / The effects of 2, 2-azobis (2-amidinopropane) dihydrochloride on tracheal smooth muscle

The effects of 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AAPH), an inducer agent of free radicals (peroxyl radical) formation, on the rat tracheal smooth muscle. The experiments were performed on tracheal ring preparations maintained in aerated modified Tyrode solution, in pH 7,4 at 37 °C. The force developed by the tracheal smooth muscle was measured by the isometric force transducer connected to a computerized system. On contractions induced by acetylcholine (10 M), AAPH presented a biphasic effect: contraction potentiation at low concentration on intact and denuded epithelium preparations (CE50 = 0,8776  0,415 mM and CE50 = 0,3338  0,343 mM, respectively); and contraction inhibition at high concentration on intact and denuded epithelium preparations (CE50 = 81,55 62 4,284 mM and CE50 = 57,7786  8,607 mM, respectively). On electromechanic coupling, AAPH inhibited contractions induced by KCl (60 mM) on intact and denuded epithelium preparations (CE50 = 57,4037  4,652 mM and CE50 = 32,9650  2,652 mM, respectively). In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. Comparing the present data with those available in literature for H2O2, we can suggest that these observed effects are not specific for AAPH, but they are derived from the free radicals induced by AAPH.

Efeito do diidrocloreto de 2, 2-azobis (2-metilpropionamidina) sobre músculo liso de traquéia de rato / The effects of 2, 2-azobis (2-amidinopropane) dihydrochloride on tracheal smooth muscle

The effects of 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AAPH), an inducer agent of free radicals (peroxyl radical) formation, on the rat tracheal smooth muscle. The experiments were performed on tracheal ring preparations maintained in aerated modified Tyrode solution, in pH 7,4 at 37 °C. The force developed by the tracheal smooth muscle was measured by the isometric force transducer connected to a computerized system. On contractions induced by acetylcholine (10 M), AAPH presented a biphasic effect: contraction potentiation at low concentration on intact and denuded epithelium preparations (CE50 = 0,8776  0,415 mM and CE50 = 0,3338  0,343 mM, respectively); and contraction inhibition at high concentration on intact and denuded epithelium preparations (CE50 = 81,55 62 4,284 mM and CE50 = 57,7786  8,607 mM, respectively). On electromechanic coupling, AAPH inhibited contractions induced by KCl (60 mM) on intact and denuded epithelium preparations (CE50 = 57,4037  4,652 mM and CE50 = 32,9650  2,652 mM, respectively). In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. Comparing the present data with those available in literature for H2O2, we can suggest that these observed effects are not specific for AAPH, but they are derived from the free radicals induced by AAPH.(AU)