Ca2+-dependent K+ channels are targets for bradykinin B-1 receptor ligands and for lipopolysaccharide in the rat aorta

Although rat aorta smooth muscle cells in culture constitutively express bradykinin B, receptors, the normotensive rat aorta does not respond to the bradykinin B, receptor agonist des-Arg(9)-bradykinin, whereas vessels from the spontaneously hypertensive rat (SFIR) respond to bradykinin B, receptor agonists with cell membrane hyperpolarization and relaxation. Bacterial lipopolysaccharide also is inactive on the normotensive rat but hyperpolarizes the SFIR aorta. To determine whether this could be due to the increased intracellular Ca2+ concentration ([Ca2+](i)) in the SHR, we raised [Ca2+](i) in normotensive rats by treatment with thapsigargin. fit the thapsigargin-treated aorta, both lipopolysaccharide and des-Arg(9)-bradykinin induced hyperpolarization, which was reversed by the Ca2+-dependent K+ channel inhibitor iberiotoxin and by the bradykinin B, receptor antagonists Lys-[Leu(8)]-des-Arg(9)-bradykinin and [Leu(8)]-des-Arg9-bradykinin. Thus the bradykinin B-1 receptor, as well as lipopolysaccharide, needs activated Ca2+-dependent K+ channels for functional expression. the two bradykinin B-1 receptor inhibitors, however, have effects oil Ca2+-dependent K+ channels which are not mediated by bradykinin B, receptors. (c) 2005 Elsevier B.V. All rights reserved.Universidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023062 São Paulo, BrazilWeb of Scienc

Lys-[Leu(8),des-Arg(9)]-bradykinin blocks lipopolysaccharide-induced SHR aorta hyperpolarization by inhibition of Ca++- and ATP-dependent K+ channels

The mediators involved in the hyperpolarizing effects of lipopolysaccharide and of the bradykinin B, receptor agonist des-Arg(9)-bradykinin on the rat aorta were investigated by comparing the responses of aortic rings of spontaneously hypertensive and normotensive Wistar rats. Endothelized rings from hypertensive rats were hyperpolarized by des-Arg(9)-bradykinin and lipopolysaccharide, whereas deendothelized rings responded to lipopolysaccharide but not to des-Arg(9)-bradykinin. in endothelized preparations, the responses to des-Arg(9)-bradykinin were inhibited by N-nitro-L-arginine and iberiotoxin. De-endothelized ring responses to lipopolysaccharide were inhibited by iberiotoxin, glibenclamide and B, antagonist Lys-[Leu(8),des-Arg(9)]-bradykinin. This antagonist also inhibited hyperpolarization by des-Arg(9)-bradykinin and by the a(2)-adrenoceptor agonist, brimonidine. Our results indicate that Ca2+-sensitive K+ channels are the final mediators of the responses to des-Arg(9)-bradykinin, whereas both Ca2+- and ATP-sensitive K+ channels mediate the responses to lipopolysaccharide. the inhibitory effects of Lys-[Leu(8),des-Arg(9)]-bradykinin is due to a direct action on Ca2+- and ATP-sensitive potassium channels. (C) 2004 Elsevier B.V All rights reserved.Universidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023062 São Paulo, BrazilWeb of Scienc

Characterization of alpha(2)-adrenoceptors in smooth muscles of the spontaneously hypertensive rat aorta

Previous works have shown that the alpha(2)-adrenoceptor agonist UK 14,304 induced the relaxation and hyperpolarization of the rat aorta, mediated by alpha(2)-adrenoceptors present in the smooth muscles, through small-conductance, ATP-sensitive K+ channels. We now report that in spontaneously hypertensive rat (SHR) aortic rings, UK 14,304 induced concentration-dependent hyperpolarizing responses, which were inhibited by yohimbine, an alpha2-adrenoceptor inhibitor, and by glibenclamide, a specific inhibitor of small-conductance, ATP-sensitive K+ channels. the responses were also partially inhibited by iberiotoxin and by apamin. Treatment with N-omega-nitro-L-arginine (L-NNA) did not affect the response to UK 14,304. These results indicate that alpha(2)-adrenoceptors are present in SHR aortic smooth muscle cell membranes, but differ from those of normotensive animals regarding the K+ channels involved in their responses. Moreover, the resting membrane potential (RMP) was significantly more negative in SHR than in normotensive rats. This relative hyperpolarized state is probably due to Cat(2+)-dependent K+ channels being constitutively open in SHR, since the addition of iberiotoxin caused a significant depolarization of the aortic smooth muscle membranes in this strain. (C) 2003 Elsevier Science Inc. All rights reserved.Universidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023032 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023032 São Paulo, SP, BrazilWeb of Scienc

Aspectos fisiopatológicos e assistenciais de enfermagem na reabilitação da pessoa com lesão medular Aspectos fisiopatológicos y asistenciales de enfermería en la rehabilitación de la persona con lesión medular Physiopathological aspects and nursing care on rehabilitation of patient with spinal cord injury

O traumatismo raquimedular é uma agressão à medula espinhal que pode ocasionar danos neurológicos, tais como alteração das funções motora, sensitiva e autônoma. Este artigo tem como propósito relatar detalhadamente as principais complicações clínicas resultantes desse tipo de lesão, e apresentar as intervenções assistenciais de enfermagem que possam auxiliar na promoção do bem estar e na melhoria da qualidade de vida dos pacientes, seja em caráter de acometimento já instalado ou profilático.<br>El traumatismo de la médula espinal puede llevar a daños neurológicos, incluso a la alteración de las funciones motora, sensorial y autonómica. En este trabajo nos proponemos descubrir detalladamente las más importantes complicaciones clínicas resultantes de ese tipo de lesión, y enseñar las intervenciones asistenciales de enfermería que puedan ayudar en la promoción del bienestar y en la mejora de la calidad de vida de los pacientes, sea en carácter de lesión ya instalada o en carácter profiláctico.<br>Spinal cord injury can cause neurological damage such as alterations in the motor, sensitive and autonomic function. In this paper, details of clinical complications such as PVT, infection, respiratory insufficiency, pressure ulcers, autossomic disreflection, orthostatic hypotension, sphincteral-vesical and intestinal disfunctions, are related. And will also present prophylactic and therapeutic nursing care interventions designed for the well-being and improvement in life quality for patients

Investigação das falhas técnicas verificadas em próteses auditivas de usuários de um programa público de saúde auditiva

Objetivo analisar as falhas técnicas em próteses auditivas de um grupo de usuários do Programa de Saúde Auditiva de uma Universidade em Curitiba. Métodos analisou-se o relatório técnico de 104 próteses de usuários que compareceram ao serviço para a consulta de acompanhamento. Resultados o relatório apontou para defeitos em: 21% receptor; 15% caixa; 12% suspensão; 9% microfone; 2% amplificador. Com relação à causa provável do defeito: 58% desgaste em função do tempo de uso; 25% umidade; 23% mau uso. Quanto ao valor dos consertos: mínimo de R$44,00 para revisão e limpeza (36$900,00 para substituição de peças (9,6%); 21% da amostra teve o orçamento realizado entre R$100,00 e R$500,00; 37% dos aparelhos foram substituídos. Conclusão Os defeitos detectados deveram-se a problemas de manuseio entre os usuários recentes, e desgaste entre os usuários mais antigos