Tyrosine hydroxylase immunoreactivity as indicator of sympathetic activity: simultaneous evaluation in different tissues of hypertensive rats

Burgi K, Cavalleri MT, Alves AS, Britto LRG, Antunes VR, Michelini LC. Tyrosine hydroxylase immunoreactivity as indicator of sympathetic activity: simultaneous evaluation in different tissues of hypertensive rats. Am J Physiol Regul Integr Comp Physiol 300: R264-R271, 2011. First published December 9, 2010; doi: 10.1152/ajpregu.00687.2009.-Vasomotor control by the sympathetic nervous system presents substantial heterogeneity within different tissues, providing appropriate homeostatic responses to maintain basal/stimulated cardiovascular function both at normal and pathological conditions. The availability of a reproducible technique for simultaneous measurement of sympathetic drive to different tissues is of great interest to uncover regional patterns of sympathetic nerve activity (SNA). We propose the association of tyrosine hydroxylase immunoreactivity (THir) with image analysis to quantify norepinephrine (NE) content within nerve terminals in arteries/arterioles as a good index for regional sympathetic outflow. THir was measured in fixed arterioles of kidney, heart, and skeletal muscle of WistarKyoto rats (WKY) and spontaneously hypertensive rats (SHR) (123 +/- 2 and 181 +/- 4 mmHg, 300 +/- 8 and 352 +/- 8 beats/min, respectively). There was a differential THir distribution in both groups: higher THir was observed in the kidney and skeletal muscle (similar to 3-4-fold vs. heart arterioles) of WKY; in SHR, THir was increased in the kidney and heart (2.4- and 5.3-fold vs. WKY, respectively) with no change in the skeletal muscle arterioles. Observed THir changes were confirmed by either: 1) determination of NE content (high-performance liquid chromatography) in fresh tissues (SHR vs. WKY): +34% and +17% in kidney and heart, respectively, with no change in the skeletal muscle; 2) direct recording of renal (RSNA) and lumbar SNA (LSNA) in anesthetized rats, showing increased RSNA but unchanged LSNA in SHR vs. WKY. THir in skeletal muscle arterioles, NE content in femoral artery, and LSNA were simultaneously reduced by exercise training in the WKY group. Results indicate that THir is a valuable technique to simultaneously evaluate regional patterns of sympathetic activity.

Ventrolateral medulla mechanisms involved in cardiorespiratory responses to central chemoreceptor activation in rats

A rise in arterial PCO(2) stimulates breathing and sympathetic activity to the heart and blood vessels. In the present study, we investigated the involvement of the retrotrapezoid nucleus (RTN) and glutamatergic mechanisms in the Botzinger/C1 region (Botz/C1) in these responses. Splanchnic sympathetic nerve discharge (sSND) and phrenic nerve discharge (PND) were recorded in urethane-anesthetized, sino-aortic-denervated, vagotomized, and artificially ventilated rats subjected to hypercapnia (end-expiratory CO(2) from 5% to 10%). Phrenic activity was absent at end-expiratory CO(2) of 4%, and strongly increased when end-expiratory CO(2) reached 10%. Hypercapnia also increased sSND by 103 +/- 7%. Bilateral injections of the GABA-A agonist muscimol (2 mM) into the RTN eliminated the PND and blunted the sSND activation (Delta = +56 +8%) elicited by hypercapnia. Injections of NMDA receptor antagonist AP-5 (100 mM), non-NMDA receptor antagonist 6,7-dinitro-quinoxaline-2,3-dione (DNQX; 100 mM) or metabotropic glutamate receptor antagonist (+/-)-alpha-methyl-4-carboxyphenylglycine (MCPG; 100 mM) bilaterally into the Botz/C1 reduced PND (Delta = +43 +/- 7%, +52 +/- 6% or +56 +/- 11%, respectively). MCPG also reduced sSND (Delta = +41 +/- 7%), whereas AP-5 and DNQX had no effect. In conclusion, the increase in sSND caused by hypercapnia depends on increased activity of the RTN and on metabotropic receptors in the Botz/C1, whereas PND depends on increased RTN activity and both ionotropic and metabotropic receptors in the Botz/C1.

UPR induces transient burst of apoptosis in islets of early lactating rats through reduced AKT phosphorylation via ATF4/CHOP stimulation of TRB3 expression

Bromati CR, Lellis-Santos C, Yamanaka TS, Nogueira TC, Leonelli M, Caperuto LC, Gorjao R, Leite AR, Anhe GF, Bordin S. UPR induces transient burst of apoptosis in islets of early lactating rats through reduced AKT phosphorylation via ATF4/CHOP stimulation of TRB3 expression. Am J Physiol Regul Integr Comp Physiol 300: R92-R100, 2011. First published November 10, 2010; doi:10.1152/ajpregu.00169.2010.-Endocrine pancreas from pregnant rats undergoes several adaptations that comprise increase in beta-cell number, mass and insulin secretion, and reduction of apoptosis. Lactogens are the main hormones that account for these changes. Maternal pancreas, however, returns to a nonpregnant state just after the delivery. The precise mechanism by which this reversal occurs is not settled but, in spite of high lactogen levels, a transient increase in apoptosis was already reported as early as the 3rd day of lactation (L3). Our results revealed that maternal islets displayed a transient increase in DNA fragmentation at L3, in parallel with decreased RAC-alpha serine/threonine-protein kinase (AKT) phosphorylation (pAKT), a known prosurvival kinase. Wortmannin completely abolished the prosurvival action of prolactin (PRL) in cultured islets. Decreased pAKT in L3-islets correlated with increased Tribble 3 (TRB3) expression, a pseudokinase inhibitor of AKT. PERK and eIF2 alpha phosphorylation transiently increased in islets from rats at the first day after delivery, followed by an increase in immunoglobulin heavy chain-binding protein (BiP), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP) in islets from L3 rats. Chromatin immunoprecipitation (ChIP) and Re-ChIP experiments further confirmed increased binding of the heterodimer ATF4/CHOP to the TRB3 promoter in L3 islets. Treatment with PBA, a chemical chaperone that inhibits UPR, restored pAKT levels and inhibited the increase in apoptosis found in L3. Moreover, PBA reduced CHOP and TRB3 levels in beta-cell from L3 rats. Altogether, our study collects compelling evidence that UPR underlies the physiological and transient increase in beta-cell apoptosis after delivery. The UPR is likely to counteract prosurvival actions of PRL by reducing pAKT through ATF4/CHOP-induced TRB3 expression.

Cloning and characterization of a zebrafish homologue of human AQP1: a bifunctional water and gas channel

Chen LM, Zhao J, Musa-Aziz R, Pelletier MF, Drummond IA, Boron WF. Cloning and characterization of a zebrafish homologue of human AQP1: a bifunctional water and gas channel. Am J Physiol Regul Integr Comp Physiol 299: R1163-R1174, 2010. First published August 25, 2010; doi:10.1152/ajpregu.00319.2010.-The mammalian aquaporins AQP1, AQP4, and AQP5 have been shown to function not only as water channels but also as gas channels. Zebrafish have two genes encoding an AQP1 homologue, aqp1a and aqp1b. In the present study, we cloned the cDNA that encodes the zebrafish protein Aqp1a from the 72-h postfertilization (hpf) embryo of Danio rerio, as well as from the swim bladder of the adult. The deduced amino-acid sequence of aqp1a consists of 260 amino acids and is 59% identical to human AQP1. By analyzing the genomic DNA sequence, we identified four exons in the aqp1a gene. By in situ hybridization, aqp1a is expressed transiently in the developing vasculature and in erythrocytes from 16 to 48 h of development. Later, at 72 hpf, aqp1a is expressed in dermal ionocytes and in the swim bladder. Western blot analysis of adult tissues reveals that Aqp1a is most highly expressed in the eye and swim bladder. Xenopus oocytes expressing aqp1a have a channel-dependent (*) osmotic water permeability (P(f)*) that is indistinguishable from that of human AQP1. On the basis of the magnitude of the transient change in surface pH (Delta pHS) that were recorded as the oocytes were exposed to either CO(2) or NH(3), we conclude that zebrafish Aqp1a is permeable to both CO(2) and NH(3). The ratio (Delta pHS*)CO2/P(f)* is about half that of human AQP1, and the ratio (Delta pHS*)NH3/P(f)* is about one-quarter that of human AQP1. Thus, compared with human AQP1, zebrafish Aqp1a has about twice the selectivity for CO(2) over NH(3).

Anesthetic Activation of Central Respiratory Chemoreceptor Neurons Involves Inhibition of a THIK-1-Like Background K(+) Current

At surgical depths of anesthesia, inhalational anesthetics cause a loss of motor response to painful stimuli (i.e., immobilization) that is characterized by profound inhibition of spinal motor circuits. Yet, although clearly depressed, the respiratory motor system continues to provide adequate ventilation under these same conditions. Here, we show that isoflurane causes robust activation of CO(2)/pH-sensitive, Phox2b-expressing neurons located in the retrotrapezoid nucleus (RTN) of the rodent brainstem, in vitro and in vivo. In brainstem slices from Phox2b-eGFP mice, the firing of pH-sensitive RTN neurons was strongly increased by isoflurane, independent of prevailing pH conditions. At least two ionic mechanisms contributed to anesthetic activation of RTN neurons: activation of an Na(+)-dependent cationic current and inhibition of a background K(+) current. Single-cell reverse transcription-PCR analysis of dissociated green fluorescent protein-labeled RTN neurons revealed expression of THIK-1 (TWIK-related halothane-inhibited K(+) channel, K(2P)13.1), a channel that shares key properties with the native RTN current (i.e., suppression by inhalational anesthetics, weak rectification, inhibition by extracellular Na(+), and pH-insensitivity). Isoflurane also increased firing rate of RTN chemosensitive neurons in urethane-anesthetized rats, again independent of CO(2) levels. In these animals, isoflurane transiently enhanced activity of the respiratory system, an effect that was most prominent at low levels of respiratory drive and mediated primarily by an increase in respiratory frequency. These data indicate that inhalational anesthetics cause activation of RTN neurons, which serve an important integrative role in respiratory control; the increased drive provided by enhanced RTN neuronal activity may contribute, in part, to maintaining respiratory motor activity under immobilizing anesthetic conditions.

Exercise changes regional vascular control by commissural NTS in spontaneously hypertensive rats

Ogihara CA, Schoorlemmer GHM, Levada AC, Pithon-Curi TC, Curi R, Lopes OU, Colombari E, Sato MA. Exercise changes regional vascular control by commissural NTS in spontaneously hypertensive rats. Am J Physiol Regul Integr Comp Physiol 299: R291-R297, 2010. First published April 21, 2010; doi: 10.1152/ajpregu.00055.2009.-Inhibition of the commissural nucleus of the solitary tract (commNTS) induces a fall in sympathetic nerve activity and blood pressure in spontaneously hypertensive rats (SHR), which suggests that this subnucleus of the NTS is a source of sympathoexcitation. Exercise training reduces sympathetic activity and arterial pressure. The purpose of the present study was to investigate whether the swimming exercise can modify the regional vascular responses evoked by inhibition of the commNTS neurons in SHR and normotensive Wistar-Kyoto (WKY) rats. Exercise consisted of swimming, 1 h/day, 5 days/wk for 6 wks, with a load of 2% of the body weight. The day after the last exercise session, the rats were anesthetized with intravenous alpha-chloralose, tracheostomized, and artificially ventilated. The femoral artery was cannulated for mean arterial pressure (MAP) and heart rate recordings, and Doppler flow probes were placed around the lower abdominal aorta and superior mesenteric artery. Microinjection of 50 mM GABA into the commNTS caused similar reductions in MAP in swimming and sedentary SHR (-25 +/- 6 and -30 +/- 5 mmHg, respectively), but hindlimb vascular conductance increased twofold in exercised vs. sedentary SHR (54 +/- 8 vs. 24 +/- 5%). GABA into the commNTS caused smaller reductions in MAP in swimming and sedentary WKY rats (-20 +/- 4 and -16 +/- 2 mmHg). Hindlimb conductance increased fourfold in exercised vs. sedentary WKY rats (75 +/- 2% vs. 19 +/- 3%). Therefore, our data suggest that the swimming exercise induced changes in commNTS neurons, as shown by a greater enhancement of hindlimb vasodilatation in WKY vs. SHR rats in response to GABAergic inhibition of these neurons.

Antineoplasic activity of Copaifera multijuga oil and fractions against ascitic and solid Ehrlich tumor

The aim of this study was to investigate the effect of chronic treatment with C. multijuga oil on Ehrlich tumor evolution. C multijuga was fractionated in a KOH impregnated silica gel column chromatography to give three distinct fractions, i.e., hexanic, chloroformic, and methanolic, mainly composed by hydrocarbon sesquiterpenes, oxygenated sesquiterpenes and acidic diterpenes, respectively. Results demonstrated that the C multijuga oil, the hexanic, and chloroformic fractions did not develop toxic effects. The oil, hexanic and chloroformic fractions (doses varying between 100 and 200 mg/kg) showed antineoplasic properties against Ehrlich ascitic tumor (EAT) and solid tumor during 10 consecutive days of treatment inhibiting ascitic tumor cell number, reverting medulla and blood cell counts to values similar to control group, and inhibiting the increase on several inflammatory mediators (total protein, PGE(2), nitric oxide, and TNF) on ascitic fluid. The treatment also inhibited the increase in paw volume on tumor-inoculated mice. In conclusion, C. multijugo as well as its fractions demonstrated antineoplasic effect even after oral administration confirming its use by traditional medicine. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

The Estrous Cycle Modulates Small Leucine-Rich Proteoglycans Expression in Mouse Uterine Tissues

In the pregnant mouse uterus, small leucine-rich proteoglycans (SLRPs) are drastically remodeled within a few hours after fertilization, suggesting that ovarian hormone levels modulate their synthesis and degradation. In this study, we followed by immunoperoxidase approach, the presence of four members of the SLRP family (decorin, lumican, biglycan, and fibromodulin) in the uterine tissues along the estrous cycle of the mouse. All molecules except fibromodulin, which predominates in the myometrium, showed a striking modulation in their distribution in the endometrial stroma, following the rise in the level of estrogen. Moreover, notable differences in the distribution of SLRPs were observed between superficial and deep stroma, as well as between the internal and external layers of the myometrium. Only biglycan and fibromodulin were expressed in the luminal and glandular epithelia. All four SLRPs were found in cytoplasmic granules of mononucleated cells. The pattern of distribution of the immunoreaction for these molecules in the uterine tissues was found to be estrous cycle-stage dependent, suggesting that these molecules undergo ovarian hormonal control and probably participate in the preparation of the uterus for decidualization and embryo implantation. In addition, this and previous results from our laboratory suggest the existence of two subpopulations of endometrial fibroblasts that may be related to the centrifugal development of the decidua. Anat Rec, 292:138-153, 2009. (c) 2008 Wiley-Liss, Inc.

The Dynamics of The Firm : In Search for a General Model

This paper describe a model from system theory that can be used as a base for better understanding of different situations in the firms evolution. This change model is derived from the theory of organic systems and divides the evolution of the system into higher complexity of the system structure in three distinctive phases. These phases are a formative phase, a normative phase and an integrative phase. After a summary of different types of models of the dynamics of the firm the paper makes a theoretical presentation of the model and how this model is adaptable for better understanding of the need for change in strategic orientation, organization form and leadership style over time.

Actitudes hacia el catal��n : un estudio socioling����stico de principiantes del catal��n en Barcelona

This study focuses on the Catalan language of Catalonia, a region located in the east of Spain. There are many immigrants living in this region who decide to learn the Catalan language in hope of finding a job or to integrate in the Catalan society. The main aim of this study was to discover the types of language attitudes the beginners of Catalan show towards this language (general, instrumental and integrative attitudes). Language attitudes are of importance because it can indicate the ���health��� of a minority language, such as is usually considered Catalan. The method applied was direct, where the informants had to answer a written questionnaire. The results of the study show positive attitudes towards the Catalan language and its general use in Catalonia. The main conclusions of the study were that the informants showed positive and slightly more instrumental attitudes towards Catalan, indicating that the main motive of learning the language was more of practical use than integrative motives.

Actitudes hacia el castellano y el catal��n : Un estudio socioling����stico entre veintea��eros y sus padres en el ��mbito

This study focuses on the attitudes toward Catalan and Spanish, the two main languages spoken in Barcelona, on the East coast of Spain, in Southwestern Europe. The aim of this study was to compare those attitudes between two generations of informants. The informants of one generation were born 1984-93 and were thus in their twenties at the time of the investigation, in 2013. The aforementioned generation was labelled with the name "Children", whereas their parents were labelled with the name "Parents". The method applied was direct, where the informants had to answer an online survey, and the number of informants that were studied was 15 for each generation, or 30 in total. The conclusion of the study, derived from the results to the aforementioned survey, is that the generation of the Children have a more positive attitude toward Catalan and more negative toward Spanish than the generation of the Parents.

Actitudes hacia la lengua n��huatl : Un estudio socioling����stico con j��venes de la Ciudad deM��xico.

Nahuatl is one of the indigenous languages in Mexico that is at risk of falling out of use. The research in the last years have showed that this occurs due to the low amount of Nahuatl speakers and the social stigma and discrimination towards the indigenous peoples, among other factors.The studies of language attitudes are relevant when making attempts to revitalize a language. As Mexico City authorities have considered to implement a revitalization project, we wanted to approach the real situation of Nahuatl in that city. Our purpose was to measure the attitudes of young people towards this language. By using a direct method ���a questionnaire- we asked two groups of students if they agreed or disagreed with some items about Nahuatl and its speakers. One group had contact with Nahuatl speakers and but not the other one. We compared the results and they showed that the students who have contact with Nahuatl have more positive attitudes than those who don���t have any contact with it. This study also revealed that the reason why the first group showed positive attitudes was solidarity with the Nahuatl speakers. However, the both groups considered that speaking or learning Nahuatl cannot contribute to raise their status in the Mexican society.

Conflito e negocia����o : estudo de caso em uma ind��stria de transforma����o do Rio Grande do Sul

Esta pesquisa trata do tema conflito e negocia����o. O objetivo geral foi mapear e analisar situa����es de conflito e o seu processo de negocia����o em uma ind��stria de transforma����o do Rio Grande do Sul. Utilizou-se tanto o m��todo do estudo de caso para uma pesquisa explorat��ria e de car��ter descritivo, como a pesquisa-a����o. Os sujeitos da pesquisa foram 21 alunos de um curso de ���Negocia����o��� em abril de 2002, o superintendente e a chefia do setor Talentos Humanos da empresa. Para a coleta dos dados foram utilizadas observa����es participantes, an��lise de documentos, filmagens e entrevistas semi-estruturadas. A coleta de dados ocorreu entre abril de 2002 e abril de 2003. Investigou-se e foi realizada interven����o na din��mica dos conflitos no ��mbito interno da empresa, diagnosticando os conflitos e analisando os resultados obtidos por meio do m��todo de negocia����o desenvolvido na Universidade de Harvard. Os resultados demonstraram que a iniciativa para a escolha do modelo negocial integrativo ou competitivo partia da chefia; os subordinados apenas reagiam seguindo o modelo proposto, ou seja, de forma integrativa ou competitiva. Em se tratando de negocia����es entre colegas e com fornecedores, o modelo integrativo era adotado por iniciativa dos sujeitos, inclusive virando jogos competitivos em integrativos. Tamb��m foi constatado que a utiliza����o do processo integrativo para solu����o de conflitos/problemas no ��mbito organizacional �� uma forma apropriada para melhores resultados e mais satisfa����o para todos os envolvidos, humanizando e trazendo a ��tica para as rela����es. A participa����o de uma terceira pessoa na reformula����o da forma de negociar trouxe desdobramentos significativos para os sujeitos, atribuindo-se a isso a postura imparcial e a credibilidade alcan��ada. Finalmente, as conex��es entre o pensamento de Habermas desenvolvido na Teoria da A����o Comunicativa e o m��todo de negocia����o de Harvard ficaram evidentes.

Pr��ticas e resultados de apre��amento nas empresas brasileiras - 1�� Parte

Este relat��rio refere-se �� primeira parte de uma pesquisa financiada pelo N��cleo de Pesquisas e Publica����es (GV-PESQUISA) da EAESP-FGV e apoiada pelo Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq). Trata-se dos determinantes do desempenho de novos produtos, um tema ainda pouco estudado no Brasil, a partir de um modelo integrativo das concep����es de INGENBLEEK, DREBUYNE, FRAMBACH & VERHALLEN (2004) e HENARD & SZYMANSKI (2001). Formou-se uma amostra de 109 gerentes de produto e diretores de marketing de empresas estrangeiras atuando no Brasil. O Desempenho do Novo Produto apresentou uma rela����o significativa e positiva com Orienta����o para o Mercado e Processo de Desenvolvimento de Novos Produtos. O Desempenho de Mercado do Novo Produto mostrou uma rela����o significativa e positiva com Caracter��sticas dos Processos da Empresa, Vantagem Relativa do Novo Produto e Caracter��sticas do Mercado. O Desempenho Financeiro do Novo Produto apareceu com uma rela����o significativa com Caracter��sticas dos Processos da Empresa (positiva), Caracter��sticas Estrat��gicas da Empresa (positiva) e Incerteza da Demanda (negativa). Ao final, s��o apontadas e discutidas, de modo preliminar, as limita����es, conclus��es e implica����es da pesquisa.

O impacto de reestrutura����o e privatiza����o na gest��o integrada do setor de energia el��trica: an��lise do setor a partir da abordagem de redes

The Brazilian energetic sector is passing through deep transformations. The restructure is mainly characterized by the passage from a vertical and centrally coordinated system, in hands of the State, to a more horizontal one, with characteristics of a network, in which organizations, such as the National Agency of Electric Energy (ANEEL), the new regulator entity, the Wholesaler Market of Electric Energy (MAE), the National Operator of Electric System (ONS), Eletrobr��s and the National Bank of Economic and Social Development (BNDES) are designated as the principals integrators of the system. The objective of the present work was to analyze the influence of the privatization and restructuring processes in the integration of the Brazilian system of electric energy. The analysis was based on the instruments offered by the network approach. The results of the research show that the Brazilian sector of electric energy cannot be considered as a highly integrated network. In this new horizontal configuration, the social actors are affirming its roles, functions and objectives, while the key-organization like ANEEL, ONS, MAE, Eletrobr��s, and BNDES are being structured to strengthen its integrative role.