Changes in sodium appetite evoked by lesions of the commissural nucleus of the tractus solitarius

Ablation of the area postrema/caudal nucleus of the tractus solitarius (NTS) complex increases sodium intake, but the effect of selective lesions of the caudal NTS is not known. We measured depletion-induced sodium intake in rats with electrolytic lesions of the commissural NTS that spared the area postrema. One day after the lesion, rats were depleted of sodium with furosemide (10 mg/kg body weight, sc) and then had access to water and a sodium-deficient diet for 24 h when 1.8% NaCl was offered. Water and saline intakes were measured for 2 h. Saline intake was higher in lesioned than in sham-lesioned rats (mean ± SEM: 20 ± 2 vs 11 ± 3 mL/2 h, P < 0.05, N = 6-7). Saline intake remained elevated in lesioned rats when the tests were repeated 6 and 14 days after the lesion, and water intake in these two tests was increased as well. Water intake seemed to be secondary to saline intake both in lesioned and in sham-lesioned rats. A second group of rats was offered 10% sucrose for 2 h/day before and 2, 7, and 15 days after lesion. Sucrose intake in lesioned rats was higher than in sham-lesioned rats only 7 days after lesioning. A possible explanation for the increased saline intake in rats with commissural NTS lesions could be a reduced gastrointestinal feedback inhibition. The commissural NTS is probably part of a pathway for inhibitory control of sodium intake that also involves the area postrema and the parabrachial nucleus.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FisiologiaFaculdade de Medicina do ABC Departamento de FisiologiaUNIFESP, EPM, Depto. de FisiologiaSciEL

Role of pressor mechanisms from the NTS and CVLM in control of arterial pressure

In the present study, we investigated the effects of inhibition of the caudal ventrolateral medulla (CVLM) with the GABA(A) agonist muscimol combined with the blockade of glutamatergic mechanism in the nucleus of the solitary tract (NTS) with kynurenic acid (kyn) on mean arterial pressure (MAP), heart rate (HR), and regional vascular resistances. in male Holtzman rats anesthetized intravenously with urethane/chloralose, bilateral injections of muscimol (120 pmol) into the CVLM or bilateral injections of kyn (2.7 nmol) into the NTS alone increased MAP to 186 +/- 11 and to 142 +/- 6 mmHg, respectively, vs. control: 105 +/- 4 mmHg; HR to 407 +/- 15 and to 412 +/- 18 beats per minute (bpm), respectively, vs. control: 352 +/- 12 bpm; and renal, mesenteric and hindquarter vascular resistances. However, in rats with the CVLM bilaterally blocked by muscimol, additional injections of kyn into the NTS reduced MAP to 88 +/- 5 mmHg and mesenteric and hindquarter vascular resistances below control baseline levels. Moreover, in rats with the glutamatergic mechanisms of the NTS blocked by bilateral injections of kyn, additional injections of muscimol into the CVLM also reduced MAP to 92 +/- 2 mmHg and mesenteric and hindquarter vascular resistances below control baseline levels. Simultaneous blockade of NTS and CVLM did not modify the increase in HR but also abolished the increase in renal vascular resistance produced by each treatment alone. the results suggest that important pressor mechanisms arise from the NTS and CVLM to control vascular resistance and arterial pressure under the conditions of the present study.Universidade Federal de São Paulo, Dept Physiol, EPM, São Paulo, BrazilUNESP, Fac Odontol, Dept Physiol & Pathol, Araraquara, BrazilABC, Fac Med, Dept Physiol, Santo Andre, BrazilUniversidade Federal de São Paulo, Dept Physiol, EPM, São Paulo, BrazilWeb of Scienc

Vehicle influence on potassium replacement effectiveness in hypokalemic rats

INTRODUCTION: Patients who undergo cardiac surgery are commonly treated with diuretic therapy for the management of volume overload. The concern of hypokalemia important in the adult population submitted to cardiac surgery has been described. Intravenous potassium (K+) replacement dilution is only recommended with sodium chloride 0.9% solution (SF0.9%), likely due to the putative effects of glucose solution 5% (SG5%) on insulin secretion, which influence K+ replacement quality. However, it is not yet experimentally proved the influence of SF0.9% and SG5% on K+ replacement quality. Objectives: To evaluate the effects of different vehicles of K+ replacement on blood K+ levels in furosemide hypokalemic rats. METHODS: Male Wistar rats divided into four groups: K+SF, K+SG, SF and SG. Jugular vein cannulation for K+ replacement and femoral vein cannulation for blood analysis. Furosemide (50mg/kg) to induce hypokalemia. We prepared the following solutions: vehicle 1.6mL (SF0.9% or SG5%) + 0.4 mL de K+ (19.1%) and for control groups only vehicle 2 mL. Furosemide (50 mg/kg) was used to induce hypokalaemia, it was analyzed potassium plasmatic levels 24 hours before furosemide injection, 24 hours after furosemide injection and 30 minutes after post-replacement. RESULTS: There was no significative difference in blood K+ levels before furosemide administration, after hypokalemic induction and after K+ replacement among all groups. Only SF+K presented blood Na+ levels increaseafter K+ replacement (P<0.05). CONCLUSION: K+ replacement in different vehicles did not affect blood K+ levels in ratsINTRODUÇÃO: Pacientes após cirurgia cardíaca são comumente tratados com diuréticos para controle de volume plasmático. A preocupação de distúrbios hipocalêmicos em adultos antes, durante ou após a cirurgia já foi ressaltada anteriormente, visto o risco de arritmias cardíacas. Clinicamente, a diluição da solução de potássio (K+) para administração por via intravenosa, em situações que requerem a sua reposição é realizada utilizando-se soro fisiológico (SF) ao invés de soro glicosado 5% (SG5%), possivelmente em vista de poder ocorrer estimulação da secreção de insulina, que interferiria sobre a qualidade da reposição de K+. Porém, não está comprovado experimentalmente se o SF e SG5% poderiam realmente interferir na qualidade da reposição de potássio em ratos com hipocalemia. OBJETIVO: Analisar a influência da reposição de K+ diluído em diferentes veículos sobre as concentrações plasmáticas de K+([K+]p) em ratos submetidos a hipocalemia induzida por furosemida. MÉTODOS: Ratos Wistar adultos foram divididos em quatro grupos: K++SF, K++SG, SF e SG. Foi realizada a canulação da veia jugular para reposição e da veia femoral para coleta de sangue. O diurético furosemida na dose de 50mg/kg foi usado para induzir hipocalemia, foi analisado nível plasmático de potássio 24 h antes da injeção de furosemida, 24 h pós-indução e 30 minutos pós-reposição. RESULTADOS: Os níveis da [K+] pós-injeção de furosemida sofreram redução, comparado aos valores basais (pré-furosemida) em todos os grupos. Entretanto, os níveis [K+] retornaram aos valores basais tanto nos grupos que receberam K++SF ou K++SG, o que não foi observado nos grupos que receberam apenas SF e SG. Quanto ao Na+ plasmático, somente o grupo K+SF apresentou aumento após reposição. CONCLUSÃO: A reposição de K+ diluído tanto em SF quanto SG parece não afetar a qualidade da reposição de K+ plasmático em ratosUniversidade Federal de São Paulo (UNIFESP) Departamento de MedicinaFaculdade de Medicina do ABC Departamento de FisiologiaUNIFESP, Depto. de MedicinaSciEL

La Libertad : ¿cómo vamos en educación?

Reúne información estadística relevante de la situación actual de la educación de la región La Libertad, ha sido elaborado para servir como una guía informativa amigable para aquellos actores de la región que puedan influir positivamente en su realidad educativa. Entre 2004 y 2013, la tasa media de crecimiento anual del gasto público educativo por alumno fue de 13% en inicial, 15% en primaria y 9% en secundaria, aunque está por debajo del gasto nacional en todos los años, a excepción de los años 2007 y 2008 para el nivel inicial. El porcentaje de escuelas con acceso a Internet de La Libertad en primaria pasó de 4.3% en 2005 a 33.7% en 2014, superando ese año al nacional (27.9%), mientras que en secundaria, pasó de 12.3% a 52.7%, parecido al valor nacional (52.0%). Sin embargo, hay amplia variabilidad de acceso en las provincias; así, en primaria algunas se encuentran en el cuarto quintil y otras en el primer quintil; más aún, en secundaria algunas provincias se encuentran en el quinto quintil y otras en el primero. En el ámbito distrital las diferencias son aún mayores. Entre 2004 y 2013, las tasas netas de asistencia en la región son iguales al promedio nacional, a excepción del 2005 en inicial y del 2004, 2006 y 2007 en secundaria en que las superan. En 2005 la brecha desfavorable a la región llega a -11 puntos en inicial, mientras que la mayor brecha en secundaria es de -11.7 el 2004. Para los otros años no existen diferencias entre ámbitos porque no son estadísticamente significativas. En el período 2005-2014 La Libertad ha tenido más alumnos por docentes en inicial y primaria, en la mayoría de años, respecto al promedio nacional, mientras que en secundaria ha sido igual entre ámbitos. En el ámbito regional aparecen divergencias entre provincias y niveles. Así, Gran Chimú tiene los menores valores en todos los niveles (14 alumnos por docente en inicial, 10 en primaria y 8 en secundaria), Pataz tiene el mayor valor en inicial (23) y Sánchez Carrión en primaria (21) y en secundaria (15). En el ámbito distrital, las diferencias son todavía más marcadas. La Libertad tiene tasas parecidas de desaprobación y retiro, en primaria y secundaria, que el promedio nacional, pero el porcentaje de atraso es ligeramente mayor en la región que en el Perú. El porcentaje de desaprobados en primaria fluctúa bastante, entre 1.6% en Chepén hasta 8.2% en Bolívar, en tanto que en secundaria oscila entre 4.4% en Ascope y 12.3% en Virú. El atraso escolar es mayor en secundaria que en primaria, especialmente en la provincia de Pataz (29.8%). También, el atraso escolar es superior al promedio de los dos niveles educacionales a la vez en 46 distritos, en tanto que en el 2013 el mayor porcentaje de retirados en primaria se encuentra en Gran Chimú (4.0%) y en secundaria en Julcán (7.7%)

Effects of the administration of a catalase inhibitor into the fourth cerebral ventricle on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke

OBJECTIVE: Previous studies have demonstrated a relationship between brain oxidative stress and cardiovascular regulation. We evaluated the effects of central catalase inhibition on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke. METHODS: Male Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SH) (16 weeks old) were implanted with a stainless steel guide cannula leading into the fourth cerebral ventricle (4th V). The femoral artery and vein were cannulated for arterial pressure and heart rate measurement and drug infusion, respectively. The rats were exposed to sidestream cigarette smoke for 180 minutes/day, 5 days/week for 3 weeks (CO: 100-300 ppm). The baroreflex was tested using a pressor dose of phenylephrine (8 μg/kg, bolus) and a depressor dose of sodium nitroprusside (50 μg/kg, bolus). Cardiovascular responses were evaluated before and 5, 15, 30 and 60 minutes after injection of a catalase inhibitor (3-amino-1,2,4-triazole, 0.001 g/100 μL) into the 4th V. RESULTS: Vehicle administration into the 4th V did not affect the cardiovascular response, whereas administration of the central catalase inhibitor increased the basal HR and attenuated the bradycardic peak (p<0.05) to a greater extent in WKY rats exposed to sidestream cigarette smoke than in WKY rats exposed to fresh air. However, in spontaneously hypertensive rats, the effect of the catalase inhibitor treatment was stronger in the fresh air condition (p<0.05). CONCLUSION: Administration of a catalase inhibitor into the 4th V combined with exposure to sidestream cigarette smoke has a stronger effect in WKY rats than in SH rats.Foundation of Support to Research of Sao Paulo State (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESP)Universidade Estadual Paulista Faculdade de Ciências e TecnologiaFaculdade de Medicina do ABC Departamento de Morfologia e FisiologiaUniversidade Federal de São Paulo (UNIFESP)UNIFESP, EPM10/17769-7SciEL

COMPARATIVE EVALUATION OF SKIN SUTURE IN RATS WITH POLYGLYCAPRONE 25 AND NYLON

ABSTRACT Currently, the market offers a wide variety of suture threads, made of materials with different structural and chemical properties. Among many other characteristics, they vary in origin, absorption or degradation, and structure. From this variety, the clinical doubt arises as to which material provides the patient with the best healing quality. Objective: This study aims to comparatively evaluate two different types of suture threads-Monocryl® (polyglycaprone 25) and Ethilon® (nylon)-regarding their ability to aid in tissue regeneration by a histological and immunohistochemical analysis of the skin of rats sutured with the aforementioned materials. Methods: This basic experimental study used 12 adult Wistar rats, randomly divided into three groups with four animals each and subjected to four longitudinal incisions under anesthesia. Each group corresponded to a postsurgical evaluation date (one, seven, and 14 days). Results: At 14 postoperative days, the studied groups had no histological difference. However, the use of nylon thread showed greater evidence of earlier fibrotic union. Conclusion: This study found no histological difference in healing 14 days after surgery among the techniques and the types of suture threads. Level of Evidence II, Therapeutic Studies

Morphological and functional changes in urinary bladder of multiparous female rats submitted to resistance exercise

Objective: investigate whether resistance exercise can induce morphological and functional alterations in urinary bladder (UB) in multiparous rats. Methods: we used 40 adults female Wistar rats of which 20 were nulliparous and 20 were multiparous submitted to different volumes of moderate resistance exercise (one, three or ten weeks). Animals were submitted to the functional evaluation of UB. At the end of the protocol, the UB was removed, weighed and stained with hematoxylin and eosin for structural evaluation, and picrosirius red for collagen fibers. Results: we observed that multiparity promoted increase in body mass, reduction in UB layers, decrease in volume densities of collagen fibers I and III. However, 10-weeks of training was able to reverse the negative effects of multiparity. Conclusion: the intervention of physical exercise in 10 weeks times seems to cause greater benefit in UB of multiparous animals by preventing morphofunctional changes that trigger lower urinary tract symptoms, such as urinary loss

Role of nucleus of solitary tract on the cardiovascular responses produced by bilateral common carotid arteries occlusion

O presente estudo teve como objetivo determinar o efeito da lesao eletrolitica do NTS comissural nas respostas cardiovasculares promovidas pela oclusao bilateral das arterias carotidas comuns em ratos nao anestesiados. No animais com lesao eletroiltica aguda (l dia) do NTS comissurai houve um potenciacao tanto do lº quanto do 2º componente da resposta pressora a oclusao das carotidas. A lesao eletrolitica do NTS comissurai aboliu as resposta cardiovasculares do quimiorreflexo induzido pelo cianeto de potassio e nao alterou as respostas do barorreflexo induzido por doses pressoras de fenilefrina entretanto, promoveu reducao da taquicardia reflexa induzida por dose depressoras de nitroprussiato de sodio. Estes resultados sugerem que o quimiorreceptores parecem nao estar envolvidos na resposta pressora potencial a oclusao das carotidas, que foi observada nos animais com lesao do NTS comissural. Uma vez que a lesao do NTS comissural potenciou a resposta pressora a oclusao das carotidas, tambem nos propusemos a analisar o envolvimento do componente simpatico e da vasopressina no aparecimento desta resposta. Para tanto, realizamos o bloqueio farmacologico sequencial, utilizando prazosin + metoprolol + antagonista de vasopressina nos animais com lesao do NTS comissurai ou com lesao ficticia e observamos que, em ambos os grupos de animais, houve reducao do lº e do 2º componente da resposta pressora a oclusao das carotidas, quando foi realizado o bloqueio simpatico com prazosin e metoprolol, porem nao se observou reducao adicional de ambos os componentes apos a administracao do antagonista de vasopressina, nos dois grupos de animais. No entanto, quando invertemos a ordem do bloqueio farmacologico, administrando primeiramente o antagonista de vasopressina, depois prazosin e por ultimo o metoprolol, observamos que nos animais com lesao do NTS comissural houve reducao tanto do lº quanto do 2º componente da resposta pressora a oclusao das carotidas apos o tratamento com antagonista de vasopressina e apos o tratamento com prazosin e metoprolol, houve reducao adicional do lº componente, mas nao do 2º componente. Nos animais com lesao ficticia, nao houve alteracao da resposta pressora a oclusao das carotidas apos a administracao do antagonista de vassopressina e somente apos a realizacao do bloqueio simpatico houve reducao desta resposta. Estes resultados sugerem que nos animais com lesao ficticia ou do NTS comissural, a resposta pressora...(au)BV UNIFESP: Teses e dissertaçõe

Study of the importance of the nucleus of the solitary tract on arterial pressure control in spontaneously hypertensive rats

Nos ratos espontaneamente hipertensos (SHR), a pressao arterial comeca a se elevar 2 a 3 semanas apos o nascimento e um plato de hipertensao e atingido com 12 a 14 semanas de idade. Varios estudos mostraram que a pressao arterial elevada dos SHR parece estar associada a atividade simpatica aumentada. A destruicao quimica do simpatico com 6hidroxidopamina interfere significantemente no desenvolvimento da hipertensao dos SHR. Diferentes estudos tem sugerido o envolvimento dos neuronios catecolaminergicos centrais nos mecanismos de hipertensao. A sensibilidade dos barorreceptores no controle reflexo da frequencia cardiaca parece estar diminuida nos SHR, porem existem controversias em relacao a sensibilidade do barorreflexo quando analisado pelo controle da atividade simpatica. Existem evidencias de que a atividade dos aferentes quimiorreceptores esta aumentada nos SHR, o que levou a sugerir o possivel envolvimento dos quimiorreceptores nos mecanismos de hipertensao. O nucleo do tracto solitario comissural (NTScom) contem os neuronios catecolaminergicos do grupo A2. Trabalhos demonstraram que a lesao eletrolitica do NTScom abole as respostas reflexas dos quimiorreceptores carotideos induzidas pelo cianeto de potassio. Outras evidencias mostraram que ratos Wistar com lesao do NTScom e desnervacao aodica permanecem normotensos, enquanto ratos com lesao ficticia do NTScom e desnervacao aortica tornam-se hipertensos, sugerindo uma possivel participacao dos quimiorreceptores nos mecanismos de hipertensao neurogenica. Portanto, considerando-se as evidencias de que: a) o NTScom contem os neuronios catecolaminergicos do grupo A2 e b) a lesao eletrolitica do NTScom abole o quimiorreflexo induzido pelo cianeto de potassio e sabendo-se que nos SHR, os aferentes quimiorreceptores apresentam atividade...(au)BV UNIFESP: Teses e dissertaçõe