Role of the medial septal area on the cardiovascular, fluid and electrolytic responses to angiotensin II and cholinergic activation into the subfornical organ in rats

In the present study we investigated the effect of electrolytic lesion of the medial septal area (MSA) on the pressor and dipsogenic response to cholinergic activation and angiotensin II (ANGII) injection into the subfornical organ (SFO) in rats. In addition the effect of MSA lesion on the natriuresis, kaliuresis and diuresis after cholinergic activation of the SFO was also investigated. Sham- and MSA-lesioned rats with a stainless steel cannula implanted into the SFO was used. The injection of ANGII (12 ng) into the SFO in sham rats produced pressor (24 ± 2 mmHg) and dipsogenic (9.6 ± 1.1 ml/h) responses. MSA lesion, both acute (2-6 days) and chronic (15-19 days), reduced the pressor (14 ± 2 mmHg) and dipsogenic (2.7 ± 1 ml/h) responses to ANGII into SFO. The injection of the cholinergic agonist carbachol (2 nmol) into the SFO in sham rats produced pressor (48 ± 4 mmHg), dipsogenic (10 ± 1.2 ml/h), natriuretic (457 ± 58 μEq/2 h) and kaliuretic (249 ± 16 μEq/2 h) responses. Acute, but not chronic MSA lesion reduced the pressor (27 ± 3 mmHg), natriuretic (198 ± 55 μEq/2 h) and kaliuretic (128 ± 16 μEq/2 h) responses to carbachol into SFO. No change in the dipsogenic response to carbachol into the SFO was observed in MSA-lesioned rats. Antidiuresis after carbachol was observed only in MSA-lesioned rats. The present results show that the MSA plays a role on the pressor, natriuretic and kaliuretic responses to cholinergic activation of the SFO in rats and on the pressor and dipsogenic responses to ANGII into the same area. In addition, they provide circumstancial evidence for separate circuits subserving the dipsogenic response to central cholinergic and angiotensinergic activation. A facilited diuresis after MSA lesion is also suggested.

Estudo comparativo entre cinco diferentes tratamentos sobre as alterações clínicas e laboratoriais do rato diabético induzido pela aloxana

OBJETIVOS: Este estudo visa a analisar os efeitos, a longo prazo, de cinco diferentes tratamentos sobre o controle metabólico de ratos diabéticos aloxânicos. MÉTODOS: Foram analisados 7 grupos experimentais, com 50 ratos cada um, sendo: GN o grupo controle normal; GD o grupo controle diabético, sem tratamento; GI, GA e GIA os grupos tratados, respectivamente, com insulina, acarbose e associação insulina + acarbose; GTIL o grupo tratado com transplante de ilhotas de Langerhans; e o GTPD o grupo tratado com transplante pancreatoduodenal heterotópico. Parâmetros clínicos (peso, ingestão hídrica, ingestão alimentar e diurese) e laboratoriais (glicemia, glicose urinária e insulina plasmática) foram avaliados em todos os animais, no início do experimento, e após 1, 3, 6, 9 e 12 meses de seguimento. RESULTADOS: À exceção do GN, mortalidade foi observada em todos os grupos experimentais no seguimento de 12 meses (GD= 50%; GI= 20%; GA= 26%; GIA= 18%; GTIL= 4%; GTPD= 20%). em GD, GI, GA e GIA os óbitos ocorreram por distúrbios metabólicos ou hidroeletrolíticos e/ou pneumonia, diarréia e caquexia; em GTIL e GTPD todos os óbitos ocorreram por falhas técnicas no pós-operatório até 72h. Animais dos grupos GI, GA e GIA tiveram melhora significativa (p < 0,05) de todos os parâmetros clínicos e laboratoriais observados em ratos diabéticos, sem diferença de efetividade entre os tratamentos. Porém, os resultados observados nestes grupos, biologicamente não foram comparáveis aos observados em GTIL e GTPD, onde observou-se correção completa, aos níveis normais, de todas as variáveis analisadas (p<0,01). CONCLUSÕES: Os tratamentos convencionais com insulina, acarbose e insulina + acarbose melhoraram o estado diabético grave dos ratos tratados, contudo, a eficácia dos tratamentos foi significativamente inferior à oferecida pelo GTIL e GTPD.

Variações diurnas da temperatura corporal, proteínas plasmáticas e eritrograma de cabras não prenhes

Hemogram values may have variations caused by intrinsic or extrinsic factors, which can take healthy animals to present values outside of the normal reference ranges and it is important to the veterinarian to know these variation factors for a correct results interpretation. The influence of the period of the day is among them. The objective of this study was to test the hypothesis that there are hematological parameters variations, such as erythrogram and plasmatic proteins during the day. The study was carried out with 10 non-pregnant adult goats in Araçatuba/SP/Brazil. The blood sampling and physical exam occurred at three moments between 07:00 and 08:00 a.m. (M1), 12:30 and 01:30 p.m. (M2), 5:00 and 6:00 p.m. (M3). We noted differences in the values of packed cell volume (PCV), hemoglobin, and rectal temperature through the moments, with reduction of PCV and hemoglobin were related to increase in rectal and air temperature, leading to water intake increase and, consequently, decreasing blood concentration. These variations could lead to an error of interpretation of the results due to values below the reference ranges.

Role of alfa2-adrenoceptors in the lateral parabrachial nucleus in the control of body fluid homeostasis

Central α2-adrenoceptors and the pontine lateral parabrachial nucleus (LPBN) are involved in the control of sodium and water intake. Bilateral injections of moxonidine (α2-adrenergic/imidazoline receptor agonist) or noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a combined treatment of furosemide plus captopril. Injection of moxonidine into the LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion, urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium and water balance, which suggests that moxonidine injected into the LPBN deactivates mechanisms that restrain body fluid volume expansion. Pretreatment with specific α2-adrenoceptor antagonists injected into the LPBN abolishes the behavioral and renal effects of moxonidine or noradrenaline injected into the same area, suggesting that these effects depend on activation of LPBN α2-adrenoceptors. In fluid-depleted rats, the palatability of sodium is reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated with moxonidine injected into the LPBN, the NaCl palatability remains high, even after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and renal responses produced by activation of α2-adrenoceptors in the LPBN are probably a consequence of reduction of oxytocin secretion and blockade of inhibitory signals that affect sodium palatability. In this review, a model is proposed to show how activation of α2-adrenoceptors in the LPBN may affect palatability and, consequently, ingestion of sodium as well as renal sodium excretion.

Proposta de gestão ambiental para o Instituto Federal de Educação, Ciência e Tecnologia do Piauí, campus Teresina Central

Pós-graduação em Geografia - IGCE

Fibra, metabolismo ácido-básico e balanço de macroelementos em gatos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Consumo de hidroxiprolina e amido e supersaturação urinária para oxalato de cálcio em gatos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fluoride Intake from Meals Served in Daycare Centres in Municipalities with Different Fluoride Concentrations in the Water Supply

Purpose: The aim of this study was (1) to determine the fluoride content in the meals served to children aged up to 36 months in daycare centres of two municipalities with different levels of fluoride in the water supply, (2) to calculate the mean fluoride ingested daily by the children when consuming those meals and (3) to analyse the contribution of this consumption to the development of dental fluorosisMaterials and Methods: Samples of the meals served to the children were collected during a whole week. The fluoride content of the samples of solid foods and milk was analysed using an ion-specific electrode combined with reference electrode after diffusion facilitated by hexamethyldisiloxane Samples of beverages were buffered with an equal volume of total ionic strength adjustment buffer and analysed using a combined electrode. The results were compared using the Mann Whitney testResults: Mean fluoride contents of the meals were of 0.204 +/- 0 179 and 0.322 +/- 0.242 mu g F/mL (P < 0.05), respectively, in the municipalities with low and adequate fluoride content. Daily fluoride intake in the former was 0.013 +/- 0.003 mg/kg body weight/day and in the latter was 0.012 +/- 0 001 mg/kg body weight/day (P > 0 05)Conclusions: The children were not exposed to dental fluorosis in the daycare centres However, the risk cannot be ignored, considering the meals and the use of fluoridated dentifrices at home may also contribute to fluoride intake.

Lateral hypothalamus lesions influences water and salt intake, and sodium and urine excretion, and arterial blood pressure induced by L-NAME and FK 409 injections into median preoptic nucleus in conscious rats

Male Holtzman rats weighting 200-250 g were anesthetized with zoletil 50 mg/Kg (tiletamine chloridrate 125,0 mg and zolazepan chloridrate 125,0 mg) into quadriceps muscle and submitted an electrolytic lesion of the lateral hypothalamus (LH) and a stainless steel cannula was implanted into their median preoptic nucleus (MnPO). We investigated the effects of the injection into the (MnPO) of FK 409 (20 mug/0.5 mul), a nitric oxide (NO) donor, and N-W-nitro-L-arginine methyl ester (L-NAME) 40 mug/0.5 mul, a nitric oxide synthase inhibitor (NOSI), on the water and sodium appetite and the natriuretic, diuretic and cardiovascular effects induced by injection of L-NAME and FK 409 injected into MnPO in rats with LH lesions. Controls were injected with a similar volume of 0.15 M NaCl. L-NAME injected into MnPO produced an increase in water and sodium intake and in sodium and urine excretion and increase de mean arterial pressure (MAP). FK 409 injected into MnPO did not produce any change in the hydro electrolytic and cardiovascular parameters in LH-sham and lesioned rats. FK 409 injected before L-NAME attenuated its effects. These data show that electrolytic lesion of the LH reduces fluid and sodium intake as well as sodium and urine excretion, and the pressor effect induced by L-NAME. LH involvement with NO of the MnPO excitatory and inhibitory mechanisms related to water and sodium intake, sodium excretion and cardiovascular control is suggested. (C) 2004 Elsevier B.V. All rights reserved.

Cafeteria diet intake for fourteen weeks can cause obesity and insulin resistance in Wistar rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Increase of gastric area and weight gain in rats submitted to the ingestion of gasified water

OBJETIVO: em virtude do aumento progressivo da utilização de bebidas gaseificadas e do ganho de peso na população brasileira, e sabendo-se que os refrigerantes têm no gás carbônico um fator em comum, planejou-se um estudo experimental em ratos para investigar os efeitos da água gaseificada na ingestão hídrica e alimentar, ganho de peso, área gástrica, glicemia, hematócrito e hemoglobina. MÉTODOS: Foram constituídos 4 grupos de 12 ratos acompanhados por 36 dias. Ao Grupo-1 foi oferecido 35 g/dia de ração ad libitum e 20 ml de água não gaseificada em 4 períodos diários, ao Grupo-2 foi oferecido 35 g/dia de ração ad libitum e 20 ml de água gaseificada em 4 períodos diários, ao Grupo-3 foi oferecido 10 g/dia de ração ad libitum e 20 ml de água não gaseificada em 4 períodos diários e ao Grupo-4 foi oferecido 10 g/dia de ração ad libitum e 20 ml de água gaseificada em 4 períodos diários. RESULTADOS: Os resultados identificaram que os animais que foram submetidos ao tratamento com água gaseificada (Grupo-2 e Grupo-4), apresentaram um maior volume de ingestão hídrica e aumento significativo da área gástrica (p<0,001), no Grupo-2 a ingestão alimentar assim como o ganho de peso foi significativo (p<0,01), os dados de glicemia, hematócrito e hemoglobina não tiveram alterações significativas entre os grupos estudados. CONCLUSÃO: Nas condições em que foi realizado este experimento, concluímos que a água gaseificada favoreceu a ingestão hídrica e alimentar, o ganho de peso e o aumento da área gástrica.

Armadillo meat intake was not associated with leprosy in a case control study, Curitiba (Brazil)

Leprosy's progression and its maintained endemic status, despite the availability of effective treatments, are not fully understood and recent studies have highlighted the possibility of involved Mycobacterium leprae ambient reservoirs. Wild armadillos can carry leprosy and, because their meat is eaten by humans, development of the disease among armadillo meat consumers has been investigated. This study evaluated the frequency of armadillo meat intake among leprosy patients as well as age and gender matched controls with other skin diseases from a dermatological unit. Armadillo meat consumption among both groups was adjusted by demographic and socioeconomic covariates based on a conditional multiple logistic regression model. One hundred twenty-one cases and 242 controls were evaluated; they differed in socioeconomic variables such as family income, hometown population and access to treated water. The multivariate analysis did not show an association between the intake of armadillo meat and leprosy (odds ratio = 1.07; CI 95% 0.56-2.04), even when only cases with no known contacts were analyzed. We conclude that leprosy is not associated with the intake of armadillo meat in these patients.

Mutagenic and carcinogenic potential of a textile azo dye processing plant effluent that impacts a drinking water source

Recently a textile azo dye processing plant effluent was identified as one of the sources of mutagenic activity detected in the Cristais River, a drinking water source in Brazil [G.A. Umbuzeiro, D.A. Roubicek, C.M. Rech, M.I.Z. Sato, L.D. Claxton, Investigating the sources of the mutagenic activity found in a river using the Salmonella assay and different water extraction procedures, Chemosphere 54 (2004) 1589-1597]. Besides presenting high mutagenic activity in the Salmonella/microsome assay, the mutagenic nitro-aminoazobenzenes dyes CI Disperse Blue 373, Cl Disperse Violet 93, and CI Disperse Orange 37 [G.A. Umbuzeiro, H.S. Freeman, S.H. Warren, D.P Oliveira, Y. Terao, T. Watanabe, L.D. Claxton, the contribution of azo dyes in the mutagenic activity of the Cristais river, Chemosphere 60 (2005) 55-64] as well as benzidine, a known carcinogenic compound [T.M. Mazzo, A.A. Saczk, G.A. Umbuzeiro, M.V.B. Zanoni, Analysis of aromatic amines in surface waters receiving wastewater from textile industry by liquid chromatographic with eletrochemical detection, Anal. Lett., in press] were found in this effluent. After similar to 6 km from the discharge of this effluent, a drinking water treatment plant treats and distributes the water to a population of approximate 60,000. As shown previously, the mutagens in the DWTP intake water are not completely removed by the treatment. The water used for human consumption presented mutagenic activity related to nitro-aromatics and aromatic amines compounds probably derived from the cited textile processing plant effluent discharge [G.A. Umbuzeiro, D.A. Roubicek, C.M. Rech, M.I.Z.. Sato, L.D. Claxton, Investigating the sources of the mutagenic activity found in a river using the Salmonella assay and different water extraction procedures, Chemosphere 54 (2004) 1589-1597; G.A. Umbuzeiro, H.S. Freeman, S.H. Warren, D.P. Oliveira, Y. Terao, T. Watanabe, L.D. Claxton, the contribution of azo dyes in the multagenic activity of the Cristais river, Chemosphere 60 (2005) 55-64]. Therefore, it is important to evaluate the possible risks involved in the human consumption of this contaminated water. With that objective, one sample of the cited industrial effluent was tested for carcinogenicity in the aberrant crypt foci medium-term assay in colon of Wistar rats. The rats received the effluent in natura through drinking water at concentrations of 0.1%, 1%, and 10%. The effluent mutagenicity was also confirmed in the Salmonella/microsome assay with the strains TA98 and YG1041. There was an increased number of preneoplastic lesions in the colon of rats exposed to concentrations of 1% and 10% of the effluent, and a positive response for both Salmonella strains tested. These results indicate that the discharge of the effluent should be avoided in waters used for human consumption and show the sensitivity of the ACF crypt foci assay as an important tool to evaluate the carcinogenic potential of environmental complex mixtures. (c) 2006 Elsevier B.V. All rights reserved.