Toxic effects of nickel exposure on heart and liver of rats

The role of air pollution as a health risk factor is of special interest. Numerous toxic pollutants, such as nickel, are being released to the environment as a result of combustion of fossil fuels, crude oil, and coal. Nickel in the atmosphere can be combined with other environmental pollutants, producing various nickel compounds, which have varying animal toxicity. A rat biossay validated for the identification of toxic effects of nickel revealed increased serum activities of total lactate dehydrogenase (LDH) and alanine transaminase (ALT) in rats that received intratracheal injection of Ni2+ in .09% saline solution of NiCl2. The total LDH activity was also increased in the heart, and the isoenzyme pattern showed the LDH1/LDH2 ratio elevated to greater than 1. We conclude that intratracheal administration of nickel induced cardiac and hepatic damage. The development of cardiac and hepatic damage and of increased enzymes' activities was only demonstrated when nickel had accumulated in these tissues, indicating that nickel depot is essential to its toxicity. Intratracheal administration of NiCl2 induced changes in LDH and ALT activities.

Anatomical features of the urethra and urinary bladder catheterization in female mice and rats. An essential translational tool

PURPOSE: To present fundamental anatomical aspects and technical skills necessary to urethra and urinary bladder catheterization in female mice and rats. METHODS: Urethral and bladder catheterization has been widely utilized for carcinogenesis and cancer research and still remains very useful in several applications: from toxicological purposes as well as inflammatory and infectious conditions to functional aspects as bladder dynamics and vesicoureteral reflux, among many others. RESULTS: Animal models are in the center of translational research and those involving rodents are the most important nowadays due to several advantages including human reproducibility, easy handling and low cost. CONCLUSIONS: Although technical and anatomical pearls for rodent urethral and bladder access are presented as tackles to the advancement of lower urinary tract preclinical investigation in a broaden sight, restriction to female animals hampers the male microenvironment, demanding future advances.

Kinetics of chronic inflammation in Nile tilapia fed n-3 and n-6 essential fatty acids

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

Muscle response to the association of statin and physical exercise in rats

Physical exercise and statins, which are recommended for the treatment of dyslipidemia, are independently associated to the occurrence of muscle injury. The objective is analyze the effect of aerobic exercise associated to the use of simvastatin on the morphology of the gastrocnemius muscle. Thirty Wistar rats were divided into six groups, two of which received a standard diet (1 sedentary and 1 exercised) and four (1 sedentary with medication, 1 sedentary without medication, 1 exercised with medication, 1 exercised without medication) received a hypercholesterolemic diet (standard diet with the addition of cholesterol and coconut oil). Simvastatin (20 mg/Kg) was administered five days a week for eight weeks, together with aerobic training on a treadmill (9.75 m/min) for 60 minutes a day. The gastrocnemius muscle was removed, sliced, stained with Hematoxylin-Eosin and submitted to a histochemical reaction to determine mitochondrial activity. The data were analyzed using a paired t-test, analysis of variance and Scheffe's post hoc test (p<0.05). Greater histological alterations were found in the medicated and exercised animals, with a greater frequency of occurrence as well. The histochemical analysis revealed that the medicated groups had fibers with more intensive mitochondrial activity alongside fibers with an absence of reaction. The morphometric analysis revealed no significant differences between groups. It is suggested that simvastatin is a medication that leads to the occurrence of muscle injury and its administration in association with physical activity may exacerbate these injuries. This finding may be related to cellular respiration.

Nutritional Responses of Rats to Diets Based on Chickpea (Cicer arietinum L.) Seed Meal or Its Protein Fractions

The aim of this study was to isolate the protein fractions from chickpea, var. IAC-Marrocos, as well as to evaluate its in vivo nutritional protein quality. Among the proteins, albumins showed better nutritional value in the in vivo assays and amino acid contents, despite their higher trypsin inhibitor contents. Trypsin inhibitors were found to be heat labile in all samples, but the digestibility results for unheated and heated flour and albumins suggest that their contents are not very decisive. The PER values for casein (not supplemented) were very similar to those of heated flour and unheated or heated albumin and total globulins. The albumin and glutelin fractions showed the best results for PDCAAS, however, lower than those of casein. Despite the high digestibility of the globulin the very low essential amino acid content lowered its PDCAAS, and it had the lowest values.

Increased glial-derived neurotrophic factor in the small intestine of rats infected with the tapeworm, Hymenolepis diminuta

The neurotrophin, glial-derived neurotrophic factor (GDNF), is essential for the development of the enteric nervous system (ENS) in both the embryo and neonate and may be important for maintenance and plasticity of ENS. The tapeworm, Hymenolepis diminuta, altered the number of cells containing GNDF in the host's jejunum and ileum. Numbers and locations of GDNF-containing cells were determined by applying monoclonal anti-GDNF antibody to intestinal segments collected from infected and uninfected age-matched rats during the initial 34 days post-infection (dpi). Most cells staining positive for GDNF were present in the lamina propria of the jejunum and ileum from both infected and uninfected rats. The co-localization of staining by the antibodies, anti-GDNF and anti-ED2 (a nuclear specific antibody for resident macrophages) indicated that at least 74% of the cells staining for GDNF were macrophages. Mast cells did not stain with the anti-GDNF antibody. The increased number of GDNF+ cells in the infected rat intestine suggests that this neurotrophin may play a role in the neural and mucosal responses to lumenal tapeworm infection.

Alterations in the intestinal wall due to protein malnutrition in rats. Evaluation of the rupture strength and the tissue's collagen

OBJETIVO: Avaliar o efeito da desnutrição protéica na parede intestinal do rato através da medida de força de ruptura e dosagem do colágeno tecidual no íleo e cólon distal. MÉTODOS: Foram utilizados 120 ratos, pesando em média 100g, que receberam durante 07 dias uma dieta padrão, contendo 20% de caseína para adaptação dos animais as condições do biotério. Após esse período os animais foram divididos em dois grupos de 60, o controle denominado grupo um que recebeu a dieta padrão, e o grupo teste denominado grupo dois, que recebeu dieta hipoprotéica contendo 2% de caseína. Os dois grupos receberam suas respectivas dietas por um período de 21 dias. Após esse período iniciou-se o sacrifício seqüencial dos animais em ambos os grupos, em número de 12 animais em cada momento, correspondendo ao dia Zero (MO), 4º dia (M1), 7º dia (M2), 14º dia (M3), e 21º dia (M4) sendo mantida a mesma dieta até o final do sacrifício. em cada momento foram avaliados o peso corpóreo, albumina sanguínea, hidroxiprolina tecidual, relação hidroxiprolina/proteína tecidual e a força de ruptura no segmento ileal e cólico dos animais. RESULTADOS: Observou-se que a força de ruptura do segmento ileal e do cólon distal foi menor nos animais desnutridos (Grupo 2). A perda da resistência mecânica foi maior no segmento do cólon distal do que no segmento ileal, provavelmente pela menor concentração do colágeno tecidual no cólon distal. CONCLUSÃO: A desnutrição protéica induz a diminuição da resistência mecânica no íleo e no cólon distal associado a diminuição do colágeno tecidual na parede intestinal.

Effects of hypertension on maternal adaptations to pregnancy: experimental study on spontaneously hypertensive rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of low fat and babassu fat diets on nutritional status in obstructive cholestasis in young rats

OBJETIVO: Testar os efeitos de uma dieta com baixo teor de gordura comparada a uma dieta com gordura de babaçu sobre o estado nutricional em ratos jovens com colestase obstrutiva. MÉTODOS: Submetemos 40 ratos divididos em quatro grupos de 10 animais a partir do P21 (21º dia pós-natal) até o P49 a dois dos seguintes tratamentos: ligadura e ressecção do ducto biliar comum ou operação simulada e dieta com baixo teor de gordura (óleo de milho fornecendo 4,5% da quantidade total de calorias) ou dieta com gordura de babaçu (essa gordura fornecendo 32,7% e óleo de milho fornecendo 1,7% da quantidade total de calorias). Foi mensurado o ganho de peso a cada 4 dias do P25 ao P49. A função de crescimento de Verhulst foi ajustada aos valores de ganho de peso. A velocidade e a aceleração de crescimento nos mesmos momentos foram estimadas usando a mesma equação. Foram mensurados: quantidade de ração ingerida e ingestão energética total do P21 ao P49, utilização de energia do P25 ao P49, gordura absorvida e balanço de nitrogênio (BN) do P42 ao P49. A ANOVA com dois fatores e o método de S.N.K para comparações pareadas foram utilizados para estudar os efeitos, sobre as variáveis, da colestase e das dietas e sua interação (p<0,05). RESULTADOS: em ratos com colestase e dieta com baixo teor de gordura, houve maior velocidade de crescimento no P45, maior aceleração de crescimento no P41 e P45, maior utilização de energia, maior percentual de gordura absorvida e maior BN do que em ratos com colestase e dieta com gordura de babaçu. CONCLUSÃO: A dieta com baixo teor de gordura atenua a restrição de crescimento provocada pela colestase e proporciona melhor aproveitamento da dieta e maior incorporação da proteína ingerida do que a dieta com gordura de babaçu.

Adult partner preference and sexual behavior of male rats exposed prenatally to betamethasone

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Treatment with Azadirachta indica in diabetic pregnant rats: Negative effects on maternal outcome

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

In Vivo Effects of Bothrops jararaca Venom on Metabolic Profile and on Muscle Protein Metabolism in Rats

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

Tomato-oleoresin supplement prevents doxorubicin-induced cardiac myocyte oxidative DNA damage in rats

Doxorubicin (DOX) is an efficient chemotherapeutic agent used against several types of tumors; however, its use is limited due to severe cardiotoxicity. Since it is accepted that reactive oxygen species are involved in DOX-induced cardiotoxicity, antioxidant agents have been used to attenuate its side effects. To determine tomato-oleoresin protection against cardiac oxidative DNA damage induced by DOX, we distributed Wistar male rats in control (C), lycopene (L), DOX (D) and DOX+lycopene (DL) groups. They received corn oil (C, D) or tomato-oleoresin (5 mg/kg body wt. day) (L, DL) by gavage for a 7-week period. They also received saline (C, L) or DOX (4 ma/kg body wt.) (D, DL) intraperitoneally at the 3rd, 4th, 5th, and at 6th week. Lycopene absorption was checked by HPLC. Cardiac oxidative DNA damage was evaluated by the alkaline Comet assay using formamidopyrimidine-DNA glycosylase (FPG) and endonuclease III (endo 111). Cardiomyocyte levels of SBs, SBs FPG and SBs Endo III were higher in rats from D when compared to other groups. DNA damage levels in cardiomyocytes from DL were not different when compared to C and L groups. The viability of cardiomyocytes from D or DL was lower than C or L groups (p < 0.01). Lycopene levels (mean +/- S.D. nmol/kg) in saponified hearts were similar between L (47.43 +/- 11.78) and DL (49.85 +/- 16.24) groups. Our results showed: (1) lycopene absorption was confirmed by its cardiac levels; (2) DOX-induced oxidative DNA damage in cardiomyocyte; (3) tomato-oleoresin supplementation protected against cardiomyocyte oxidative DNA damage. (c) 2007 Elsevier B.V. All rights reserved.

Mode of Action of Pulegone on the Urinary Bladder of F344 Rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of castor oil-based polyurethane membranes in rat bone-marrow cell culture

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)