Effect of fipronil on energy metabolism in the perfused rat liver

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

In vivo assessment of genotoxic, antigenotoxic and anticarcinogenic activities of Solanum lycocarpum fruits glycoalkaloidic extract

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

Acute and subacute (28 days) oral toxicity assessment of the oil extracted from Acrocomia aculeata pulp in rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Interaction between the septal area and the subfornical organ in the control of water intake induced by thirst-eliciting procedures

Rats bearing lesions in the septal area followed by lesions in the subfornical organ were submitted to various thirst-eliciting procedures. The rats with hyperdipsia induced by lesions of the septal area drank more water than either during the control period or after lesion of the subfornical organ under the same thirst-eliciting or angiotensin-liberating stimuli (polyethyleneglycol, isoproterenol, water deprivation and ligation of the inferior vena cava). The overdrinking elicited by lesions in the septal area was blocked after lesion of the subfornical organ. Neither hypovolemia, nor hypotension or water deprivation could elicit increased water intake in animals whose subfornical organ had been destroyed. Animals with lesions in the subfornical organ showed decreased water intake after cellular dehydration. The results obtained suggest that the subfornical organ acts as a more important structure than the septal area in the regulation of water intake elicited by angiotensin, with two opposite effects: a direct one facilitating water intake, and an indirect one inhibiting the septal area. The septal area has an inhibitory effect on the subfornical organ and on water intake. © 1980.

Alterations to oxidative stress markers in dogs after a short-term stress during transport

While methods to evaluate antioxidant capacity in animals exist, one problem with the models is induction of oxidative stress. It is necessary to promote a great enough challenge to induce measurable alterations to oxidative parameters while ensuring the protocol is compatible with animal welfare. The aim of the present study was to evaluate caged transport as a viable short-term stress that would significantly affect oxidative parameters. Twenty adult Beagle dogs, maintained on the same diet for 60 d prior to the transport, were included in the study. To simulate the stress, the dogs were housed in pairs in transport cages (1·0 m × 1·0 m × 1·5 m), placed on a truck coupled to a trailer and transported for a period of 15 min. Blood collection was performed immediately before and again 3 h after the transportation to evaluate oxidative parameters in blood serum, including thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), sequestration activity of the radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), protein carbonylation (PC), total sulfhydryl groups (SH), alpha-tocopherol (αToc) and retinol (Ret). PC, SH and αToc were not significantly changed in the study; however, TBARS, TAC and DPPH increased, whereas Ret decreased after the transport. Although the lack of a control group of dogs not submitted to transport is a limitation to be considered, we conclude that the transport model is effective in inducing an antioxidant response in dogs and relevant blood parameters show sensitivity to this proposed model.

Cross-sensitization between testosterone and cocaine in adolescent and adult rats

Cocaine and anabolic-androgenic steroids are substances commonly co-abused. The use of anabolic steroids and cocaine has increased among adolescents. However, few studies investigated the consequences of the interaction between anabolic-androgenic steroids in animals' model of adolescence. We examined the effects of acute and repeated testosterone administration on cocaine-induced locomotor activity in adult and adolescent rats. Rats received ten once-daily subcutaneous (s.c.) injections of testosterone (10mg/kg) or vehicle. Three days after the last testosterone or vehicle injections rats received an intraperitoneal (i.p.) challenge injection of either saline or cocaine (10mg/kg). A different subset of rats was treated with a single injection of testosterone (10mg/kg) or vehicle and three days later was challenged with cocaine (10mg/kg, i.p.) or saline. Immediately after cocaine or saline injections the locomotor activity was recorded during forty minutes. Our results demonstrated that repeated testosterone induced locomotor sensitization to cocaine in adolescent but not adult rats.

Sodium nitrite prevents both reductions in circulating nitric oxide and hypertension in 7-day lead-treated rats

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

Digital venography in ruminants - a review

Digital venography is a contrast angiography technique used to study digital vascularity. The technique is simple to be carried out and can be performed under field conditions using a standard radiographic unit. The venogram examination is used to complement conventional radiographic examinations in animals affected by foot diseases. Discrepancy in the contrast vascular pattern may be observed before the clinical signs of the foot disease. Digital venography studies in ruminants are in smaller number than those in horses. The herein presented review discusses digital venography techniques used in ruminants as well as the differences and similarities between ruminants (cattle, sheep and goat) and horses.

Median lethal concentration of formaldehyde and its genotoxic potential in bullfrog tadpoles (Lithobates catesbeianus)

In order to avoid that contaminated frog farms animals escaping in the environment and become potential vector of emergent diseases, studies with disinfection protocol are strictly necessary. The formaldehyde is one of the compounds tested in fungal disinfection protocols and also used in aquaculture. This study aimed to determine the median lethal concentration (LC50-96h) of formaldehyde in bullfrog tadpoles and to evaluate the possible genotoxic effects in acute exposition. Accordingly, the animals were exposed to formaldehyde in the concentrations of 6, 9, 12, 15, and 18 mg L(-1), and after 96 h blood samples were drawn for the micronucleus (MN) test. The LC50-96h was 10.53 mg L(-1), and the MN frequency increased in proportion to the formaldehyde concentrations, with an estimated frequency in the negative control being 1.35 MN/individual. We concluded that formaldehyde is genotoxic to tadpoles of bullfrogs in the tested concentrations, and the choice of this chemical should be contemplated before its use in animals in captivity.

TNF-alpha and IL-6 immunohistochemistry in rat renal tissue experimentaly infected with Leptospira interrogans serovar Canicola

Leptospirosis is a public health problem worldwide and its etiology remains unclear. Its pathogenesis involves a complex interaction between host and infecting microorganism. The inflammatory reaction that controls the infection process also underscores many pathophysiological events occurring in leptospirosis. We investigated the presence of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in renal tissues by immunohistochemical and histopathological examination in animals experimentally inoculated with Leptospira serovar Canicola. All the tests were carried out 2, 7, 14, 21 or 28 days after inoculation. Although TNF-alpha and IL-6 had been detected in tissues throughout the observation period, these cytokines appeared more intensely during the initial phase of infection. Therefore, both TNF-alpha and IL-6 were associated with the immunopathogenesis of leptospirosis. This profile suggests a high immunocellular response throughout the early infection stages followed by subsequent humoral response.

Expression of matrix metalloproteases-2 and-9 in horse hoof laminae after intestinal obstruction, with or without Hydrocortisone treatment

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

Experimentally induced anachoresis in the periapical region after root canal filling

Anachoresis is the phenomenon through which blood-borne bacteria, dyes, pigments and other materials are attracted and fixed to circumscribed areas of inflammation. This study evaluated the occurrence of anachoresis in the periapical region of dogs submitted to root canal fillings. One hundred and four roots from four dogs were endodontically treated and root canals were filled with zinc-oxide-eugenol cement. Fifty percent were filled up to the dentinocemental junction and the others were overfilled. At 120 days after root canal treatment, experimental bacteremia was induced by intravenous inoculation of 105 CFU Streptococcus pyogenes. The dogs were sacrificed 48 hours and 30 days after the bacteremia. Culture and DNA amplification by PCR revealed the presence of the inoculated bacteria just in periapical tissues of dogs sacrificed 48 hours after bacteremia and not in animals sacrificed after 30 days. AP-PCR fingerprints of recovered colonies of S. pyogenes and the presence of genetic markers of resistance to antimicrobials were similar to the inoculated strain. Endodontically treated periapices seemed to be prone to the occurrence of anachoresis and there was no relationship between the phenomenon and the level of root canal filling.

Legumin from chickpea: hypolipidemic effect in the liver of hypercholesterolemic rats

Purpose – This paper aims to determine the effects of 11S globulin isolated from Chickpea (Cicer arietinum L.) on lipid metabolism in animals subjected to a hypercholesterolemic and hyperlipidemic diet and compared to the drug simvastatin. Design/methodology/approach – Thirty-six male Wistar rats, kept in individual cages and under appropriate conditions, were separated into groups that were fed a normal diet (STD) containing casein as protein source and according to AIN-93G; a high-cholesterol diet (HC), normal diet plus 1 per cent cholesterol and 0.5 per cent cholic acid and 20 per cent coconut oil; HC diet plus the isolated 11S globulin (300 mg/kg/day); and HC diet plus the simvastatin (50 mg/kg/day), both dissolved in saline and administered by gavage for 28 days. After this time, the animals were killed. Findings – The results indicated that the addition of 1 per cent cholesterol and 0.5 per cent cholic acid induced hypercholesterolemia in the animals without interfering with their weight gain. Analyses of total cholesterol (TC), HDL-cholesterol (HDL-C) and triglycerides (TG) in the plasma, and TC and TG in the liver were made. The results show that the protein isolated from chickpea, and given as a single daily dose, did not affect the levels of plasma TC and its fractions, although decreasing the TG levels. Unlike the simvastatin, the chickpea protein significantly reduced TC and TG in the liver relative to HC group. Originality/value – A single daily dose of 11S globulin from chickpea contributed as only as additional 2.8 per cent of dietary protein intake. These findings demonstrate that 11S chickpea protein acts as a functional agent in the lipid metabolism in addition to its nutritional properties.

Spleenic Lymphoma and Hemoperitoneum in Jersey Bull: Clinical and Pathological Aspects

Lymphoma is the most prevalent neoplasia in dairy cattle. The etiology can be viral in animals affected by bovine leukemia virus (BLV) or be classified as primary. Lymphoma can affect several organs and according to the system involved, the clinical signs could manifest themselves in different ways. These tumors can be classified through macroscopic characteristics, histology and immunostaining. This classification can be used to predict prognosis and response to therapy. The aim of this case report was to immunostain and classify the tumor, for which anti-CD4, anti-CD8, anti-CD79 and anti-CD3 markers were used in addition to histopathological findings, in order to classify the tumor. The tumor was positive only for anti-CD3 marker, indicating that it is a tumor of young cells and, in association with histopathology and hematological data, it can be concluded that spleen neoplasia is lymphocytic lymphoma originated from a lymphocytic leukemia.

Virus-Associated Tumours of the Harderian Gland in Laboratory-Reared Voles, Clethrionomys rutilis (Pallas)

Tumors of the Harderian gland occurred frequently in red-backed voles, Clethrionomys rutilus (Pallas), in a captive colony maintained since 1957. Although the tumors became obvious only in animals about a year old and older, early stage changes were histologically evident in glands from younger, clinically normal voles. The tumors ranged in type from poorly differentiated adenoma to adenocarcinoma, with invasion of adjacent tissues and characteristic deformation of the zygomata. Electron micrographs disclosed viral particles in the cytoplasm of glands from clinically normal animals as well as in glands showing malignant changes. The tumor was not observed in arvicoline rodents of other species maintained in the same rooms with the red-backed voles.