Rat model of depending prostaglandin renal state: Effect of ketoprofen

Introduction .The renal prostaglandins (PGs), vasodilators, preserve kidney function during increased activity of the renin-angiotensin system or renal sympathetic nerves (renal PG-dependent state [RPGD]). Ketoprofen (Ket) inhibits cyclooxygenase and, therefore, the synthesis of PGs. The aim of this study was to determine, in the rat, the action of Ket in the renal histology and function in a RPGD state (stress of anesthesia and hemorrhage). Material and Methods . Twenty male Wistar rats, anesthetized with sodium pentobarbital, were randomly divided into two groups: G1-control ( n = 10) and G2-Ket ( n = 10) submitted to arterial hemorrhage of 30% of volemia (estimated as 6% of body weight) three times (10% each 10 min), 65 min after anesthesia. G2 animals received Ket, 1.5 mg. kg -1 , venously, 5 min after anesthesia and 60 min before the first hemorrhage moment (first moment of the study [M1]). Medium arterial pressure (MAP), rectal temperature (T), and heart rate were monitored. G1 and G2 received para-aminohippurate sodium (PAH) and iothalamate sodium (IOT) solutions during the entire experimental time in order to determine clearance of PAH (effective renal plasma flow [ERPF]) and clearance of IOT (glomerular filtration rate [GFR]) without urine collection (determination of blood concentrations of PAH and IOT through the high-performance liquid chromatography), filtration fraction (FF), and renal vascular resistance (RVR). The animals were sacrificed in M3, 30 min after the third hemorrhage (M2) moment, and the kidneys and blood collected during the hemorrhage periods were utilized for histological study and determinations of hematocrit (Ht), serum creatinine (S Cr ), ERPF, GFR, FF, and RVR, respectively. Results . There were significant reductions of MAP, T, and Ht and a significant increase of S Cr . During the experiment, ERPF and GFR did not change, but ERPF was always higher in G1 than in G2. Ket did not alter FF, which increased in G1 over the duration of experiment. The Ket group had significantly higher RVR than the control group. The histology verified that both G1 and G2 were similar for tubular dilation and necrosis, but they were significantly different for tubular degeneration: G1 > G2. Conclusion . The changes observed in kidney histology probably were determined by hemorrhage and hypotension. Ket inhibited the synthesis of PGs and diminished tubular degeneration.

Efeitos do halotano, isoflurano e sevoflurano sobre a função renal em cães sob pinçamento aórtico infra-renal

JUSTIFICATIVA E OBJETIVOS: O pinçamento infra-renal da aorta abdominal pode produzir alterações renais. O objetivo do estudo foi avaliar os efeitos do halotano, isoflurano e sevoflurano sobre a função renal, em cães submetidos a pinçamento aórtico infra-renal. MÉTODO: O estudo aleatório foi realizado em 30 cães, distribuídos em três grupos, de acordo com o anestésico halogenado utilizado durante a anestesia, em concentrações equipotentes de 0,75 CAM: GH (n = 10) - halotano a 0,67%; GI (n = 10) - isoflurano a 0,96%; e GS (n = 10) - sevoflurano a 1,8%. em todos os animais foi realizada ligadura infra-renal da aorta, por período de 30 minutos. Os atributos renais foram estudados nos momentos: C (controle), após 15 (Ao15) e 30 (Ao30) minutos de pinçamento aórtico, e após 15 (DAo15) e 30 (DAo30) minutos do despinçamento aórtico. RESULTADOS: A depuração de água livre foi menor nos grupos GI e GS, em relação ao GH, após o despinçamento aórtico (p < 0,05). Durante o pinçamento aórtico, nos três grupos, houve aumento do débito urinário, da excreção urinária de sódio e da depuração de sódio, e diminuição da osmolaridade urinária (p < 0,05). A resistência vascular renal e a fração de filtração aumentaram somente em GS (p < 0,05), enquanto a excreção fracionária de sódio aumentou em GH e GI (p < 0,05). Após o despinçamento aórtico, houve normalização dos atributos que haviam se alterado, com exceção da osmolaridade urinária, que continuou em níveis menores do que os do controle em todos os grupos (p < 0,05). A resistência vascular renal e a fração de filtração continuaram mais elevadas em GS, acompanhadas por diminuição do fluxo sangüíneo renal e da depuração de para-aminohipurato de sódio (p < 0,05). CONCLUSÕES: No cão nas condições experimentais empregadas, a inalação de halotano e isoflurano a 0,75 CAM, mas não de sevoflurano, atenuou a principal alteração após o pinçamento infra-renal da aorta, que é o aumento da resistência vascular renal.

Efeitos do halotano, isoflurano e sevoflurano nas respostas cardiovasculares ao pinçamento aórtico infra-renal: estudo experimental em cães

JUSTIFICATIVA E OBJETIVOS: O pinçamento infra-renal da aorta abdominal pode produzir alterações hemodinâmicas. O objetivo do estudo foi avaliar os efeitos do halotano, isoflurano e sevoflurano sobre a função cardiovascular, em cães submetidos à pinçamento aórtico infra-renal. MÉTODO: O estudo aleatório foi realizado em 30 cães, distribuídos em três grupos, de acordo com o anestésico halogenado utilizado durante a anestesia, em concentrações equipotentes de 0,75 CAM: GH (n=10) - halotano a 0,67%; GI (n=10) - isoflurano a 0,96%; e GS (n=10) - sevoflurano a 1,8%. em todos os animais foi realizada ligadura infra-renal da aorta, por período de 30 min. Os atributos hemodinâmicos foram estudados nos momentos: C (Controle), Ao15 e Ao30, respectivamente após 15 e 30 minutos do pinçamento aórtico, e DAo e DAo15, respectivamente, imediatamente e após 15 min do despinçamento aórtico. RESULTADOS: Durante o pinçamento aórtico houve, em todos os grupos, aumento das pressões arterial média e do átrio direito, e dos índices cardíaco, sistólico e de trabalho sistólico dos ventrículos direito e esquerdo. A pressão da artéria pulmonar aumentou em GI e GS e a pressão pulmonar ocluída em GH e GI. Após o despinçamento aórtico, houve normalização dos atributos que haviam se elevado, com exceção dos índices cardíaco e sistólico, que continuaram elevados, acompanhados de diminuição do índice de resistência vascular sistêmica. Não houve diferença significante entre os grupos em relação aos atributos estudados, com exceção da freqüência cardíaca que foi sempre menor em GH, em relação aos demais grupos, durante o pinçamento e despinçamento aórtico. CONCLUSÕES: No cão, nas condições experimentais empregadas, a inalação do halotano, isoflurano e sevoflurano em concentrações equipotentes (0,75 CAM) não atenua as respostas cardiovasculares ao pinçamento aórtico infra-renal.

Efeitos da clonidina nas respostas cardiovasculares ao pinçamento aórtico infra-renal: estudo experimental no cão

JUSTIFICATIVA E OBJETIVOS: O pinçamento aórtico infra-renal pode determinar alterações cardiovasculares. A clonidina, um alfa2-agonista, determina bradicardia e diminuição da pressão arterial. O objetivo do estudo foi avaliar os efeitos da clonidina sobre a função cardiovascular, em cães submetidos a pinçamento aórtico infra-renal. MÉTODO: O estudo aleatório foi realizado em 16 cães, distribuídos em dois grupos: G Controle - sem a utilização de clonidina e G Clon - clonidina, na dose inicial de 5 µg.kg-1, por via venosa, imediatamente antes do pinçamento aórtico infra-renal, seguido de 2 µg.min-1.m² até o final do estudo. em todos os animais foi realizada ligadura infra-renal da aorta, por 45 minutos. Os atributos hemodinâmicos foram estudados nos momentos C (controle), após 10 (Ao10) e 25 (Ao25) minutos do pinçamento aórtico, e após 10 (DAo10) e 25 (DAo25) minutos do despinçamento aórtico. RESULTADOS: Durante o pinçamento aórtico, houve diferença significante entre os grupos, em relação à freqüência cardíaca, pressão arterial média e índice cardíaco (G Controle > G Clon). Após o despinçamento aórtico houve diferença significante entre os grupos, em relação à freqüência cardíaca (G Controle > G Clon) e pressões do átrio direito e da artéria pulmonar ocluída (G Clon > G Controle). Durante o pinçamento aórtico, houve nos dois grupos, aumento significante das pressões de átrio direito e artéria pulmonar ocluída, dos índices sistólico e do trabalho sistólico do ventrículo esquerdo, e diminuição do índice de resistência vascular pulmonar. No grupo controle houve aumento significante das pressões arterial média e da artéria pulmonar, e dos índices cardíaco e do trabalho sistólico do ventrículo direito. No grupo clonidina, houve diminuição significante da freqüência cardíaca. Após o despinçamento aórtico, houve nos dois grupos: diminuição significante da freqüência cardíaca e pressão arterial média, enquanto os valores das pressões do átrio direito e índice sistólico continuaram elevados. No grupo controle, os valores do índice de trabalho sistólico do ventrículo direito continuaram elevados enquanto os valores do índice cardíaco retornaram a valores próximos aos do controle. No grupo clonidina, os valores das pressões do átrio direito e da artéria pulmonar ocluída, e o índice sistólico, continuaram significantemente elevados. CONCLUSÕES: No cão, nas condições experimentais empregadas, a administração venosa contínua de clonidina atenua as respostas cardiovasculares decorrentes do pinçamento aórtico infra-renal.

The Effects of 6% Hydroxyethyl Starch-Hypertonic Saline in Resuscitation of Dogs with Hemorrhagic Shock

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alterations in myocardial collagen content affect rat papillary muscle function

We investigated the influence of myocardial collagen volume fraction (CVF, %) and hydroxyproline concentration (mu g/mg) on rat papillary muscle function. Collagen excess was obtained in 10 rats with unilateral renal ischemia for 5 wk followed by 3-wk treatment with ramipril (20 mg . kg(-1) . day(-1)) (RHTR rats; CVF = 3.83 +/- 0.80, hydroxyproline = 3.79 +/- 0.50). Collagen degradation was induced by double infusion of oxidized glutathione (GSSG rats; CVF 5 2.45 +/- 0.52, hydroxyproline = 2.85 +/- 0.18). Nine untreated rats were used as controls (CFV = 3.04 +/- 0.58, hydroxyproline = 3.21 +/- 0.30). Active stiffness (AS; g . cm(-2) . %L-max(-1)) and myocyte cross-sectional area (MA; mu m(2)) were increased in the GSSG rats compared with controls [AS 5.86 vs. 3.96 (P< 0.05); MA 363 +/- 59 vs. 305 +/- 28 (P< 0.05)]. In GSSG and RHTR groups the passive tension-length curves were shifted downwards, indicating decreased passive stiffness, and upwards, indicating increased passive stiffness, respectively. Decreased collagen content induced by GSSG is related to myocyte hypertrophy, decreased passive stiffness, and increased AS, and increased collagen concentration causes myocardial diastolic dysfunction with no effect on systolic function.

Nocardiosis: an overview and additional report of 28 cases in cattle and dogs

A caracterização fenotípica, perfil de sensibilidade aos antimicrobianos e aspectos clínico-epidemiológicos foram avaliados em 28 linhagens de Nocardia isoladas de 19 casos de mastite, oito lesões tegumentares e um caso de pneumonia em cão. Foram utilizados no diagnóstico métodos microbiológicos, bioquímicos, citológicos e microscopia eletrônica de varredura. Nocardia asteroides tipo IV, N. otitidiscaviarum,N. nova (tipo III) e N. farcinica (tipo V) foram isoladas do leite de vacas com mastite, de material de lavado transtraqueal e de lesões cutâneas de cães. Nocardiose mamária bovina foi diagnosticada predominantemente sob a forma clínica, em propriedades com precárias condições de higiene na pré e pós-ordenha, e inadequado procedimento de terapia intramamária. Nocardiose canina foi diagnosticada comumente em animais co-infectados com o vírus da cinomose. Sulfametoxazole/trimetoprim (92,8%), amicacina (92,8%) e ceftiofur (92,8%) foram os antimicrobianos mais efetivos frente às linhagens de Nocardia. Resistência múltipla a três ou mais e cinco ou mais antimicrobianos foram observadas, respectivamente, em dez (35,7%) e três (10,7%) linhagens, notadamente frente à cloxacilina, cefoperazona e ampicilina. A caracterização de espécies (tipo), aspectos clínico-epidemiológicos, diagnóstico, resistência múltipla aos antimicrobianos e reflexos em saúde pública de linhagens de Nocardia isoladas de bovinos e cães no Brasil foram discutidos. Foi destacada a similaridade entre as espécies de Nocardia isoladas de animais e do homem, e a primeira descrição no Brasil de N. otitidiscaviarum na etiologia da mastite bovina.

Effects of the opiold remifentanil on the arrhythmogenicity of epinephrine in halothane-anesthetized dogs

Opioids may exert a protective effect against ventricular arrhythmias via a vagally mediated mechanism. This study evaluated the effects of the opioid remifentanil on arrhythmogenicity of epinephrine during halothane anesthesia. Eight dogs were assigned to 2 treatments in a randomized crossover design, with 1-week intervals between treatments. Anesthesia was maintained with 1.3% end-tidal halothane in oxygen and mechanical ventilation to maintain eucapnia. A constant rate infusion of remifentanil (0.72 mu g/kg/min) was administered throughout the study in the experimental treatment, while control animals received physiologic saline as placebo. The arrhythmogenic dose of epinephrine (ADE), defined as 4 premature ventricular complexes (PVCs) within 15 s, was determined by administering progressively increasing infusion rates of epinephrine (2.5, 5.0, and 10 mu g/kg/min), allowing 20 min intervals between each infusion rate. In both treatments, epinephrine infusions induced bradyarrhythmias and atrioventricular conduction disturbances, which were followed by escape beats and PVCs. In the remifentanil treatment, mean s ADE values (11.3 +/- 4.9 mu g/kg) did not differ from values observed in control animals (9.9 +/- 6.1 mu g/kg). on the basis of the ADE model for assessing the arrhythmogenity of drugs during halothane anesthesia, the present study did not demonstrate a protective effect of remifentanil (0.72 mu g/kg/min) against ventricular arrhythmias in dogs.

Effect of intravenous propofol and remifentanil on heart rate, blood pressure and nociceptive response in acepromazine premedicated dogs

ObjectiveTo investigate the cardiorespiratory, nociceptive and endocrine effects of the combination of propofol and remifentanil, in dogs sedated with acepromazine.Study designProspective randomized, blinded, cross-over experimental trial.AnimalsTwelve healthy adult female cross-breed dogs, mean weight 18.4 +/- 2.3 kg.MethodsDogs were sedated with intravenous (IV) acepromazine (0.05 mg kg-1) followed by induction of anesthesia with IV propofol (5 mg kg-1). Anesthesia was maintained with IV propofol (0.2 mg kg-1 minute-1) and remifentanil, infused as follows: R1, 0.125 mu g kg-1 minute-1; R2, 0.25 mu g kg-1 minute-1; and R3, 0.5 mu g kg-1 minute-1. The same dogs were administered each dose of remifentanil at 1-week intervals. Heart rate (HR), mean arterial pressure (MAP), respiratory rate (f(R)), end tidal CO(2) (Pe'CO(2)), arterial hemoglobin O(2) saturation, blood gases, and rectal temperature were measured before induction, and 5, 15, 30, 45, 60, 75, 90, and 120 minutes after beginning the infusion. Nociceptive response was investigated by electrical stimulus (50 V, 5 Hz and 10 ms). Blood samples were collected for plasma cortisol measurements. Statistical analysis was performed by anova (p < 0.05).ResultsIn all treatments, HR decreased during anesthesia with increasing doses of remifentanil, and increased significantly immediately after the end of infusion. MAP remained stable during anesthesia (72-98 mmHg). Antinociception was proportional to the remifentanil infusion dose, and was considered satisfactory only with R2 and R3. Plasma cortisol concentration decreased during anesthesia in all treatments. Recovery was smooth and fast in all dogs.Conclusions and clinical relevanceInfusion of 0.25-0.5 mu g kg-1 minute-1 remifentanil combined with 0.2 mg kg-1 minute-1 propofol produced little effect on arterial blood pressure and led to a good recovery. The analgesia produced was sufficient to control the nociceptive response applied by electrical stimulation, suggesting that it may be appropriate for performing surgery.

Toad poisoning in three dogs: case reports

Toad poisoning is frequent in dogs, but has been infrequently addressed in published case reports and review articles. Dogs can be poisoned when they bite a toad or otherwise ingest the venom. The venom effects manifest soon after the accident, since the toxin is rapidly absorbed by the mucous membrane of the digestive system. Hospital records of three dogs, diagnosed with toad poisoning, were retrospectively reviewed from January 2005 to July 2007. Poisoned dogs may present only local irritation or systemic signs in the gastrointestinal, cardiac and neurological systems. All three cases presented herein had clinical signs of gastrointestinal alterations including vomiting, sialorrhea and diarrhea. Two dogs developed abnormal cardiac rhythm and two exhibited neurological signs. A poisoned animal requires emergency care and symptomatic therapy with intense monitoring of its clinical parameters. Although there have been reports on the low mortality of dogs poisoned by toads, one animal died even after appropriate therapy. The severity of clinical signs and the risk of death must be considered by the veterinarian.

A polymerase chain reaction for the detection of Brucella canis in semen of naturally infected dogs

The objective was to evaluate a PCR assay for the detection of Brucella canis in canine semen, comparing its performance with that of bacterial isolation, serological tests and PCR assay of blood. Fifty-two male dogs were examined clinically to detect reproductive abnormalities and their serum was tested by the rapid slide agglutination test, with and without 2-mercaptoethanol (2ME-RSAT and RSAT, respectively). In addition, microbiological culture and PCR assays were performed on blood and semen samples. The findings of the semen PCR were compared (Kappa coefficient and McNemar test) to those of blood PCR, culture of blood and semen, RSAT, and 2ME-RSAT. Nucleic acid extracts from semen collected from dogs not infected with B. canis were spiked with decreasing amounts of B. canis RM6/66 DNA and the resulting samples subjected to PCR. In addition, semen samples of non-infected dogs were spiked with decreasing amounts of B. canis CFU and the resulting suspensions were used for DNA extraction and amplification. of the 52 dogs that were examined, the following tests were positive: RSAT, 16 (30.7%); 2ME-RSAT, 5 (9.6%); blood culture, 14 (26.9%); semen culture, 11 (21.1%); blood PCR, 18 (34.6%); semen PCR, 18 (34.6%). The PCR assay detected as few as 3.8 fg of B. canis DNA experimentally diluted in 444.9 ng of canine DNA (extracted from semen samples of noninfected dogs). In addition, the PCR assay amplified B. canis genetic sequences from semen samples containing as little as 1.0 x 10(0) cfu/mL. We concluded that PCR assay of semen was a good candidate as a confirmatory test for the diagnosis of brucellosis in dogs; its diagnostic performance was similar to blood culture or blood PCR. Furthermore, the PCR assay of semen was more sensitive than the 2ME-RSAT or semen culture. Examination of semen by PCR should be included for diagnosis of brucellosis prior to natural mating or AI; in that regard, some dogs that were negative on serological and microbiological examinations as well as blood PCR were positive on PCR of semen. (c) 2007 Elsevier B.V. All rights reserved.

Hemodynamic evaluation of the right portal vein in healthy dogs of different body weights

Background: Doppler ultrasonography is an important tool for evaluating hepatic portal hemodynamics. However, no study in dogs of different body weights, in the range encountered in routine clinical veterinary practice, has been reported. It can be difficult to obtain an ideal insonation angle when evaluating the main portal vein, so evaluation of the right portal vein branch has been described in humans as an alternative. The aim of this study was to analyze, through Doppler ultrasonography, the hemodynamics in the right portal vein branch in dogs of different body weights.Methods: Thirty normal dogs were divided in three groups by weight, in order to establish normal values for mean velocity, flow volume and portal congestion index of the right portal vein branch by means of Doppler ultrasonography.Results: In all dogs ideal insonation angles were obtained for the right portal vein branch. The average velocity was similar in the three groups, but the portal congestion index and the flow volume differed, showing that the weight of the dog can influence these values.Conclusion: Doppler ultrasonography for the evaluation of flow in the right branch of the portal vein could be a viable alternative, or complement, to examining the main vessel segment. This is especially so in those animals in which an ideal insonation angle for examination of the main portal vein is hard to obtain. In addition, the weight of the dog must be considered for the correct evaluation of the portal system hemodynamics, particularly for portal blood flow and the congestion index.

Differential alterations in the activity of matrix metalloproteinases within the nervous tissue of dogs in distinct manifestations of visceral leishmaniasis

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

Estresse oxidativo e aumento da apoptose em neutrófilos de cães com azotemia pré-renal

O presente trabalho tem como objetivo testar a hipótese de que, à semelhança do que ocorre na uremia, cães com azotemia pré-renal sofrem estresse oxidativo, o qual está relacionado com alterações do metabolismo oxidativo e apoptose dos neutrófilos. Para tal, foi determinada a peroxidação lipídica pela quantificação do malondialdeído (MDA) e o status antioxidante total do plasma de 15 cães normais e 10 com azotemia pré-renal, correlacionando-os com a produção de superóxido e o índice apoptótico dos neutrófilos. As determinações do MDA e do status antioxidante total foram estabelecidas empregando-se um conjunto de reagentes comerciais. Por meio de citometria de fluxo capilar, a produção de superóxido e a apoptose de neutrófilos isolados de sangue periférico foram determinadas utilizando-se a sonda hidroetidina e o sistema anexina V-PE, respectivamente. Cães azotêmicos (26,29±5,32g/L) apresentaram menor concentração (p=0,0264) do antioxidante albumina em relação ao grupo-controle (30,36±3,29g/L) e também uma menor (p=0,0027) capacidade antioxidante total (2,36±0,32 versus 2,73±0,24mmol/L), enquanto não houve alteração da peroxidação lipídica plasmática e da produção de superóxido neutrofílica. Concluiu-se que, à semelhança do que ocorre na uremia, condições azotêmicas pré-renais no cão causam estresse oxidativo e aceleração da apoptose dos neutrófilos.

Evaluation of TNF-alpha, IL-4, and IL-10 and parasite density in spleen and liver of L. (L.) chagasi naturally infected dogs

Dogs are the main domestic reservoirs of L. (L.) chagasi. Once in the vertebrate host, the parasite can cause visceral leishmaniasis, which can also be transmitted to humans. Cytokines are key elements of the host immune response against Leishmania spp. To investigate whether tumor necrosis factor (TNF)-alpha, interleukin (IL)-4 and IL-10 are associated with pattern infection in dogs, these cytokines were quantified in the spleen and liver of dogs naturally infected with L. (L.) chagasi, with or without clinical manifestations, and their levels were correlated with the parasite load verified in these organs. A total of 40 adult dogs naturally infected with L. (L.) chagasi were assessed, together with 12 uninfected control dogs. Samples from spleen and liver were used to determine the cytokine levels by capture ELISA and for quantifying parasite load by real-time PCR. Statistical analysis was performed using the minimum Chi square method and group means were compared using the Tukey test. TNF-alpha, IL-4 and IL-10 levels in infected dogs were higher than in control groups; the liver was the main cytokine-producing organ during infection. The level of splenic TNF-alpha showed correlation with parasite load and may represent an important marker for infection process evolution, with the participation of IL-10. These results may contribute to a clearer understanding of the immune response in dogs infected with L. (L.) chagasi, which may lead to the development of prophylactic or preventive measures for these animals.