Responses to anaesthesia with essential oil (EO) of Aloysia triphylla (135 and 180 mg L−1) and tricaine methanesulfonate (MS222) (150 and 300 mg L−1) were assessed in silver catfish. Exposure to the anaesthetics elicited a stress response in the species. In the case of MS222, it was displayed as a release of cortisol into bloodstream, elevation in hematocrit and plasma ion loss. The EO presented cortisol‐blocking properties, but increased haematocrit and disturbances of hydromineral balance were observed. Liver antioxidant/oxidant status of EO and MS222‐anaesthetized silver catfish was also estimated. The synthetic anaesthetic induced lipoperoxidation, notwithstanding increased catalase contents, whereas the naturally occurring product was capable of preventing the formation of lipid peroxides, possibly due to combined actions of catalase and glutathione‐S‐transferase. Anaesthetic efficacy was also tested via induction and recovery times. Overall, the promising results obtained for the physiological parameters of the EO‐treated fish counterbalanced the slight prolonged induction time observed for 180 mg L−1. As for 135 mg L−1, both induction and recovery times were lengthy; despite that, the EO was able to promote oxidative protection and mitigate stress. None of the MS222 concentrations prompted such responses concomitantly.

LIPUS reduced aspects of the inflammatory process following an acute incisional muscular lesion.

Este estudo verificou a eficiência de infusão de duas plantas usadas na medicina popular, Syzygium jambolanum (Sj) e Bauhinia candicans (Bc). Sessenta (60) ratos adultos, machos, da linhagem Wistar, pesando entre 220 e 240g, foram submetidos à indução de Diabetes mellitus insulino dependente (DMID) com Aloxano. O estudo foi dividido em dois experimentos. No primeiro, 15 ratos receberam a administração de Aloxano na dosagem de 40mg/kg em dose única e no segundo, 60mg/kg uma vez ao dia, durante três dias, ambos por via intraperitonial. A hiperglicemia foi confirmada no terceiro dia de cada experimento. Após esta confirmação, os animais foram divididos aleatoriamente em três grupos de cinco e quinze animais para o primeiro e segundo experimento, respectivamente. O grupo 1 (C) serviu como controle, o grupo 2 (TI) recebeu infusão de Sj "ad libitum" como fonte líquida e o grupo 3 (TII) recebeu infusão de Bc, por um período de 21 e 40 dias, para o primeiro e segundo experimento, respectivamente. A colheita de sangue foi realizada por punção do plexo venoso retro-orbitário com os animais anestesiados, nos dias 3, 9, 16 e 23 do primeiro experimento e nos dias 3, 16, 24 e 40 do segundo. Após vinte e um dias da fase de tratamento, o grupo TI do primeiro experimento apresentou marcante redução de hiperglicemia (P < 0,001). Esta mesma observação foi verificada no grupo TI do segundo experimento aos dezesseis dias da fase de tratamento (P < 0,004), estendendo-se até os quarenta dias (P < 0,0001), quando comparado ao grupo controle. Simultaneamente, sinais clínicos de DMID, como polifagia e polidipsia foram reduzidos neste grupo. O colesterol plasmático demonstrou aumento moderado somente nos animais do segundo experimento, não sendo observado o efeito do tratamento com infusão Sj e Bc sobre a colesterolemia dos animais em estudo. No 40º dia de ambos os experimentos, os animais foram eutanasiados e foram colhidas amostras de pâncreas e fígado para avaliação histopatológica. A análise histopatológica das amostras de pâncreas e fígado do experimento I não demonstrou diferença entre os grupos tratados e o grupo C. No entanto, no experimento II, nove em dez amostras do grupo C e cinco em nove amostras do grupo TII apresentaram necrose de células das ilhotas de Langerhans do pâncreas, enquanto que somente duas das nove amostras do grupo TI apresentaram necrose de células das ilhotas de Langerhans. Os resultados obtidos neste estudo permitem concluir que o uso de infusão da planta Sj como substituto da água é eficiente no controle da hiperglicemia e redução dos sinais clínicos do DMID como polifagia e polidipsia, enquanto que o tratamento com infusão de Bc não possui o mesmo efeito.

In this study, the influence of temperature variation on the blood and oxidative stress parameters of pacu Piaractus mesopotamicus juveniles was evaluated. Fish were subjected to gradual changes of temperature, over 5 days, by 24°C until reaching to experimental temperatures 18, 21, 24 (control), 27 and 30°C. There were significant differences (p < .05) in glucose and lactate of blood in both the haematological relationships and oxidative stress parameters. Glucose levels increased at 30°C and decreased at 21°C. Lactate levels were highest at 18°C. While the haematocrit was higher at all altered temperatures, haemoglobin levels decreased at 21°C and increased at 30°C, causing alterations in haematimetric indices. In the liver, glutathione‐S‐transferase (GST) activity was reduced at 18°C while antioxidant capacity against peroxyl radicals (ACAP) was highest at 30°C. Thiobarbituric acid reactive substances (TBARS) increased at 18, 21 and 27°C. In the muscle, ACAP decreased at 27 and 30°C and TBARS increased at 30°C. The results indicate that the species shows sensitivity to temperature variations. Accordingly, we conclude that with short‐term temperature variations >3°C, it is possible to induce higher alterations in the observed parameters in pacu juveniles.

Rhamdia quelen morphophysiological responses to propofol sedation were examined. The purpose was to investigate whether propofol would be a suitable drug to be used in fish transport procedures. Fish were exposed to 0, 0.4 or 0.8 mg L(-1) propofol for 1, 6 or 12 h in 40 L tanks, simulating open transport systems. Propofol was able to prevent the peak of cortisol levels experienced by the group exposed to 0 mg L(-1) propofol at 1 h. At 0.4 mg L(-1), propofol also preserved the stability of hematological (hematocrit, red blood cell count, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration), morphological (red blood cell area), biochemical (cortisol, glucose, lactate, total protein, ammonia, urea, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase) and hydromineral (Na(+), Cl(-) and K(+) plasma levels) indicators of stress. Such results suggest that sedation with propofol at 0.4 mg L(-1) is suitable for R. quelen transport.

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| Sociedade Brasileira de Zoologia | www.sbzoologia.org.br | www.scielo.br/zool All content of the journal, except where identified, is licensed under a Creative Commons attribution-type BY-NC.Dissolved organic matter, an integral part of all ecosystems, results from the decay of plant and animal debris (THURMAN 1985). It comprises humic, fulvic, and other organic acids, and is usually quantified as dissolved organic carbon (DOC) (WOOD et al. 2011). DOC is known to positively regulate several biotic/abiotic processes (STEINBERG et al. 2007, WOOD et al. 2011. In blackwaters, such as those found in forest streams in the Amazon, coastal lagoons in southeastern Brazil, Finnish and Swedish lakes, and Canadian wetlands, DOC may range from 10 to 300 mg CL -1 , while its average content in freshwater systems elsewhere is 0.5-4.0 mg CL -1 (THURMAN 1985, KÜCHLER et al. 2000, FARJALLA et al. 2009). The high levels of DOC account for the acidity of the aquatic environment. In order to thrive in acidic environments, organisms need a certain degree of specialization in their osmoregulatory organs (MATSUO & VAL 2007).Low pH (pH 4-5) induces ion loss (ZAIONS & BALDISSEROTTO 2000, 2003, BOLNER & BALDISSEROTTO 2007, MATSUO & VAL 2007, DUARTE et al. 2013) and the interference with gill ionoregulatory mechanisms may also trigger hematological disturbances. Ionic dilution, potentiated by the plasma acidosis prompted by H + entry, affects body fluid distribution. This could promote reduction in plasma volume, swelling of erythrocytes or splenic contraction, resulting in elevation of the hematocrit (MILLIGAN & WOOD 1982). Despite being highly responsible for the acidic nature of blackwaters, there is evidence that DOC protects native fish from the deleterious effects of low pH, reducing ion loss , 2003, MATSUO & VAL 2007. According to some studies, the occurrence of various charged functional groups in the heterogeneous compounds of DOC may change fundamental properties of the gill epithelium, such as the transepithelial potential, thus altering membrane permeability and stimulating ion uptake (WOOD et al. 2011). Humic acid also reduces respiratory stress in fish exposed to slightly acidic water, but increases it at more acidic waters (HOLLAND et al. 2014) and decreases lipid peroxidation and modulates the antioxidant system (RIFFEL et al. 2014). In opposition to the several findings regarding the effects of DOC on ionoregulatory disturbances, respiratory stress and antioxidant system, no evidence has been documented about its influence on the hematology of fish subjected to acidic pH. 4.2, erythrocytes of fish not exposed to HA were smaller, an effect that was partially offset by the presence of HA, since the values at pH 7.0 were higher. Although HA showed some positive effects changes in hematological and plasma K + ª in silver catfish caused by exposure to acidic pH, the overall findings suggest that HA does not protect this species against acidic pH because it increased mortality and Cl -loss at pH 4.0. Effect of humic acid on su...