Training Effects on the Stress Predictors for Young Lusitano Horses Used in Dressage.

The purpose of this study was to investigate stressful responses during a 6-week training protocol in young Lusitano horses used for dressage. The hypothesis was that the proposed training protocol would improve fitness and ensure the welfare of the animals by reducing stress predictors. Nine 4-year-old horses were evaluated before (M1) and six weeks after (M2) beginning a training protocol. The training program was performed six times per week and included 40−80 min of individually intensity-adjusted preparatory exercises for dressage. For both moments, the horses were examined before (T0) and after (T1) dressage simulation tests (DST), and at 30 (T2) and 240 min (T3) during the recovery period. Blood samples were taken to determine the horses' cortisol levels, total WBC, and neutrophil and lymphocyte counts. All variables were analyzed by one-way ANOVA and Tukey tests, with p ≤ 0.05. After training, there was a significant reduction in cortisol (p = 0.0133), HR (p = 0.0283), total WBC (p < 0.0001), and neutrophil (p < 0.0001) and lymphocyte (p = 0.0341) counts. Other findings included an increase in HRV parameters related to a cardiac vagal modulation. In conclusion, the chosen training protocol led to better fitness as the horses worked more intensively with lower cardiovascular requirements, and they showed blunted cortisol responses at M2. Such data can be used to evaluate performance, but also to predict the welfare of athletic horses.

Glicemia e concentrações séricas de insulina, triglicérides e cortisol em equinos da raça Mangalarga Marchador após exercício físico / Glycemia and serum concentrations of insuline, triglycerides and cortisol in Mangalarga Marchador horses after physical exercise

O presente estudo teve por objetivo avaliar a influência do exercício físico de intensidade submáxima (provas de marcha) sobre as variáveis bioquímicas sanguíneas usadas na avaliação do metabolismo energético em equinos da raça Mangalarga Marchador criados no Estado do Espírito Santo. Para tal foram obtidas amostras de soro e plasma de 15 equinos, da raça Mangalarga Marchador, em quatro momentos assim definidos: antes (T0) e com 5 minutos (T1), 30 minutos (T2) e 2 horas (T3) após o término do exercício. A análise dos resultados demonstrou a não influência do exercício físico imposto sobre a glicose plasmática, com valores médios de 117,1±35,8mg/dL, 122,6±59,6mg/dL, 124,8± 48,6mg/dL e 112,9±49,1mg/dL, e sobre a insulina sérica, com valores de mediana de 6,50mUI/mL, 2,00mUI/mL, 5,85mUI/mL e 11,60mUI/mL, respectivamente, nos tempos T0, T1, T2 e T3. De forma oposta, foi possível observar uma influência significativa sobre triglicérides séricos, com valores médios de 25,4±14,9mg/dL, 42,3±17,8mg/dL, 31,4±17,7mg/dL e 25,1±15,1mg/dL, e sobre o cortisol sérico, com valores médios de 7,46±4,37mg/dL, 12,45±3,08mg/dL, 11,40±2,52mg/dL e 6,89±1,78mg/dL, respectivamente nos tempos T0, T1, T2 e T3. A interpretação destes resultados permitiu concluir que a marcha elevou as concentrações séricas de triglicérides e cortisol. Também foi possível destacar que, por tais valores encontrarem-se dentro de intervalos fisiológicos, os equinos usados estavam aptos ao nível de exercício físico imposto na ocasião.

The aim of this study was evaluate the influence of physical exercise of submaximal intensity (marcha gait) on biochemical variables used for the evaluation of energetic metabolism in Mangalarga Marchador horses trained in Espirito Santo, Brazil. Serum and plasma samples were obtained from 15 horses in four different moments: before (T0), 5 minutes (T1), 30 minutes (T2) and 2 hours (T3) after the exercise. Results showed that the imposed exercise did not influence plasmatic glucose, with mean values of 117.1±5.8g/dL, 122.6±59.6mg/dL, 124.8±48.6mg/dL and 112.9±49.1mg/dL, and serum insuline, with median values of 6.50mUI/mL, 2.00mUI/mL, 5.85mUI/mL and 11.60mUI/mL, respectively on the moments T0, T1, T2 and T3. Differently, it was possible to observe a positive influence of the exercise over serum triglycerides, with mean values of 25.4±14.9mg/dL, 42.3±17.8mg/dL, 31.4±17.7mg/dL and 25.1±15.1mg/dL, and serum cortisol, with mean values of 7.46±4.37mg/dL, 12.45±3.08mg/dL, 11.40±2.52mg/dL and 6.89±1.78mg/dL, respectively on the moments T0, T1, T2 and T3. It was possible to conclude that the marcha gait leaded to an elevation of serum triglycerides and cortisol levels. Also, as the values found were within reference levels, it was possible to conclude that the horses were used to this physical activity imposed on the occasion.

Lactacidemia e concentrações séricas de aspartato aminotransferase e creatinoquinase em equinos da raça quarto de milha usados em provas de laço em dupla / Influence of physical exercise on serum activities of AST and CK and plasma concentration of lactate in quarter horses submitted to team roping

O presente estudo teve por objetivo avaliar a influência do exercício físico de alta intensidade e curta duração (provas de laço em dupla) sobre a lactacidemia e as concentrações séricas de aspartato aminotransferase (AST) e creatinoquinase (CK) em equinos durante competição realizada no estado do Espírito Santo. Para tal foram obtidas amostras de soro e plasma de 20 equinos, da raça Quarto de Milha ou mestiços, em três momentos assim definidos: no repouso, uma semana antes da prova atlética, já com o animal em treinamento (T0); antes da prova atlética (T1) e imediatamente após o término da mesma (T2). As referidas amostras foram encaminhadas ao Laboratório Clínico do Centro Universitário Vila Velha (UVV) para as análises. Na avaliação da lactacidemia, os resultados registrados nos momentos T0, T1 e T2 foram, respectivamente, de 0,49±0,24mmol/L, 0,93±0,16mmol/L e 9,86±2,09mmol/L. Na avaliação da atividade sérica de AST, os resultados registrados nos momentos T0, T1e T2 foram, respectivamente, de 189,1±43,6 UI/L, 210,2±46,7 UI/L e 173,1±33,5 UI/L. Por fim, a avaliação da atividade sérica da CK nos momentos T0,T1 e T2 foram,respectivamente, de 110,9±35,2 UI/L, 51,8±15,4 UI/L e 88,2±33,5 UI/L. A análise dos resultados demonstrou que o exercício físico imposto levou ao aumento significativo de lactato plasmático e CK sérica e não alterou o AST sérico e que a interpretação destes resultados permitiu concluir que os equinos usados estavam aptos ao nível de exercício físico imposto.

The aim of the present study was to evaluate the effects of high intensity and short duration physical exercise (roping team competition) on plasma lactate and serum AST and CK concentrations in horses during competition at Espírito Santo state, Brazil. Blood samples were obtained from 20 Quarter Horses, or cross-bred, in three moments: (1) at rest, one week before the competition, with the animals being trained, (2) just before the competition, and (3) immediately after the exercise. The samples were sent to Laboratório Clínico do Centro Universitário Vila Velha for analysis. Plasma lactate concentrations were 0.49±0.24mmol/L, 0.93±0.16mmol/L e 9.86±2.09mmol/L, respectively, on the moments rest and immediately before and after the exercise. Serum concentrations of AST were 189.1±43.6 IU/L, 210.2±46.7 IU/L e 173.1±33.5 IU/L, respectively, on the moments rest and immediately before and after the exercise. Finally, serum concentrations of CK were 110.9±35.2 IU/L, 51.8±15.4 IU/L and 88.2±33.5 IU/L, respectively, on the moments rest and immediately before and after the exercise. Results showed that the imposed physical exercise leaded to a significant elevation of plasma lactate and serum CK without alteration on AST. It was possible to conclude that horses were adapted to the level of exercise performed.

Aryl hydrocarbon receptor polymorphism modulates DMBA-induced inflammation and carcinogenesis in phenotypically selected mice.

We tested the role of aryl hydrocarbon receptor (Ahr) gene polymorphism in the inflammatory response and in skin and lung tumorigenesis in 2 lines of mice phenotypically selected for maximum or minimum acute inflammatory reaction (AIRmax and AIRmin, respectively). Following 7,12-dimethylbenz[a]anthracene (DMBA) treatment, AIRmin but not AIRmax mice showed early skin reactions and eventually developed malignant skin tumors and lung adenocarcinomas. In skin tissue, transcript levels of IL1beta, Tnf, Il6, Tgfbeta1 and Cyp1b1 genes were upregulated in AIRmin but not AIRmax mice, consistent with the inflammatory responses to the carcinogen. These findings appeared to be related to the homozygosity status of the Ahr functional A375V polymorphism, which influences the binding capability of the receptor for DMBA: the 375A allele, encoding the high-affinity ligand-binding receptor (Ahr(b1)), segregated in AIRmin mice, whereas AIRmax mice carried the 375V, corresponding to the low-affinity binding receptor (Ahr(d)), to DMBA. The differential segregation of Ahr functional Ahr(d)versus Ahr(b1) alleles in AIRmax and AIRmin suggests a role for the Ahr gene in the control of inflammatory responsiveness and tumor development of these mouse lines.