Cost of transport, but not gluteus medius and red blood cells monocarboxylate-transporters density differentiated Brazilian Sport Horses at two performance levels.

Cost of transport (COT) and monocarboxylate transporters (MCTs) could affect the ability to perform fast actions during a jumping discipline. This study aimed to compare the COT and evaluate the MCT1, MCT4, and their auxiliary protein CD147 content in the gluteus medius and RBCs of Brazilian sport horses (BH), a breed developed for jumping competitions, with low-level (LL) or intermediate-level (IL) jumping capacities. The physiological difference between the horses was assessed by an incremental jump test (IJT), in which the cost of lactate (COTLAC) and heart rate (COTHR) of running were determined for each animal by the ratio between each variable and the running speed. Western blotting was performed on muscle and RBC membranes to quantify MCT1, MCT4, and CD147. IL showed lower COTLAC and COTHR than LL at all jumping heights. The amount of MCT1, MCT4, and CD147 found in muscle and RBCs were not dependent on performance level. Muscle MCT4 and MCT1 were correlated positively with CD147. We conclude that the relatively small differences between performances did not relevantly influence MCT expression in BH. While MCT analyses are inaccessible for most trainers and veterinarians, the cost of transport measurements is a feasible and sensitive tool to distinguish intermediate and low-level jumping horses.

Differential Expression of Monocarboxylate Transporter 1 and Ancillary Protein CD147 in Red Blood Cells of Show Jumping Horses.

We compare the expression levels of the lactate transporter complex consisting of the lactate transporter, monocarboxylate transporter 1 (MCT1), and its ancillary protein, cluster of differentiation 147 (CD147), in the membranes of red blood cells (RBCs) from two breeds of jumping horses and associate the expression levels of these proteins with their jumping ability. The expression levels of MCT1 and CD147 proteins on the membranes of RBCs collected from 30 show jumping horses of two different breeds were quantified: the Brazilian Sport Horses (n = 17) and the European Warmbloods (n = 13). The levels of MCT1 and CD147 in the RBC membranes were measured by Western blot using horse-specific antibodies. Statistical analyses included unpaired Student t-test and Chi-squared test. According to the expression levels of MCT1 and CD147 proteins, 88% of the Brazilian Sport Horses were categorized as high lactate transporters and the remaining 12% as low lactate transporters. The opposite was found for the European Warmbloods, where most animals (77%) were classified as low lactate transporters and the remaining animals (23%) were classified as high lactate transporters. Brazilian Sport Horses express statistically significantly higher levels of CD147 and MCT1 than European Warmbloods. The classification of horses considering the expression of proteins involved in the ability to transport lactate through the complex MCT1-CD147 seems to be breed dependent, with horses that are able to jump higher obstacles showing lower expression of the MCT1-CD147 complex in their RBCs.

Eye Surface Temperature as a Potential Indicator of Physical Fitness in Ranch Horses.

This study aimed to investigate the use of maximum eye surface temperature (ESTmax), recorded by infrared thermography, as an indicator of physical fitness in ranch horses. Data collection was carried out with 16 horses by recording six physical fitness biomarkers (ESTmax, respiratory rate, creatine kinase activity [CK], and concentrations of total serum protein, plasmatic cortisol, and lactate) before and after a regular working day. We also recorded heart rate during the exercise, exercise duration, average velocity, distance traveled, and air temperature and humidity. The variation between the sampling times was compared by using repeated measures ANOVA or Wilcoxon paired test. The t-test was used to compare ESTmax means of dehydrated and nondehydrated horses. The differences (DIF-) between each variable's sampling times were calculated, and the Spearman's correlation coefficients between DIF-ESTmax and DIF- of other variables were estimated. A hierarchical cluster analysis was used to classify the horses according to their physical fitness. All biomarkers increased after the workday, and the ESTmax means of dehydrated and nondehydrated horses did not differ (P < .05). DIF-CK and DIF-ESTmax were positively correlated (rs = 0.56, P < .05). The cluster analysis defined two groups of horses (LOW and HIGH), with DIF-ESTmax and DIF-CK differing statistically between them. HIGH horses showed CK higher than 350 U/L, indicating some degree of muscle damage. These results suggest that ESTmax has potential to predict changes in CK and, thus could be a useful indicator of physical fitness in ranch horses; although, its effectiveness has to be confirmed in future studies.

Intense exercise and endurance-training program influence serum kinetics of muscle and cardiac biomarkers in dogs.

Few data exist on the physiological consequences of an incremental exercise test (IET) and training in dogs. Here we evaluated the effect of an endurance-training program (ETP) on the kinetics of the serum biomarkers: creatine kinase (CK), aspartate aminotransferase (AST), myoglobin, cardiac troponin I (cTnI), and creatine kinase isoenzyme MB (CK-MB). Eighteen Beagle dogs were assigned to three groups: sedentary (S), untrained (U), and trained (T). The dogs from the groups T and U underwent IET, and their lactate threshold (LT) was determined. The LT and velocity corresponding to the LT (VLT) was determined by visual inspection. The VLT was utilized to determine the training intensity level. Thus, the dogs from group T underwent an eight-week aerobic conditioning program with the intensity training set to 70-80% of the VLT. Next, dogs from the groups T and U have submitted to IET again. The group S did not undergo IETs or training. The maximal velocity (Vmax) at which the dog achieves in the IET and heart rate were determined. For biomarkers, venous blood samples were collected before the experimental procedure (baseline) and before and 1, 6, 12, 24, 48, and 72 h after the IETs. VLT and Vmax increased in group T (P < .05), indicating an improvement in dogs' aerobic and anaerobic fitness. CK and AST rose (P < .05), peaking 6 h after both IETs and returning to baseline levels after 12-24 h. Levels of cTnI and myoglobin were unaltered. CK-MB peaked 1 h after the IETs and returned to baseline levels after 12 h (P < .05). We concluded that ETP improved the aerobic capacity of the dogs without any skeletal or cardiac muscle injury.

Degradation, residual determination, and cholinesterase activity of triclorfon in Piaractus mesopotamicus Holmberg (PACU) 1887.

The aim of this study was to determine the no-observable-adverse-effect concentration (NOAEC) for trichlorfon, an antiparasitic agent used in aquaculture, in Piractus mesopotamicus (pacu) using acetylcholinesterase (AChE) activity as an end point. Fish were exposed 24 h/d for 15 d to different concentrations of trichlorfon in tanks of water for which a curve of dissipation was previously determined. Analysis of trichlorfon in water and fish plasma using gas chromatography with electron capture detection (GC-ECD) enabled measurement of limit of detection (LOD) and limit of quantification (LOQ), respectively, to be 3 and 10 ppb. Thirty-six hours after trichlorfon dilution in water, the concentration was below the LOD, and data showed that plasma concentrations did not exceed the LOQ. Apart from the 6.25 µg/L, all concentrations of trichlorfon significantly inhibited plasma and brain AChE activity compared to controls. The AChE activity levels returned to control values in 7 d. These data may be useful to determine the concentration of trichlorfon that destroys parasites without producing adverse effects in fish.

Ultra-sonografia do músculo longissimus dorsi de eqüinos da raça Puro-sangue Árabe em treinamento de resistência associado à suplementação prolongada com creatina

Objetivou-se padronizar medidas ultra-sonográficas do músculo longissimus dorsi de 12 eqüinos da raça Puro-sangue Árabesubmetidos a treinamento aeróbico por 90 dias, com alimentação suplementada ou não com creatina monoidratada, a fim deverificar se estas mensurações poderiam auxiliar programas de treinamento com animais desta raça, e se a creatina alterariaas medidas ultra-sonográficas. A suplementação consistiu na administração diária de 75g desta substância, misturada àração durante os 90 dias de treinamento. Para determinar as quantidades diárias da ração comercial fornecida, os animaistiveram o peso corpóreo e o escore corporal avaliados mensalmente. O condicionamento físico foi realizado em esteira rolantede alto desempenho e a intensidade do treinamento foi estipulada mediante o cálculo da VLAC 4 (velocidade na qual o lactatosanguíneo atinge 4mmol/L) determinada mensalmente para cada animal. Estabeleceu-se a intensidade do esforço físicoindividual, em 80% do limiar aeróbico. Os animais foram avaliados por meio de exames ultra-sonográficos, mensurando-sea área, largura, profundidade de corte transversal e camada de gordura do músculo longissimus dorsi ao final dos oito mesesde inatividade e após 30, 60 e 90 dias de treinamento. Os resultados da ultra-sonografia revelaram que o treinamento aeróbicoassociado ou não à suplementação com creatina causou hipertrofia do músculo