Distribution of lactate in plasma and erythrocytes during and after exercise in horses (original) (raw)
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Journal of Equine Veterinary Science, 2014
Modifications of some serum electrolyte concentration during two international *** show jumping competition performed in two consecutive weekends were evaluated. Serum sodium (Na), chloride (Cl), magnesium (Mg), potassium (K), phosphorous (P), calcium (Ca), iron (Fe), and blood lactate on 14 well-trained Italian saddle horses were assessed. Blood samples were collected before the beginning of the competition (T0B), within 10 minutes after the end of race (R1, R2, and R3), and on the day after competition (T0R). The same procedure was followed on the second weekend (R4, R5, R6, and T1R). One-way repeated measures analysis of variance was applied on collected data, and a significant effect on sampling time (P < .05) on all parameters studied was found. These results suggest that serum electrolytes and blood lactate concentration are responsive to intense exercise and could be considered an important factor for a correct management training's planning.
Blood lactate concentrations and heart rates of Colombian Paso horses during a field exercise test
Veterinary and Animal Science, 2021
Information on performance indices in Paso horses is scarce. Field exercise tests are necessary to recreate the exertion that occurs during training and competition. To describe blood lactate concentrations and heart rates of untrained Colombian Paso horses (CPHs) in response to a field exercise test. A 30-minutes-long standardized field exercise test was carried out on 11 untrained adult CPHs of both sexes. Blood lactate concentration (BLConc) and heart rate (HR) were measured before, during each step of the test, and at recovery. The BLConc and HR were used to calculate the HR at which a BLConc of 4 mmol/L or anaerobic threshold (HRL 4) was reached. The HR during the field exercise test increased according to the protocol used. The BLConc during the test was variable and, despite having been increasing like the HR, the distribution of the values in each step of the test was remarkably dispersed. The mean blood lactate clearance (BLClear) percentage was 56.3 ± 16, similar in most animals. The HRL 4 was reached at a notably different HR among individuals (132 to 251 bpm). The field exercise test protocol used herein is useful to assess BLConc and HR changes in acute response to exercise in CPHs. It would be useful to evaluate training kinetics with other parameters including cell blood count and muscle enzymes.
Blood lactate threshold reflects glucose responses in horses submitted to incremental exercise test
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2008
The energy necessary for muscle contraction is obtained from the hydrolysis of ATP, releasing inorganic phosphate. ATP can be furnished by phosphocreatine, glucose, glycogen, amino acids and free fatty acids. The production of ATP is much more efficient in the presence of oxygen than in its absence. The anaerobic metabolism of glucose, although less efficient than the aerobic, represents an important and rapid mechanism of energy generation. Several factors regulate the activity of the glycolytic pathway, such as the availability of oxygen, lactate dehydrogenase (LDH) activity and the ATP/ADP ratio. As this ratio decreases the anaerobic glycolysis is stimulated, increasing the production of pyruvate and lactate.
Comparative Clinical Pathology, 2008
Exercise induces changes in hydration and electrolytes status that might affect volumetric properties of erythrocytes. This research analyzes the modifications induced for different type of exercises on volumetric indices in horses in relation to plasma electrolytes, total plasma proteins, heart rate, and lactate. One hundred sixty-four healthy sport horses were studied, divided into six groups: A (16 racing Angloarabians), B (12 jumping Angloarabians), C (45 endurance horses), D (18 Andalusians), E (65 draft horses), and F (eight eventers). In groups A, C, E, and F, blood samples were taken before and after competition. The horses of groups B and D were subjected to an exercise test and blood samples were taken before and after the test. The parameters analyzed were: packed cell volume (PCV), mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), Na, K, Cl, heart rate, total plasma proteins, and plasma lactate concentrations. PCV increased in all the groups, MCV decreased in group D, MCH increased in groups D and F and decreased in group E, and MCHC increased with exercise in groups A and F. The only significant correlation between plasma electrolyte and volumetric indices was found between plasma Na concentrations and MCV. It is concluded that, although volumetric indices change with exercise in horses, their modifications are somewhat erratic and do not show a direct correlation with hydration, electrolyte status and exercise intensity, but red blood cell size is partially dependent on plasma Na concentration.
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2007
Maximal blood lactate steady state concentration (MLSS) and anaerobic threshold (AT) have been shown to accurately predict long distance events performance and training loads, as well, in human athletes. Horse endurance races can take up to 160 km and, in practice, coaches use the 4 mM blood lactate concentration, a human based fixed concentration to establish AT, to predict training loads to horse athletes, what can lead to misleading training loads. The lactate minimum speed (LMS) protocol that consists in an initial elevation in blood lactate level by a high intensity bout of exercise and then establishes an individual equilibrium between lactate production and catabolism during progressive submaximal efforts, has been proposed as a nonfixed lactate concentration, to measure individual AT and at the same time predicts MLSS for human long distance runners and basketball players as well. The purpose of this study was to determine the reliability of the LMS protocol in endurance horse athletes. Five male horses that were engaged on endurance training, for at least 1 year of regular training and competition, were used in this study. Animals were submitted to a 500 m full gallop to determine each blood lactate time to peak (LP) after these determinations, animals were submitted to a progressive 1000 m exercise, starting at 15 km h − 1 to determine LMS, and after LMS determination animals were also submitted to two 10,000 m running, first at LMS and then 10% above LMS to test MLSS accuracy. Mean LP was 8.2 ± 0.7 mM at approximately 5.8 ± 6.09 min, mean LMS was 20.75 ± 2.06 km h − 1 and mean heart rate at LMS was 124.8 ± 4.7 BPM. Blood lactate remained at rest baseline levels during 10,000 m trial at LMS, but reached a six fold significantly raise during 10% above LMS trial after 4000 and 6000 m (p < 0.05) and (p < 0.01) after 8000 and 10,000 m. In conclusion, our adapted LMS protocol for horse athletes proposed here seems to be a reliable method to state endurance horse athletes LT and MLSS.
Effect of differences in post-exercise lactate accumulation in athletes’ haemodynamics
Applied Physiology, Nutrition, and Metabolism, 2006
To verify the relationship between exercise intensity and post-exercise haemodynamics, we studied haemodynamic and lactate responses during 10 min following 3 bicycle tests. Two tests were performed for 3 min at 70% and 130% of the workload corresponding to anaerobic threshold (70% Wat and 130% Wat tests), and 1 was performed until exhaustion at 150% of the maximum workload achieved during a previous incremental test (150% Wmax test). During the recovery period after the 150% Wmax test we observed the highest increases in blood lactate with respect to the baseline: at the 9th minute of recovery lactate concentration increased by +9.3 ± 2.7, +6.4 ± 3.1, and +1.1 ± 0.9 mmol·L–1 in the 150% Wmax (p > 0.05 with respect to the other protocol sessions), 130% Wat, and 70% Wat tests, respectively. We also observed greater reductions in cardiac pre-load and systemic vascular resistance in the 150% Wmax test than in the 130% Wat and 70% Wat tests. However, the cardiac output response succe...
Lactate-transport activity in RBCs of trained and untrained individuals from four racing species
American journal of physiology. Regulatory, integrative and comparative physiology, 2001
In red blood cells (RBC) of horses, both lactate-transport activity and lactate accumulation during races vary interindividually. To study whether similar variation in lactate transport is apparent also in RBCs of other racing species, blood samples were collected from 21 reindeer, 40 horses, 31 humans, and 38 dogs. Total lactate-transport activity was measured at 10 and 30 mM concentrations, and the roles of the monocarboxylate-transporter (MCT) and the inorganic anion-exchange transporter (band-3 protein) were studied with inhibitors. In the reindeer and in one-third of the horses, lactate transport was low and mediated mainly by band-3 protein and nonionic diffusion. In the humans, dogs, and the remaining two-thirds of the horses, lactate transport was high and MCT was the main transporter. No correlation existed between MCT activity and the athleticism of the species. In the horses and humans, training had no effect on lactate transport, but in the reindeer and sled dogs, traini...
Journal of Sports Sciences, 1992
This paper reports the findings of two investigations into methodological problems associated with the interpretation of blood lactate (BLa) in the sports sciences. In Experiment 1, brachial artery (A), antecubital venous (V) and fingertip capillary (C) blood samples were drawn simultaneously from nine subjects (mean age 21.1 ± 1.3 years) during an incremental treadmill protocol and immediately assayed for BLa concentration. Experiment 2 investigated the extent of lactate concentration differences in whole blood (WB), lysed blood (LB) and plasma (P) measured using a YSI 23 AM analyser. In Experiment 1, a comparison of the mean BLa concentrations obtained from the three sites revealed no significant differences (P> 0.05). Correlations between BLa samples from different sites were very high, with r values ranging from 0.858 to 0.983. In Experiment 2, the mean lactate concentrations were: WB, 4.7 + 2.7 mM; LB, 5.0 + 3.0 mM; P, 7.0 + 3.8 mM. Plasma (P) values were significantly higher than WB and LB. Values from all sites were highly correlated with coefficients ranging from 0.963 to 0.987. In conclusion: (1) Significant arterial and venous BLa concentration differences do not exist during incremental treadmill exercise. (2) As capillary BLa concentrations reflect arterial values, their use in laboratory and field settings is recommended. (3) Lactate concentration differences in whole blood, lysed blood and plasma will influence the assessment of performance at fixed lactate reference values.
Low dose of dichloroacetate infusion reduces blood lactate after submaximal exercise in horses
Pesquisa Veterinária Brasileira, 2013
Pesq. Vet. Bras. 33(1):57-60, janeiro 2013 57 RESUMO.-[Baixa dose de infusão de dicloroacetato reduz o lactato sanguíneo após exercício submáximo em cavalos.] A administração aguda de um ativador indireto da enzima piruvato desidrogenase (PD) em atletas da espécie humana provoca redução na concentração de lactato sanguíneo durante e após exercício. Uma dose única, intravenosa de 2.5m.kg -1 de dicloroacetato (DCA) foi administrada antes de um exercício teste incremental submáximo . 2013. Low dose of dichloroacetate infusion reduces blood lactate after submaximal exercise in horses. Pesquisa Veterinária Brasileira 33 :57-60. The acute administration of an indirect activator of the enzyme pyruvate dehydrogenase (PDH) in human athletes causes a reduction in blood lactate level during and after exercise. A single IV dose (2.5m.kg -1 ) of dichloroacetate (DCA) was administered before a submaximal incremental exercise test (IET) with five velocity steps, from 5.0 m.s -1 for 1 min to 6.0, 6.5, 7.0 and 7.5m.s -1 every 30s in four untrained mares. The blood collections were done in the period after exercise, at times 1, 3, 5, 10, 15 and 20 min. Blood lactate and glucose (mM) were determined electro-enzymatically utilizing a YSI 2300 automated analyzer. There was a 15.3% decrease in mean total blood lactate determined from the values obtained at all assessment times in both trials after the exercise. There was a decrease in blood lactate 1, 3, 5, 10, 15 and 20 min after exercise for the mares that received prior DCA treatment, with respective mean values of 6.31±0.90 vs 5.81±0.50, 6.45±1.19 vs 5.58±1.06, 6.07±1.56 vs 5.26±1.12, 4.88±1.61 vs 3.95±1.00, 3.66±1.41 vs 2.86±0.75 and 2.75±0.51 vs 2.04±0.30. There was no difference in glucose concentrations. By means of linear regression analysis, V 140 , V 160 , V 180 and V 200 were determined (velocity at which the rate heart is 140, 160, 180, and 200 beats/minute, respectively). The velocities related to heart rate did not differ, indicating that there was no ergogenic effect, but prior administration of a relatively low dose of DCA in mares reduced lactatemia after an IET.