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1.
Exercise represents a physical stress that challenges homeostasis affecting central and peripheral serotoninergic systems. The influence of the exercise on circulating serotonin (5-hydroxytryptamine [5-HT]) levels depends on training state as well as the exercise protocol. The purpose of the present research was to determine changes of plasma 5-HT in sport horses in response to training (T) and simulated race (SR) and in addition to assess the possible presence of significant differences on circulating 5-HT between two different sessions of exercise. In particular, the research was carried out on 18 trained horses performing daily training and race activity. Plasma 5-HT levels were analyzed in platelet poor plasma fraction by ELISA assay at T0 (before exercise), T1 (30 minutes after exercise) and T2 (2 hours after exercise). The hypothesis was that both exercise sessions could affect plasma 5-HT levels. Results showed a significant increase of plasma 5-HT levels at T1, compared with T0, both after simulated race and training activity. These effects are probably related to an increased 5-HT release from platelets and/or an increased peripheral 5-HT synthesis induced from exercise. At T2, plasma 5-HT concentrations showed a significant decrease to physiological levels in both sessions. Moreover, plasma 5-HT levels at T1 (SR) were significantly higher than those at T1 (T). Targeting peripheral 5-HT could be useful to assess the physiological adaptability of horses to the exercise, together with other selection techniques of sport horses.  相似文献   

2.
Serotonin (5-hydroxytryptamine, 5-HT) signalling is implicated in the pathogenesis of myxomatous mitral valve disease (MMVD) through 5-HT1B receptor (R), 5-HT2AR and 5-HT2BR-induced myxomatous pathology. Based on increased tryptophan hydroxylase-1 (TPH-1) and decreased serotonin re-uptake transporter (SERT) in MMVD-affected valves, increased valvular 5-HT synthesis and decreased clearance have been suggested. It remains unknown how haemodynamic changes associated with mitral regurgitation (MR) affect 5-HT markers in the mitral valve, myocardium and circulation. Twenty-eight pigs underwent surgically induced MR or sham-operation, resulting in three MR groups: control (CON, n = 12), mild MR (mMR, n = 10) and severe MR (sMR, n = 6). The gene expression levels of 5-HT1BR, 5-HT2AR, 5-HT2BR, SERT and TPH-1 were analysed using quantitative PCR (qPCR) in the mitral valve (MV), anterior papillary muscle (AP) and left ventricle (LV). MV 5-HT2BR was also analysed with immunohistochemistry (IHC) in relation to histological lesions and valvular myofibroblasts. All 5-HTR mRNAs were up-regulated in MV compared to AP and LV (P <0.01). In contrast, SERT and TPH-1 were up-regulated in AP and LV compared to MV (P <0.05). In MV, mRNA levels were increased for 5-HT2BR (P = 0.02) and decreased for SERT (P = 0.03) in sMR vs. CON. There were no group differences in 5-HT2BR staining (IHC) but co-localisation was found with α-SMA-positive cells in 91% of all valves and with 33% of histological lesions. In LV, 5-HT1BR mRNA levels were increased in sMR vs. CON (P = 0.01). In conclusion, these data suggest that MR may affect mRNA expression of valvular 5-HT2BR and SERT, and left ventricular 5-HT1BR in some pigs.  相似文献   

3.
In the present study, we investigated the regulatory mechanisms underlying sperm hyperactivation enhanced by 5-hydroxytryptamine (5-HT) in hamsters. First, we examined the types of 5-HT receptors that regulate hyperactivation. Hyperactivation was significantly enhanced by 5-HT2A and 5-HT4 receptor agonists. Moreover, the results of the motility assay revealed that 5-HT2A, 5-HT3, and 5-HT4 receptor agonists significantly decreased the velocity and/or amplitude of sperm. Under 5-HT2 receptor stimulation, hyperactivation was associated with phospholipase C (PLC), inositol 1,4,5-trisphosphate (IP3) receptor, soluble adenylate cyclase (sAC), and protein kinase A (PKA). In contrast, under 5-HT4 receptor stimulation, hyperactivation was associated with transmembrane adenylate cyclase (tmAC), sAC, PKA, and CatSper channels. Accordingly, under the condition that sperm are hyperactivated, 5-HT likely stimulates PLC/IP3 receptor signals via the 5-HT2A receptor and tmAC/PKA/CatSper channel signals via the 5-HT4 receptor. After sAC and PKA are activated by these stimulations, sperm hyperactivation is enhanced.  相似文献   

4.
In horses, gastrointestinal (GI) disorders occur frequently and cause a considerable demand for efficient medication. 5-Hydroxytryptamine receptors (5-HT) have been reported to be involved in GI tract motility and thus, are potential targets for treating functional bowel disorders. Our studies extend current knowledge on the 5-HT7 receptor in equine duodenum, ileum and pelvic flexure by studying its expression throughout the intestine and its role in modulating contractility in vitro by immunofluorescence and organ bath experiments, respectively.5-HT7 immunoreactivity was demonstrated in both smooth muscle layers, particularly in the circular one, and within the myenteric plexus. Interstitial cells of Cajal (ICC), identified by c-Kit labeling, show a staining pattern similar to that of 5-HT7 immunoreactivity.The selective 5-HT7 receptor antagonist SB-269970 increased the amplitude of contractions in spontaneous contracting specimens of the ileum and in electrical field-stimulated specimens of the pelvic flexure concentration-dependently.Our in vitro experiments suggest an involvement of the 5-HT7 receptor subtype in contractility of equine intestine. While the 5-HT7 receptor has been established to be constitutively active and inhibits smooth muscle contractility, our experiments demonstrate an increase in contractility by the 5-HT7 receptor ligand SB-269970, suggesting it exerting inverse agonist properties.  相似文献   

5.
The vasomotor effects of 5-hydroxytryptamine (5-HT) on isolated equine basilar arteries were studied. 5-HT induced contractions of equine basilar arteries in a concentration-dependent manner, with a pEC50 value (with 95% confidence limits) of 7.35 (7.08–7.62). Similar results were obtained with endothelium-denuded basilar arteries. Contractions were not competitively inhibited by the 5-HT2 receptor antagonist ketanserin at low concentrations of 5-HT. Conversely, at high concentrations of 5-HT, contractions were inhibited by ketanserin in a concentration-dependent manner, with a pA 2 value of 8.91 (8.62–9.20). The 5-HT1 and 5-HT2 receptor antagonist methiothepin shifted the concentration-response curve of 5-HT downwards and to the right in a concentration-dependent manner. In the presence of 10-6 mol/L ketanserin, however, methiothepin antagonized 5-HT-induced contractions competitively with a pA 2 value of 7.95 (7.59–8.31). The 5-HT3 receptor antagonist MDL 72222 had no effect on 5-HT-induced contractions. The findings of this study indicate that 5-HT1 and 5-HT2 receptors are located in equine basilar arterial smooth muscle cells, and that stimulation of these receptors results in contraction.Abbreviations CR concentration ratio - EC50 concentration producing 50% of the maximal response - 5-HT 5-hydroxytryptamine - MDL 72222 1H,3,5H-tropan-3-yl-3,5-dichlorobenzoate - pA 2 negative logarithm of the molar concentration of antagonist that produces a 2-fold rightward shift of the concentration-response curve - pEC50 negative logarithm of EC50 - PGF2 prostaglandin F2  相似文献   

6.
Serotonin (5-HT) is a neurotransmitter implicated in the regulation of circadian rhythms. Synthesis and release of 5-HT are subjected to daily fluctuations, but there are no data on plasma serotonin levels in 2-year-old horses. Aim of this study was to investigate the daily variations in 5-HT levels in platelet-poor plasma from 2-year-old horses, so as to understand whether plasma 5-HT could be considered as an additional variable to assess the natural adaptability of horses to training. The research was carried out on 6 clinically healthy crossbred mares. Data showed higher levels of platelet-poor plasma 5-HT at 5 p.m. (P < 0.001) than at 1 p.m. and lower values at 5 a.m. (P < 0.001) than at 1 a.m. One-way repeated-measures analysis of variance showed a significant effect of sampling time (P < 0.0001) on plasma 5-HT changes. Results suggest that the increase of 5-HT levels could be related to an enhanced 5-HT output and release, and that their daily variations could be considered as an additional variable to assess the natural adaptability of horses for being trained. Tryptophan levels, the essential amino acid precursor of 5-HT, seemed to hint at slight fluctuations at regular intervals, with the highest amounts at 9 a.m. and at 9 p.m. and lowest at 1 a.m. and at 1 p.m., in agreement with data reported in adult horses. Cortisol levels showed wide fluctuations, with the highest amounts at 1 a.m. and the lowest amounts at 9.00 p.m.  相似文献   

7.
The effects of peripheral (intravenous, i.v.) and central (intracerebroventricular, ICV) administrations of agonists of 5-HT1A, 5-HT2, 5-HT3 and 5-HT4 receptors were investigated in conscious sheep chronically fitted with intraparietal electrodes on the reticulum and the dorsal, ventral and caudo-ventral rumen. The 5-HT1A agonist 8-hydroxydipropylaminotetralin increased reticular and decreased ruminal spike burst frequency when given i.v. (80 μg/kg) and ICV (8 μg/kg). The 5-HT2 and 5-HT3 agonists, α-methylserotonin and 2-methylserotonin, induced a moderate inhibition of rumino-reticular contractions when given i.v. at 100 and 150 μg/kg, respectively, while marked inhibition was observed after ICV administration at doses of 10 and 5 μg/kg, respectively. The 5-HT4 agonist 5-methoxytryptamine strongly stimulated rumino-reticular motility by the ICV (10 μg/kg) route, whereas it induced a moderate inhibition when administered i.v. (200 μg/kg). The selective antagonist of 5-HT1A, 5-HT2, 5-HT3 and 5-HT4 receptors, spiroxatrine, ritanserin, granisetron and DAU 6285, respectively, blocked the responses of the respective agonists given by the same route. Moreover, the antagonists given ICV blocked the effects of the agonists given i.v. except for DAU 6285 ICV, which did not antagonize the inhibition induced by 5-methoxytryptamine i.v. It is concluded that the four types of serotonergic receptors investigated control rumino-reticular motility at the central level. However, according to the receptor type and the forestomach area (reticulum or rumen) this control may be stimulatory or inhibitory, demonstrating a pleiotropic role of serotonin in the control of rumino-reticular motility in sheep.  相似文献   

8.
The purpose of this study was to evaluate the influence of exercise on plasma tryptophan (TRP) and free serotonin (f5-HT), whole blood-5-HT (WB-5-HT) and f5-HT/WB-5-HT ratio in Italian Saddle horses. Six clinically healthy Italian Saddle horses were subjected to a 450 meters obstacles course. Blood samples were collected from each horse by jugular venipuncture using vacutainer tubes with K3-EDTA at rest, immediately after exercise, and after 30 min. TRP, f5-HT and WB-5-HT were analyzed by HPLC. Immediately after exercise, statistically significant increases of f5-HT (p<0.001) and WB-5-HT (p<0.001) were observed. After 30 min, f5-HT and WB-5-HT decreased compared to immediately after exercise, but were still significantly higher than rest values (p<0.01 and p<0.05, respectively). A significant linear regression between f5-HT and WB-5-HT was observed during experimental conditions. f5-HT and WB-5-HT modifications after exercise suggest an important role of peripheral serotoninergic markers in response to physical activity. The possible source of extra serotonin detected after show jumping should be clarified by further investigation.  相似文献   

9.
Eight mature (12 +/- 2 yr; MAT) and 5 older (22 +/- 2 yr; OLD) Standardbred mares were used to test the hypothesis that aging and exercise training would alter apoptosis in white blood cells and antioxidant status. The horses were housed indoors overnight (16 h/d) in 3 m x 3 m stalls and were turned out in a drylot during the day. They were fed a diet consisting of total mixed ration, hay cubes fed ad libitum or an equine senior diet plus grass hay. Horses were trained for 20 to 30 min/d, 3 to 5 d/wk for 8 wk at a submaximal work intensity between 60 to 70% of maximal heart rate. A graded exercise test (GXT; stepwise test until exhaustion) was performed before (GXT1) and after (GXT2) the 8 wk of training. During the GXT, blood samples and heart rate were taken at rest, 6 m/s, fatigue, and at 5 and 60 min postfatigue. Fatigue plasma lactate concentration was greater in MAT (19.3 +/- 1.5 at 10 m/s) compared with the OLD (10.9 +/- 1.2 mmol/L at 9 m/s; P = 0.008) horses. There was no effect of age or training on plasma lipid hydroperoxide (LPO) concentration. However, there was a positive correlation between LPO and plasma lactate concentration (r = 0.27, P = 0.006) during acute exercise. There was a greater concentration of total glutathione after GXT1 than after GXT2 (111.8 +/- 5.0 vs. 98.6 +/- 3.4 microM, respectively; P = 0.0002) for both age groups. Apoptosis was less (P = 0.002) in white blood cells of the MAT vs. the OLD group. These results demonstrate that older horses are under similar amounts of oxidative stress, measured by LPO, and have similar levels of glutathione in their systems compared with mature horses. The observation that more glutathione was needed during GXT1 for both groups of horses indicates that training helps horses adapt their system for the intense post-training exercise tests. The greater level of white blood cell apoptosis also indicates that older horses may be immune-compromised during exercise. However, research still needs to be performed regarding dietary supplementation in the aged horse.  相似文献   

10.
The aim of this study was to investigate the responses to exercise in athletic horses fed different protein levels. Twenty-four Brazilian Sport Horses (body weight [BW] between 432 and 560 kg and body condition score [BCS] 5.0–5.5) undergoing eventing training were used. The experiment was a randomized design with four treatments (diets) and two exercise tests. Diets were composed of 7.5%, 9.0%, 11.0%, and 13.0% crude protein. The exercise tests consisted of a warm-up and galloping from 6.0 m/s with speed increases every 1 minute until 10 m/s. Venous blood samples were collected at preprandial time, before, during, and after the exercise tests, and at the recovery time. Blood samples were analyzed for hematocrit, lactate, glucose, total plasma protein, serum aspartate aminotransferase, creatine kinase, lactate dehydrogenase, urea, uric acid, creatinine, serum Cl−, and venous blood gas. The results were analyzed using a split-plot design, and regression analyses were performed. There were no differences in BW and BCS. The protein levels did not affect the variables VL2, VL4, V150, and V200. Serum urea and uric acid concentrations were affected by protein diet levels. After the exercise tests, the blood pH, acid–base, and electrolyte balance of the horses were not affected by the protein of the diets. The protein diet levels did not affect the horses' performance variables. At the same time, high protein concentrations in the diet can alter the acid–base balance in athletic horses and should be used with caution.  相似文献   

11.
Physiological and hematochemical changes associated with exercise have been extensively investigated in equine species. It is known that stress elevates circulating levels of acute phase proteins (APPs). This survey evaluated whether horses trained with different training programs exhibit changes in APP levels after exercise event. Twenty Saddle Italian horses (11 geldings and 9 females, 9 ± 1 years old, body weight of 425 ± 35 kg) were divided into two equal groups according to the intensity of training programs they were subjected: group A was subjected to an intense training program, group B was subjected to a moderate training program. At the end of the training period, horses were subjected to a simulated exercise event (show jumping course of 400 m length with 12 obstacles). From horses, blood samples were collected at rest conditions (TREST) and after 12 and 24 hour from the end of exercise (T12 h and T24 h); the concentration of serum amyloid A (SAA), haptoglobin, albumin, total proteins, iron, and fibrinogen was assessed. The circulating levels of SAA, fibrinogen, and iron were influenced by simulated exercise event (P < .01), starting from 12 hour after the end of exercise, suggesting the onset of an acute phase–like response, and it would seem that training program intensity the horses underwent also affected the degree of response, although only SAA values were significantly different between groups (P < .001). The findings obtained suggest that jumping exercise induces an acute phase response; however, further studies are advocated to better evaluate mechanisms by which exercise activates this response in the athletic horse.  相似文献   

12.
Reliable physiological markers for performance evaluation in sport horses are missing. To determine the diagnostic value of plasma ACTH and cortisol measurements in the warmblood horse, 10 initially 3-yr-old geldings of the Hannovarian breed were either exposed to a training schedule or served as controls. During experimental Phase 1, horses were group-housed, and half of the horses were trained for 20 wk on a high-speed treadmill. During Phase 2, groups were switched and one group was trained for 10 wk as during Phase 1, whereas the control group was confined to boxes. During Phase 3 horses were initially schooled for riding. Thereafter, all horses were regularly schooled for dressage and jumping, and half of the horses received an additional endurance training for 24 wk. During all phases horses were exposed at regular intervals to various standardized treadmill exercise tests. During and after the tests frequent blood samples were taken from an indwelling jugular catheter for determination of ACTH and cortisol. Treadmill exercise increased both hormones. Maximum ACTH concentrations were recorded at the end of exercise, and maximum cortisol levels were recorded 20 to 30 min later. Except for one test there were no differences in ACTH levels between trained horses and controls. There was no significant effect of training on the cortisol response (net increase) to treadmill exercise in any of the tests during Phase 1. During Phase 2 higher cortisol responses were recorded in controls than in trained horses (P < .05) after 10 wk of training (controls confined to boxes). During Phase 3 plasma cortisol responses were also higher in controls than in trained horses (P < .05 after 6, 18, and 24, P < or = .07 after 12 wk of training) when the inclination of the treadmill was 5%, but not at 3%. There was no overlap in net cortisol responses at 30 min between trained and untrained horses. An ACTH application after 24 wk of training resulted in higher cortisol responses in controls than in trained horses (P < or = .05), without any overlap between the groups at 30 min after ACTH. Plasma cortisol responses to either treadmill exercise or ACTH injection may be a reliable physiological marker for performance evaluation. Prerequisites are sufficient differences in training status and sufficient intensity of exercise test conditions.  相似文献   

13.
Several indices of ventilatory heterogeneity can be identified from the volumetric capnogram and its graphic presentation, the single-breath diagram for CO2 (SBD-CO2). Physiologically based indices of pulmonary function (VTE, VCO2, F ACO2, VDBohr, VDBohr%, VD/VTE, A 1/A 2) were calculated for healthy horses (group I, n = 5) and for horses with subclinical (group II, n = 7) or clinically manifest chronic obstructive pulmonary disease (COPD) (group III, n = 8) during tidal breathing and after medication with lobelin hydrochloride (Lobelin). We investigated the variability and repeatability of the lung function indices in healthy horses and in those with COPD both during tidal breathing and after administration of Lobelin, a centrally acting respiratory stimulant. In particular, we were interested in whether the discriminating ability of SBD-CO2-derived lung function indices would be increased between different patient groups after administration of Lobelin compared to those for the resting values. Of the indices studied, VTE, F ACO2, VDBohr% and A 1/A 2 appeared to be those with good to excellent repeatability in discriminating healthy horses from those with COPD. Stimulating respiration with Lobelin gave no advantage in the repeatability of the lung function indices or in differentiating between horses with different degrees of COPD.  相似文献   

14.
The effect of recovery from training has not been studied in horses. Therefore, the effect of recovery was examined with exercise of known effect within a conditioning period (CP). A standardized exercise test was performed at the beginning of CP to determine v4, v10, and v180 (horse’s speed, which produced a blood lactate concentration of 4 and 10 mmol/L and a heart rate of 180 beats/min). Six horses were conditioned for three periods of 2 weeks, 5 times per fortnight at their individual v10 for two bouts of 5 minutes on a treadmill. Every 2 weeks of conditioning was followed by 1 week with reduced workload. Standardized exercise test was repeated after each 2 weeks of conditioning and 2 weeks after finishing CP. Exercise speed was individually adapted to the new v10 for every 2 weeks of conditioning. In addition, peak oxygen consumption before, after 3 weeks of conditioning, and at the end of the CP was measured. The mean v4 increased steadily during CP. v180 did not change, whereas peak oxygen consumption increased between the beginning and after 3 weeks of conditioning and leveled off thereafter. In conclusion, reducing the workload for 1 week after 2 weeks of conditioning 5 times per fortnight at v10 for two bouts of 5 minutes allowed for a continuous increase of v4, but the extent of the increase was smaller than in another study with a similar conditioning program but for the recovery week. The effect of recovery from training needs further studies.  相似文献   

15.
Athletic performance is both a stress factor and an adaptive response to exercise that may be modulated by training, reduce inflammation and help prevent disease. Studies on the endocrinology of exercise and training have demonstrated the existence of an integrated metabolic network of hormone and cytokine regulation. Subsequent molecular studies have shown that repeated bouts of exercise may establish new basal levels of gene expression at rest.The Thoroughbred horse may be a useful ‘exercise model’ for inter-individual comparisons between subjects with homogeneous genetic and environmental backgrounds and similar exercise management practices. In this study, the effects of training and acute effort on gene expression were evaluated with a real time PCR approach in athletic (n = 10) and sedentary horses (n = 9), using a previously characterised panel of genes known to be highly modulated during effort (CXCL2, TLR4, IL1β, IL8, IL1RII, IL18, IL6 and CEBPβ). A ‘rest comparison’ was performed to evaluate a training effect in both groups while a ‘race comparison’ was performed in athletic horses only (before, immediately after, and 12 h after racing) to determine the effect of acute effort.The results indicated that many of the investigated genes (TLR4, IL1β, IL1RII, IL18, IL6 and CEBPβ) were expressed to a greater extent in athletic horses compared to sedentary animals when both were at rest. However, a time-course comparison in the athletic horses revealed that genes exhibiting the highest levels of expression at rest did not show significant changes after the race. The findings suggested that training may exert a conditioning on gene expression at rest leading to a more prompt response to exercise-induced stress in Thoroughbreds.  相似文献   

16.
REASONS FOR PERFORMING STUDY: Increased plasma (5-HT) concentrations are reported in horses predisposed to develop laminitis and after i.v. infusion of endotoxins. In the equine jejunum contractile 5-HT1A-like receptors show tachyphylaxia upon prolonged activation with 5-HT. Therefore, increased systemic 5-HT release in colic horses could play a possible role in the pathophysiology of ileus. OBJECTIVE: To investigate possible increased systemic release of 5-HT in colic horses with compromised bowel and to identify the source of 5-HT overload. METHODS: Concentrations of 5-HT were determined in plasma and peritoneal fluid (PF) of healthy horses (n = 10), strangulating small intestinal colic horses (n = 18), nonsurgical colic horses (n = 10) and cryptorchid stallions (n = 6). It was attempted to identify the source of 5-HT overload by comparing the blood and PF 5-HT concentrations within horses and by assessing the in vivo platelet activation through determination of the beta-thromboglobulin (beta-TG)/platelet factor 4 (PF4) ratio. RESULTS: All horses in the strangulating small intestinal colic group had plasma (P = 0.006) and PF (P = 0.01) 5-HT concentrations above those found in the control group. Plasma beta-TG/PF4 ratio in these horses exceeded 2 in all cases, indicating in vivo platelet activation. Concentrations of 5-HT in PF of colic horses with compromised bowel were significantly lower than the corresponding plasma concentrations (P = 0.005). Potential relevance: In horses with compromised bowel, significant amounts of 5-HT can be released into the systemic circulation, through massive release of platelet-stored 5-HT. 5-HT is a very potent proinflammatory, vasoconstrictive and immunomodulatory agent. In view of the rapid and prolonged tachyphylaxia, shown for the jejunal 5-HT1A-like receptors, this increased systemic 5-HT release could play a role in the pathophysiology of ileus in horses.  相似文献   

17.
Physical activity and stress both cause an increase in cortisol release ratio. The aim of this study was to evaluate the use of saliva samples for the determination of cortisol concentrations indicating the work‐load level in horses during race training. Twelve Purebred Arabian horses aged 3–5 years were studied during the routine training session. After the warm‐up, the horses galloped on the 800 m sand track at a speed of 12.8 m/s. Three saliva samples, and three blood samples were collected from each horse. Both types of samples were taken at rest, immediately after return from the track and after 30 min restitution. The concentrations of blood lactic acid (LA), and cortisol in saliva and plasma samples were measured and analyzed. Blood LA, plasma and salivary cortisol levels increased significantly after exercise (P < 0.05). Salivary cortisol concentration determined 30 min after the exercise correlated significantly with plasma cortisol level obtained immediately after exercise (P < 0.05) as well as measured 30 min after the end of exercise (P < 0.05). The determination of cortisol concentration in saliva samples taken from racehorses 30 min after the end of exercise can be recommended to use in field conditions to estimate the work‐load in racehorses.  相似文献   

18.
The discriminating ability of 15 parameters alone or in combinations, including results from analysis of plasma endotoxin, the Nycomed plasma D-Dimer test and phospholipase A2, were analyzed to predict morbidity and mortality in equine gastrointestinal colic. Endotoxaemia was a characteristic feature of the colic horses. The problem of adequately predicting non-survivors among colic horses required several parameters to be included in the logistic model: if the “classical parameters”, (heart rate, respiratory rate, PCV, anion gap) were included in the model, addition of plasma D-dimer, phospholipase A2, and Cl- significantly improved the predictive value of the logistic model. Increasing heart rate and D-dimer together with decreasing chloride was a risk factor for nonsurvival. The sensitivity of this three-parameter logistic model to predict nonsurvival was 78% and specificity 77%. The Nycomed D-Dimer test is recommended as a horse-site test to predict disseminated intravascular coagulation and nonsurvival in equine colic.  相似文献   

19.
Horse trekking is a noncompetitive physical activity conducted as a recreation and leisure experience, but so far potential effects on physiological changes in horses have not been investigated. The aim of the present research was to study whether trekking would affect plasma serotonin (5-hydroxytryptamine [5-HT]) concentrations in platelet poor plasma samples, together with its precursor tryptophan, and other hematological and functional variables. The study was carried out on 28 clinically healthy horses, habitually used for trekking, of which 18 participated in a 2-day trekking event, and 10 were used as the control group. The results obtained showed a significant effect of exercise on the serotonin, red blood cell, white blood cell, platelet, hematocrit, hemoglobin, heart rate, respiratory rate, and rectal temperature changes. These effects are probably related to a combination of submaximal exercise and some degree of dehydration. Prolonged and aerobic exercise, like that involved in trekking, could affect both the release of 5-HT from the stores in the blood stream as well as hematological and functional adaptations in response to physical effort. Moreover, results confirm a physiological influence of 5-HT in the regulation of the vascular system, induced by exercise. The present findings imply that assessment of plasma 5-HT as well as hematological and functional variables may be proposed as an additional tool to evaluate the physiological adjustment in response to physical activity in trained horses that may influence their performance.  相似文献   

20.
Both physical activity and stress result in an increase in plasma cortisol level. The measurement of cortisol in plasma requires taking blood samples, which is stressful itself. Therefore, the aim of this study was to evaluate the use of saliva sampling for the determination of cortisol concentrations, indicating the intensity of exercise in horses during race training. Twelve Thoroughbred horses aged 2-3 years were examined during their speed training sessions. The horses galloped on the 1,200-m sand track at a speed of 14.4-15.3 m/s. Three saliva samples and three blood samples were collected from each horse. Both types of samples were taken when the horse was at rest, immediately after returning from the track and 30 minutes after the end of exercise. Blood lactic acid (LA) concentration was determined using the enzymatic cuvette test. The concentrations of cortisol in saliva and plasma samples were measured by enzyme immunoassay methods. Statistically significant correlations were found between salivary cortisol level determined 30 minutes after the end of exercise and blood LA concentration obtained immediately after exercise (P = .003) and between salivary and plasma cortisol levels measured 30 minutes after the end of training session (P = .015). The measurement of cortisol concentration in saliva samples taken from race horses 30 minutes after the end of exercise can be recommended for use in practice under field conditions to estimate the level of relative intensity of exercise in race horses.  相似文献   

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