首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 62 毫秒
1.
In Study 1, a single speed test of 6 to 12 m/sec was performed for 2 mins at an incline of 5 degrees on a high-speed treadmill (single-step test). Only one speed was performed per session and blood samples were taken before and after the test. In Study 2 horses cantered for 1 min at increasing speeds of 6 to 13 m/sec on an incline of 3 degrees (multiple-step test). Blood samples were taken before exercise, throughout the test and during recovery. In the single-step test plasma concentrations of adrenaline and noradrenaline both increased at speeds of 9 m/sec, as did blood lactate. Mean concentrations of adrenaline and noradrenaline at the end of the 12 m/sec test were 153 and 148 nmol/litre, respectively. Plasma concentrations were similar over all speeds although there was a tendency for the increase in noradrenaline to be greater than that of adrenaline at the lower speeds. The multiple-step test resulted in smaller increases in both adrenaline and noradrenaline. Although again closely correlated, increases in adrenaline were 20-30% greater than those for noradrenaline. In both exercise models, changes in plasma adrenaline and noradrenaline values with exercise showed an exponential relationship to plasma lactate. A plasma half-life of less than 30 secs was indicated during recovery from the multiple-step test. Changes in adrenaline and noradrenaline were much greater than previously recorded in man and emphasise the importance of catecholamines in mediating the physiological response of the horse to exercise.  相似文献   

2.
AIM: To compare the changes in plasma concentrations of noradrenaline, adrenaline and cortisol in lambs after ring castration plus tailing and in calves after dehorning with or without prior local anaesthesia. METHODS: Male lambs were castrated and tailed with rings and calves were dehorned by amputation using a scoop with or without prior local anaesthesia. Blood samples were taken before and after treatment and plasma concentrations of noradrenaline, adrenaline and cortisol were determined. RESULTS: Castration plus tailing of lambs resulted in a rapid increase in noradrenaline concentrations, a lack of an adrenaline response and a marked increase in cortisol concentration. There were similar changes in catecholamine concentrations in calves that were dehorned both with and without local anaesthetic, with adrenaline being elevated within 5 min of treatment and noradrenaline exhibiting a more protracted response. Dehorning caused a marked cortisol increase which was reduced to control concentrations by local anaesthesia for as long as the associated nerve blockade lasted. CONCLUSIONS: The very short-lived adrenaline responses in calves were attributed to dehorning-induced nociceptor input leading to sympathetic stimulation of the adrenal medulla. The longer lasting noradrenaline responses in lambs and calves were thought be due to 'wash-out' of noradrenaline from damaged tissue associated with rings and amputation wounds, respectively.  相似文献   

3.
To determine the effects of exercise, high heat and humidity and acclimation on plasma adrenaline, noradrenaline, beta-endorphin and cortisol concentrations, five horses performed a competition exercise test (CET; designed to simulate the speed and endurance test of a three-day event) in cool dry (CD) (20 degrees C/40% RH) and hot humid (30 degrees C/80% RH) conditions before (pre-acclimation) and after (post-acclimation) a 15 day period of humid heat acclimation. Plasma adrenaline and noradrenaline concentrations pre-acclimation were significantly increased compared with exercise in the CD trial at the end of Phases C (P<0.05) and D (P<0.05 and P<0.01, respectively) and at 2 min recovery (P<0.01), with adrenaline concentrations still elevated after 5 min of recovery (P<0.001). Plasma beta-endorphin concentrations were increased at the end of Phases C (P<0.05) and X (P<0.01) and at 5 and 30 min recovery (P<0.05) in the pre-acclimation session. Plasma cortisol concentrations were elevated after the initial warm up period pre-acclimation (P<0.01) and at the end of Phase C (P<0.05), compared with the CD trial. A 15 day period of acclimation significantly increased plasma adrenaline concentrations at 2 min recovery (P<0.001) and plasma cortisol concentration at the end of Phase B (P<0.01) compared with pre-acclimation. Acclimation did not significantly influence noradrenaline or beta-endorphin responses to exercise, although there was a trend for plasma beta-endorphin to be lower at the end of Phases C and X and after 30 min recovery compared with pre-acclimation. Plasma adrenaline, noradrenaline, beta-endorphin and cortisol concentrations were increased by exercise in cool dry conditions and were further increased by the same exercise in hot humid conditions. Exercise responses post-acclimation suggest that adrenaline and noradrenaline may play a role in the adaptation of horses to thermal stress and that changes in plasma beta-endorphin concentrations could be used as a sensitive indicator of thermal tolerance before and after acclimation. The use of plasma cortisol as a specific indicator of heat stress and thermal tolerance before or after acclimation in exercising horses appears limited.  相似文献   

4.
Nine Thoroughbred horses were assessed to determine the normal response of insulin, glucose, cortisol, plasma potassium (K) and erythrocyte K through conditioning and to exercise over 400 and 1,000 m. In addition, adrenaline, noradrenaline, cortisol, plasma K, erythrocyte K and L-lactate concentrations were evaluated in response to maximal exercise with and without the administration of acepromazine. Conditioning caused no obvious trends in plasma K, erythrocyte K, insulin or glucose concentration. Serum cortisol increased (P less than 0.05) from the initial sample at Week 1 to Weeks 4 and 5 (attributed to a response to training), and then decreased. During conditioning, three horses had low erythrocyte K concentrations (less than 89.3 mmol/litre). Further work is needed to define the significance of low erythrocyte K concentrations in the performance horse. In all tests maximal exercise increased plasma K, glucose and cortisol concentrations, whereas insulin and erythrocyte K concentrations decreased. Thirty minutes following exercise, plasma K and erythrocyte K concentrations returned to resting values; whereas glucose and cortisol concentrations continued to increase and the insulin concentration also was increased. The magnitude of the changes varied for pre-conditioned vs post-conditioned exercise tests and the duration of exercise. The administration of acepromazine prior to exercise over 1,000 m failed to alter the circulating noradrenaline and adrenaline concentrations in anticipation of exercise or 2 mins following exercise. Acepromazine administration, however, did cause lower L-lactate concentration 2 mins (P less than 0.03) and 30 mins (P less than or equal to 0.005) following exercise. Also, erythrocyte K showed a delayed return to baseline levels at 30 mins post exercise. Further evaluation of these trends may help explain the beneficial role acepromazine plays in limiting signs of exertional rhabdomyolysis when administered prior to exercise.  相似文献   

5.
The plasma concentrations of adrenaline, noradrenaline, dopamine, thyroxine, tri-iodothyronine, cortisol, insulin and glucose were estimated in lambs aged one to five hours during basal metabolism and then during summit metabolism (the maximum thermogenic response to cold stress). The increase in metabolic rate from basal metabolism to summit metabolism was associated with marked increases in the plasma levels of adrenaline, noradrenaline, cortisol and glucose and a decrease in the plasma level of insulin. There were no quantitative relationships between summit metabolic rate and the plasma levels of any of the hormones measured. These findings suggest that the marked lamb-to-lamb variation in heat production capacity found here and elsewhere cannot be directly attributed to variation in the activities of the sympathetic nervous system, the thyroid, the adrenal cortex or the pancreas. Concurrent estimations of respiratory quotient suggested that the newborn lamb has a marked dependence on carbohydrate as an energy substrate at high rates of heat production.  相似文献   

6.
We validated the use of urine to monitor changes in the activity of both the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS) in swine. Ten pregnant sows were fitted with venous catheters 3 wk after mating. In the early (wk 6), middle (wk 9), and late (wk 14) stages of gestation, blood and urine were collected over 24 h to monitor diurnal changes in plasma cortisol, urinary cortisol, and urinary catecholamines (norepinephrine [NE] and epinephrine [EPI]). Dexamethasone suppression tests (DST) and ovine corticotropin-releasing hormone (CRH) challenge tests were also performed at each stage of gestation. All plasma and urinary values changed markedly around the clock. Diurnal variations of urinary cortisol were comparable to those in plasma, with a late nocturnal peak and a trough occurring in the evening. During the dark period, urinary catecholamines were lower than during the light period. Norepinephrine increased sharply after lights came on and peaked after meal time. Epinephrine began to rise at the end of the dark period and peaked just before meal time. Average plasma cortisol increased with the stage of gestation, due to higher levels during daylight hours. Dexamethasone at 2000 (20 microg/kg i.v.) decreased plasma cortisol at 0830 and nocturnal cortisol excretion. The magnitude of the decrease in plasma ACTH and urinary cortisol after DST was lower in late than in early and midgestation, indicating increased feedback resistance at that stage. The CRH (1 microg/kg i.v.) increased plasma and urinary cortisol. Peak levels occurred 30 min and 2 to 3 h after the injection, respectively. Catecholamines and cortisol in urine produced during the night (2000 to 0800) and the early morning (0400 to 0800 and 0800 to 0900) were highly correlated with their 24-h excretion rate. These results indicate that it is possible to monitor changes in the HPA axis and SNS activity through urinary measurements in pigs.  相似文献   

7.
Previous data show that, in horses, plasma atrial natriuretic peptides (ANP and NT-ANP) remain elevated for a long time after exercise. To study whether exercise-induced changes in hormonal and fluid balance explain this, we measured plasma concentrations of COOH- and NH2-terminal atrial natriuretic peptides (ANP(99-129) and NT-ANP(1-98) together with arginine vasopressin (AVP), adrenocorticotrophin (ACTH), beta-endorphin, cortisol, catecholamines, and indicators of fluid balance in six Finnhorses after a graded submaximal exercise test on a treadmill. After exercise, AVP and catecholamines diminished rapidly; atrial peptides, ACTH, beta-endorphin, and cortisol remained elevated longer. ANP reached its peak value at 5 min and NT-ANP at 30 min post-exercise. At 60 min, ANP was still significantly increased and NT-ANP even above its level at the end of exercise. The different temporal patterns of ANP and NT-ANP are most probably explained by differences in their plasma half-lives. The post-exercise increase in NT-ANP indicates that the release of atrial peptides is stimulated during recovery after exercise. The rapid decrease in AVP and catecholamines suggests that these hormones do not explain the long-lasting increase in atrial peptides. Cortisol remained elevated longer and it may have contributed to some extent. After exercise, the packed cell volume (PCV) decreased more slowly than plasma total protein and electrolytes, which refers to a slow post-exercise return in blood volume. Taken together, the present results show that the long-lasting post-exercise increase in plasma atrial peptides in horses is most probably explained by elevated central blood volume and that the role of vasoactive hormones is small.  相似文献   

8.
Catecholamines seem to play a role in equine exercise physiology that is somewhat different from their role in human beings. In sport horses, a greater increase in plasma adrenaline (ADR) levels occurs in response to strenuous exercise as compared with human beings. However, it is not known whether this is true for breeds not specifically bred for sport. The aim of this study was to gather data on plasma catecholamine kinetics during exercise in a nonracing breed. We also attempted to evaluate the influence of the phases preceding the start of the exercise on the kinetics of these molecules. Four 2-year-old female Esperia ponies were made to perform a four-step exercise test on a treadmill. Blood samples were collected in the box (basal 1), in the treadmill room (basal 2), and at the conclusion of each step, using an automatic system. ADR and noradrenaline (NOR) levels were determined by high-pressure liquid chromatography. Results were analyzed using analysis of variance and the Student-Newman-Keuls test. As compared with basal 1, basal 2 showed a significant 19.6-fold increase for ADR and a 6.7-fold increase for NOR. The highest concentration was observed for both molecules at the end of the fourth step, with a significant 1.2-fold increase as compared with blood samples collected at basal 2 for ADR and a 2.4-fold increase for NOR. Therefore, in Esperia ponies, catecholamine showed a trend similar to that of Standardbreds and Thoroughbreds. The results reported in this study also revealed a marked increase in ADR in the phases preceding the beginning of physical activity. Therefore, the greater adrenergic activity in horses in response to exercise could be because of an anticipatory response.  相似文献   

9.
The changes were studied in the levels of catecholamines and L-DOPA in the control system of reproduction cycle (hypothalamus, hypophysis) and in adrenal glands of sheep after all-body irradiation with 60Co at the total dose of 6.7 Gy for seven days. The power input per hour of irradiation source was 0.039 Gy. The catecholamines (noradrenaline, dopamine and adrenaline) and L-DOPA were determined, after having been isolated from the tissues, by the method of spectral fluorimetry. After all-body exposition to gamma-radiation noradrenaline dropped in hypothalamus in comparison with the control group of sheep, most significantly in the rostral (by 74.2%) and caudal part (by 40%). A similar drop like in the case of noradrenaline was also observed in dopamine, the concentrations of which decreased in rostral hypothalamus by 72%, in medial hypothalamus by 94% and in caudal hypothalamus by 60%. Adrenaline shows a drop in hypothalamus, most significant in caudal region (by 62%). In relation with that the level of a precursor for the synthesis of catecholamines and L-DOPA has been changed which achieved, in the studied regions of hypothalamus in sheep, significantly lower levels than were determined in the control group of sheep. As regards the hypophysis, after irradiation no significant changes in the levels of noradrenaline and adrenaline were recorded, however, dopamine and L-DOPA dropped significantly (P less than 0.01). The exposition to gamma-radiation also causes a decrease in the concentrations of catecholamines and L-DOPA in the adrenal glands of sheep, most significant in noradrenaline (by 61%).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
The effect of transportation on blood cortisol and catecholamine levels, lymphocyte glucocorticoid receptor (GR) and beta-adrenergic receptor (beta-AR) concentrations was investigated in calves. Blood samples were collected from 24 six-month-old calves before departure (T(0)), on arrival (T(1)), and at 24 h (T(2)) and one week (T(3)) after arrival. Animals were loaded and transported about 950 km, from the Midy-Pyrenes region (Cahors, France) to the Piedmont region (Italy), over a total of 14 h. Serum cortisol levels and plasma catecholamines (adrenaline, noradrenaline) were determined by radioimmunoassay. Lymphocyte GRs and beta-ARs were measured through binding assays. A significant (P < 0.05) increase in cortisol and catecholamine concentrations was observed immediately after transport. The increase in hormone levels at time T(1) was negatively correlated with lymphocyte GR and beta-AR concentrations. At times T(2) and T(3), blood cortisol and catecholamine levels and lymphocyte GRs and beta-ARs returned to normal. The results demonstrate the activation of the hypothalamic-pituitary-adrenal axis and the catecholaminergic system in long-term transported calves. However, these systems returned to normal within 24 h after the end of transport.  相似文献   

11.
This study examined the role of the adrenergic system in the regulation of growth hormone (GH) secretion in sheep. Intravenous infusion of noradrenaline (0.5μg/kg per min for 2 hr) totally suppressed plasma GH concentrations. Concomitant treatment of animals with the β-adrenergic antagonist propranolol completely blocked the noradrenaline-induced suppression of GH. In contrast, intravenous injection of the centrally acting α2-agonist clonidine (2μg/kg) elicited a release of GH. To further investigate the central adrenergic regulation of GH secretion 10 μg of noradrenaline or adrenaline was microinjected (1μl) directly into the preoptic area of the hypothalamus of ovariectomized ewes. When the time of injection coincided with a GH trough period, both noradrenaline and adrenaline caused an increase in plasma GH concentrations, whereas if the injection coincided with an endogenous pulse of GH no additional GH response was obtained. In conclusion, these results provide evidence for the involvement of the adrenergic system in the regulation of GH secretion in sheep. Centrally, adrenergic pathways exert a stimulatory effect on GH release via an α2-adrenergic system, whereas peripherally adrenergic pathways exert an inhibitory effect via β-adrenergic mediated mechanisms. Furthermore, adrenergic stimulation of the preoptic area may inhibit somatostatin activity and directly facilitate a GH pulse. Alternatively, adrenergic innervation of the preoptic area may influence neurons (somatostatin or other) that project to the arcuate nucleus and stimulate the release of GH-releasing factor.  相似文献   

12.
To test the effect of nandrolone on their recovery, six adult half-bred riding horses performed a competition exercise test (CET) and a standardized exercise test (SET) on consecutive days before and after a 2-week treatment with the anabolic steroid nandrolone laurate. Blood samples were collected during and between these tests for the determination of red cell volume and concentrations of blood lactate, plasma glucose, non-esterified fatty acids, glycerol, triglycrides, erythropoietin, cortisol, insulin, and glucagon. Muscle biopsy specimens were taken immediately after the CET and before the SET for analysis of glycogen content, citrate synthase, and 3-hydroxyacyl CoA dehvdrogenase activity. Nandrolone administration increased the rate of muscle glycogen repletion after exercise, an increase that may be explained by increased glucose output by the liver, higher plasma insulin concentration, and increased insulin-independent glucose transport, but not by better availability of lipid fuels during recovery.  相似文献   

13.
A study was performed on the distribution of catecholamines (noradrenaline, dopamine and adrenaline) and L-DOPA in the hypothalamo-hypophysial region, as well as in the region of n. caudatus, which participate in the control of sexual activities in sheep. After isolation in the activated aluminium oxide, the catecholamine concentration was determined spectrophotometrically. Hypothalamus was divided into three regions: rostral, medial and caudal. In the same regions of the cerebroneural system (CNS), the activity of the degradation enzyme monoaminooxidase (MAO) was determined by radiochemical method. 14C-tryptamine was as a substrate and the results were measured by means of scintillation spectrophotometer Packard. The distribution of catecholamines and L-DOPA in the hypothalamus of sheep is different. The largest proportion is that of noradrenaline in caudal hypothalamus (1.84 +/- +/- 0.36). The dopamine levels in hypothalamus are quite balanced though substantially lower than those of noradrenaline (from 0.22 to 0.31 micrograms/g). The concentrations of adrenaline and L-DOPA in the sheep hypothalamus are low. The sheep hypophysis contains more noradrenaline (1.70 +/- 0.38), adrenaline content amounts to 1.30 +/- 0.28. L-DOPA and dopamine occur in this region at low concentrations. In comparison with the other regions of sheep brain, high dopamine concentrations (2.0 +/- 0.58 micrograms/g) and higher L-DOPA levels were determined in n. caudatus. The activity of the degradation enzyme monoaminooxidase in the cerebroneural system of sheep is different. The highest MAO activity was determined in the rostral hypothalamus (1100 pmol X mg-1 X min-1), lower in its caudal and medial region.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

14.
The effect of dynamic exercise on complete blood cell count, lymphocyte β-adrenergic receptor and plasma catecholamine (adrenaline and noradrenaline) levels in horses performing different disciplines were investigated during rest and after exercise. Blood samples were collected from jumping horses (n=6), Arabian Endurance horses (n=6) and Standardbred trotters (n=6) before and immediately after competition. Dynamic exercise caused a significant increase in red blood cell count (Standardbred trotters: P=0.0012), haemoglobin concentration (jumping horses: P=0.001; Standardbred trotters: P=0.01), haematocrit percentage (Standardbred trotters: P=0.005), neutrophil percentage (jumping horses: P=0.0003), lymphocyte percentage (jumping horses: P=0.0003), monocyte percentage (Standardbred trotters: P=0.0008), lymphocyte β-AR numbers (jumping horses: P=0.01; Arabian Endurance horses: P=0.016; Standardbred trotters: P=0.05), plasma adrenaline concentration (Standardbred trotters: P=0.0001) and plasma noradrenaline levels (Standardbred trotters: P=0.003). It is concluded that acute increases in plasma catecholamine concentrations depended on the exercise performed and may induce up-regulation of β-AR in equine lymphocytes. However, the exact mechanism of β-AR up-regulation still remains unclear.  相似文献   

15.
The aim of the present study was to determine changes in the density of sympathetic nerves in porcine ovaries with dexamethasone (DXM)-induced cysts and the alterations in steroidogenic activity and amounts of catecholamines in the affected gonads. Cystic ovaries were supplied by numerous sympathetic nerve fibers. The amount of noradrenaline in the cysts (fluid, wall) was significantly higher than in the large follicles of the control group. After DXM injections, the amounts of noradrenaline and adrenaline significantly increased in the walls of small and medium-sized follicles. In the cysts (fluid, wall) the levels of androgens and estrogens were significantly lower, whereas progesterone was higher in the cystic wall. DXM administration led to a significant increase in the estrone content in the fluid of small follicles. Moreover, a decrease in the amounts of progesterone and androgens was found in the follicular fluid and walls of medium-sized follicles. DXM injections resulted in a significant increase in the immunoexpression of P450(scc) and 3beta-HSD in the cysts, a significant increase of P450(scc) in the follicles, and a decrease of 3beta-HSD and P450(arom). The present study shows that the DXM treatment leads to an increase in the density of intraovarian sympathetic nerves, paralleled by the amount of catecholamines, and that it is capable of changing the steroidogenic activity of porcine ovary bearing cysts. Thus, it appears possible that these events may be, at least partly, involved in the pathogenesis of this disorder.  相似文献   

16.
Eight standardbred horses trotted on a treadmill for 55 mins at a sub-maximal speed of 5m/sec and subsequently performed an exercise test consisting of 2 min intervals at increasing speed. Heart (HR) and respiratory (Rf) rates and venous blood samples were obtained before, during and for 5 mins after exercise. Gluteus medius muscle biopsies and rectal temperatures were taken before and after exercise. The mean HR was 132/min and the mean Rf was 156/min during the 5m/sec trotting. With 5m/sec exercise, plasma free fatty acids (FFA), glucose, creatinine and cortisol concentrations increased markedly. Blood lactate increased slightly and plasma potassium increased initially and then decreased with a lengthened duration of trotting. Within 5 mins post exercise plasma FFA, glucose and cortisol concentrations continued to rise, whereas creatinine and lactate levels declined slightly and potassium concentrations declined rapidly to below resting values. The mean intramuscular (im) glycogen utilisation was 86 mmol/kg, no significant changes occurred in creatine phosphate (CP), adenosine triphosphate (ATP) and glucose-6-phosphate (G-6-P) concentrations and muscle lactate decreased significantly. During the second exercise test mean HR was 215/min and Rf 126/min at top speed. No significant change was seen in plasma glucose whereas cortisol levels rose to a lesser extent, and creatinine lactate, ammonia and potassium concentrations to a greater extent, compared to 5 m/sec trotting. Post exercise, these parameters continued to increase except for creatinine which declined slightly and potassium which decreased rapidly. The mean im glycogen utilisation was 144 mmol/kg, ATP concentrations were unaltered, CP declined, lactate and G-6-P increased during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

17.
Gender differences have not been shown in relation to the immune system in athletic horses. The aim of the present paper was to elucidate gender differences in the non-specific immune response of the polymorphonuclear neutrophil (PMN), plasma glucose and in hormones before and after an exercise in the lactate threshold (LT). A group of 12 Anglo-Arabian horses (6 females and 6 males, 4-7 years old) was observed. A submaximal exercise test was carried out at the LT. The results showed that males had a higher PMN percentage, plasma glucose values, Adherence index (AI) and random migration than females. Also, females showed significant negative correlations between cortisol and catecholamines with PMN and glucose with phagocytosis, and positive ones between AI and catecholamines. In males, negative correlations were established between random migration and chemotaxis with cortisol, and positive ones between cortisol and phagocytosis.  相似文献   

18.
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   

19.
Post operative pain was evaluated in 13 horses subjectively and by measuring pre-defined behavioural and physiological variables. Twelve of the horses had undergone painful orthopaedic surgery and one had developed post anaesthetic myopathy and nerve damage after radiological examination under general anaesthesia. Venous blood samples were collected for catecholamine, ß-endorphin and cortisol assays before premedication and up to 72 h after surgery. No differences were seen in head position, ground pawing or use of the operated leg between the pre-and post anaesthetic periods. The subjective pain score was higher at 4 h after anaesthesia than the pre-operative score. Mean plasma ß-endorphin concentration increased above pre-operative values at 6 and 12 h after anaesthesia. Anaesthesia and surgery did not change mean plasma cortisol concentration, but it was lower in samples collected at 48 and 72 h. There was considerable individual variation in plasma catecholamine concentrations. At some time points the plasma concentration of catecholamines was higher than before premedication, but the maximal concentrations for adrenaline, noradrenaline and dopamine did not occur simultaneously. Heart rate was increased at 2 and 4 h, and abdominal sounds were decreased at 2 h. Packed cell volume was decreased in samples taken 2 to 12 h after anaesthesia. There was poor correlation between all the parameters measured in the study The subjective pain score and the plasma ß-endorphin concentration correlated with each other at several time points, but not during the immediate post operative period.  相似文献   

20.
The aim of the present study was to characterise the quantitative sweating response of the horse to beta2-adrenergic stimulation. The sweating responses of 6 horses to the randomised infusion of 8 different adrenaline concentrations (0.025, 0.05, 0.075, 0.1, 0.2, 0.4, 1.0 or 2.0 microg/kg bwt/min), was investigated. Sweating rate (SR) and skin temperature (TSK) on the neck (N) and gluteal region (G), and plasma adrenaline and noradrenaline concentrations were measured. Peak SR was approximately 15 (N) and approximately 9 g/m2/min (G) during infusion of both 1.0 and 2.0 microg/kg bwt/min adrenaline. Sweat produced per nmol/l plasma adrenaline peaked during the infusion of 0.075 microg/kg bwt/min adrenaline. Higher adrenaline infusion concentrations resulted in a progressive decrease in the amount of sweat produced per nmol/l plasma adrenaline and a plateau of 6 g/m2/(nmol/l) plasma adrenaline was reached for infusions between 1.0 and 2.0 microg/kg bwt/min. Peak SR were far lower than we have previously reported during exercise. There was no evidence of sweat gland fatigue or vasoconstriction during infusion, suggesting saturation of sweat gland beta2 receptors. We conclude that sweating in the horse is under dual control from a combination of hormonal and neural mechanisms.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号