Effects of 3-day bed rest on physiological responses to graded exercise in athletes and sedentary men.

To test the hypotheses that short-term bed-rest (BR) deconditioning influences metabolic, cardiorespiratory, and neurohormonal responses to exercise and that these effects depend on the subjects' training status, 12 sedentary men and 10 endurance- and 10 strength-trained athletes were submitted to 3-day BR. Before and after BR they performed incremental exercise test until volitional exhaustion. Respiratory gas exchange and heart rate (HR) were recorded continuously, and stroke volume (SV) was measured at submaximal loads. Blood was taken for lactate concentration ([LA]), epinephrine concentration ([Epi]), norepinephrine concentration ([NE]), plasma renin activity (PRA), human growth hormone concentration ([hGH]), testosterone, and cortisol determination. Reduction of peak oxygen uptake (VO(2 peak)) after BR was greater in the endurance athletes than in the remaining groups (17 vs. 10%). Decrements in VO(2 peak) correlated positively with the initial values (r = 0.73, P < 0.001). Resting and exercise respiratory exchange ratios were increased in athletes. Cardiac output was unchanged by BR in all groups, but exercise HR was increased and SV diminished in the sedentary subjects. The submaximal [LA] and [LA] thresholds were decreased in the endurance athletes from 71 to 60% VO(2 peak) (P < 0.001); they also had an earlier increase in [NE], an attenuated increase in [hGH], and accentuated PRA and cortisol elevations during exercise. These effects were insignificant in the remaining subjects. In conclusion, reduction of exercise performance and modifications in neurohormonal response to exercise after BR depend on the previous level and mode of physical training, being the most pronounced in the endurance athletes.     

Prolonged bed rest impairs response of the small arteries to cold pressor test

Cold pressor test (CPT) has been known to increase vascular resistance through adrenergic stimulation. To assess the effect of prolonged bed rest (BR) on sympathetic neural control, blood flow velocity of the proper palmar digital artery (resistance vessel) was measured in 10 healthy volunteers during a 90 seconds CPT by pulsed Doppler ultrasound using a 7.5 MHz linear transducer before and after 20 days BR. Blood flow velocity in the proper palmar digital artery decreased during the first half of the CPT both before and after BR, but decreases in peak flow velocity became less prominent (p<0.05) after BR (-48+/-20%) than before bed rest (-61+/-25%). The only subject whose lower body negative pressure tolerance time was prolonged after BR showed prominent decreases in peak flow velocity during the first half of the CPT after BR. Peak flow velocity returned to the pre-test value during the latter half of the CPT in 7 subjects before BR, but in only 2 subjects after BR (p<0.05). Thus, 20 days BR impairs the response of the small digital arteries to CPT, suggesting that a decrease in a adrenergic stimulation occurs after prolonged BR.     

Effects of a 30-km race upon salivary lactate correlation with blood lactate

Blood lactate has been used to determine the aerobic capacity and long distance performance. Recently, a new methodology has been suggested to supplant the invasive blood lactate techniques. Salivary lactate has received attention because it shows high correlation to blood lactate in progressive overload test. We evaluated the correlation between salivary and blood lactate during a long distance run and assessed possible changes in salivary lactate concentration. Fifteen expert marathon racers ran 30 km as fast as possible. Saliva and 25 muL of blood were collected at rest and at each 6 km for lactate determination. Blood lactate concentration increased in the 6th km and then remained constant until the end of the race. Salivary lactate increased after 18 km in relation to basal. We found high correlations between blood and saliva absolute lactate (r=0.772, p<0.05) and the blood lactate relative concentration corrected by protein (r=0.718, p<0.05). The highest correlation found between absolute and relative salivary lactate was r=0.994 (p<0.001). Our results show that it is possible to use salivary lactate with absolute values or relative protein concentration. In addition, salivary lactate showed a high correlation with blood lactate in endurance events.     

Changes in cortical excitability and blood lactate after a fatiguing hand-grip exercise

Excitability of primary hand motor cortex (PHMC), evaluated with transcranial magnetic stimulation by using the “1?mV resting motor threshold” method, and capillary blood lactate were measured at the end, as well as 5 and 10?min after a fatiguing hand-grip exercise. The relation between blood lactate and the amplitudes of motor-evoked potentials showed a significant direct proportionality. Blood lactate seems to exert a protective role on PHMC against fatigue reduction during extremely intensive isometric exercises.     

Blood lactate accumulation in intermittent supramaximal exercise

Blood lactate accumulation rate and oxygen consumption have been studied in six trained male runners, aged 20 to 30 years. Subjects ran on a treadmill at a rate representing 172 +/- 5% VO2max for four 45 s sessions, separated by 9 min rest periods. Oxygen consumption was measured throughout. Blood lactate was determined in samples taken from the ear and VO2 was measured at the end of each exercise session, and two, five and nine minutes later. After the fourth exercise session, the same measurements were made every five min for 30 min. 4 subjects repeated a single exercise of the same type, duration and intensity and the same measurements were taken. With repetitive intermittent exercise, gradual increases in blood lactate concentration [( LA]b) occurred, whereas its rate of accumulation (delta[LA]b) decreased. The amount of oxygen consumed during each 45 s exercise session remained unchanged for a given subject. After cessation of intermittent exercise, the half-time of blood lactate was 26 min, whereas it was only 15 min after a single exercise session. VO2 values, on the other hand, returned to normal after 15 to 20 min. All other conditions being equal, the gradual decrease in delta[LA]b during intermittent exercise could be explained if the lactate produced during the first exercise session is used during the second period, and/or if the diffusion space of lactate increases. The diffusion space seems to be multi-compartmental on the basis of half-time values noted for [LA]b after intermittent exercise, compared with those noted after a single exercise session.(ABSTRACT TRUNCATED AT 250 WORDS)     

Seven days of bed rest decrease insulin action on glucose uptake in leg and whole body

Impaired glucose tolerance develops in normal humans after short-term bed rest. To elucidate the mechanism, insulin action on whole body glucose uptake rate (WBGUR) and leg glucose uptake rate (LGUR) was measured by sequential euglycemic clamp technique combined with femoral arterial and venous cannulation at insulin concentrations of 10 +/- 1, 18 +/- 1, 37 +/- 2, and 360 +/- 15 microU/ml. Studies were performed before (C) and after (BR) 7 days of strict bed rest. WBGUR was significantly lower after bed rest than before (5.5 +/- 0.4 and 7.2 +/- 0.8 mg.min-1.kg-1, respectively) when insulin was 37 microU/ml. LGUR was even more markedly depressed by bed rest, being 0.6 +/- 0.1, 0.9 +/- 0.2, and 2.8 +/- 0.4 mg.min-1.kg leg-1 (BR) compared with 0.9 +/- 0.1, 1.7 +/- 0.4, and 5.9 +/- 0.5 mg.min-1.kg leg-1 (C) (P less than 0.05) at the three lower insulin concentrations. At these insulin concentrations also, lactate release and glucose oxidation and glycogen storage estimated by indirect calorimetry were lower in the leg after bed rest. At the highest insulin dose WBGUR was similar on BR and C days, while LGUR was lower after bed rest. In conclusion, 7 days of bed rest decrease whole body insulin action, a fact that is explained by decreased insulin action in inactive muscle.     

Blood Lead Levels and Increased Bronchial Responsiveness

The immune system is one of the targets most sensitive to lead toxicity, and the association between lead exposure and serum immunoglobulin E (IgE) has been published. Recent studies also reported that lead caused the development of IgE-mediated allergy. To investigate whether blood lead levels contribute to other allergic conditions, we examined the effect of blood lead on bronchial responsiveness (BR) in the general population. We performed a cross-sectional study with adults aged 19 to 58 years in a Korean community. Blood lead level and the methacholine provocation test were performed. The overall mean blood lead level was 2.9 microg/dl, and the mean BR index was 1.14. The percent of subjects with clinically diagnosed asthma was 21 (4%) and there was no difference in blood lead level with and without asthma. In the multiple regression model, the elevation of blood lead level was related to the increase of BR after adjusting for age, sex, height, smoking status, and the presence of asthma. Blood lead level was significantly associated with increased BR that came from the elevation of the IgE level with lead exposure. Lead may contribute to the increase of asthma and other allergic conditions.     

Venous blood gases and lactates of wild loggerhead sea turtles (Caretta caretta) following two capture techniques

During summer of 2001, venous blood gases were determined in loggerhead sea turtles (Caretta caretta) captured by trawl (n = 16) in coastal waters of South Carolina and Georgia (USA) as part of a sea turtle census program and captured in pound nets (n = 6) in coastal North Carolina (USA) during a study of sea turtle population biology. Trawls were towed for 30 min, so turtles captured were forcibly submerged for < or = 30 min. Pound nets are passive gear in which fish and sea turtles are funneled into a concentrated area and removed periodically. Sea turtles in pound nets are free to surface and to feed at will. Blood was obtained from the dorsal cervical sinus as quickly as possible after landing on the boat (range 2-10 min trawl, 1-2 min pound net) and at 30 min after landing just prior to release. Blood gases including pH, partial pressures of O2 and CO2 (pO2, pCO2), and lactate were measured within 10 min. Instrument measurements for pH, pO2, and pCO2 made at 37 C were corrected to cloacal temperature and HCO3- was calculated from temperature-corrected pH and pCO2. Venous blood pH and bicarbonate were higher, and pO2 and lactate were lower from pound net-captured turtles compared to trawl captured turtles at the initial sampling time. In pound net turtles, pH and bicarbonate declined and lactate increased during 30 min on deck. In trawled sea turtles, venous blood pH increased and pCO2 and pO2 decreased during the 30 min on deck. Both capture systems caused perturbations in blood gas, acid-base, and lactate status, though alterations were greater in trawl captured turtles.     

Decreased exercise muscle lactate release after high altitude acclimatization

Blood lactate concentration during exercise decreases after acclimatization to high altitude, but it is not clear whether there is decreased lactate release from the exercising muscle or if other mechanisms are involved. We measured iliac venous and femoral arterial lactate concentrations and iliac venous blood flow during cycle exercise before and after acclimatization to 4,300 m. During hypoxia, at a given O2 consumption the venous and arterial lactate concentrations, the venous and arterial concentration differences, and the net lactate release were lower after acclimatization than during acute altitude exposure. While breathing O2-enriched air after acclimatization at a given O2 consumption the venous and arterial lactate concentrations and the venous and arterial concentration differences were significantly lower, and the net lactate release tended to be lower than while breathing ambient air at sea level before acclimatization. We conclude that the lower lactate concentration in venous and arterial blood during exercise after altitude acclimatization reflected less net release of lactate by the exercising muscles, and that this likely resulted from the acclimatization process itself rather than the hypoxia per se.     

胆红素自由基对大鼠肝细胞损伤作用的研究

用不同自由基源处理的胆红素与鼠肝细胞相互作用,结果表明：胆红素自由基可引起鼠肝细胞脂质过氧化,使总谷胱甘肽及ＧＳＳＧ水平明显下降,细胞损伤后,乳酸脱氢酶外漏,上述结果与自由基浓度正相关,而与其种类无关,牛血清白蛋白有明显的抑制作用。差示光谱表明：胆红素可能与细胞色素Ｐ－４５０快速形成络合物。根据以上结果,重点讨论了胆红素自由基对肝细胞损伤的化学本质及其与胆结石形成的关系。     

The Effect of Citrulline/Malate on Blood Lactate Levels in Intensive Exercise

The purpose of this study was to examine the effects of Citrulline/Malate supplementation with intensive training on blood lactate level in active handball players. The athletes were subjected to intense training for 4 weeks, 4 days a week, mainly pre-season strength and technique training. In this training period, stimol group (n = 11) athletes were given stimol 3 times a day as 1 g for breakfast, 1 g for lunch, and 1 g for dinner while the placebo group (n = 11) athletes were given only placebo in the same dosage and the same color at the same time. Blood lactate levels in athletes were measured 4 times, prior to and after a 1-month program as follows: rest (R), end effort (EE), recuperation 5 min (R5 m), and recuperation 20 min (R20 m). Blood lactate levels were compared both as intra-group and between the groups. In intra-group comparison, no change was observed in blood lactate levels in placebo group while a significant difference was found in the levels of stimol group as p < 0.05 with a 49.8% decrease in blood lactate level. In the measurements between groups, in the post-test measurements made after the training period, significant differences as p < 0.05 were found with a 60.7% decrease in blood lactate level EE. Considerable decline was seen especially immediately after exercise in blood lactate levels of the athletes being given stimol supplement. In this case, we can say that Citrulline/Malate supplementation may contribute positively to the performance of athletes and may help postpone fatigue at excessive or prolonged activity.     

Experimental infection with Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis in the marmoset, Callithrix penicillata (Primates:Callithricidae)

Fourteen marmosets (Callithrix penicillata) were inoculated intradermally with promastigotes and/or amastigotes of Leishmania (Viannia) braziliensis (L. (V) b.) strains MHOM/BR/83/LTB-300 MHOM/BR/85/LTB-12 MHOM/BR/81/LTB-179 and MHOM/BR/82/LTB-250. The evolution of subsequent lesions was studied for 15 to 75 weeks post-inoculation (PI). All but 3 of the L. (V) b. injected marmosets developed a cutaneous lesion at the point of inoculation after 3 to 9 weeks, characterized by the appearance of subcutaneous nodules containing parasites. Parasites were isolated by culture (Difco Blood Agar) from all 11 positive animals. The maximum size of the lesions was variable and ranged between 37 mm2 to 107 mm2. Ulceration of primary nodules became evident after 3 to 12 weeks in all infected marmosets, but was faster and larger in 5 of the 11 animals. The active lesions persisted in 9 out of 11 Callithrix until the end of the observation period, which varied from 15-75 weeks. In 3 animals spontaneous healing of their lesions (13 to 25 weeks, PI) was observed but with cryptic parasitism. In another 2 infected animals there was regression followed by reactivation of the cutaneous lesions. The appearance of smaller satellite lesions adjacent to primary ones, as well as metastatic lesions to the ear lobes, were documented in 2 animals. Promastigotes of L. (Leishmania) amazonensis (L. (L) a.) MHOM/BR/77/LTB-16 were inoculated in 1 marmoset. This animal remained chronically infected for 6 months and the lesion developed in a similar manner to L. (V) b. infected marmosets. No significant differences in clinical and parasitological behaviour were observed between promastigote or amastigote derived infections of the 2 species.(ABSTRACT TRUNCATED AT 250 WORDS)     

Kinetic analysis of the shift of aerobic to anaerobic metabolism in rats during acute cyanide poisoning

Blood concentrations of cyanide, lactate, glucose, oxypurines and allantoin were determined in rats sampled at 10 min after the intraperitoneal administration of various concentrations of potassium cyanide. Lactate and oxypurines in plasma increased biquadratically with increase in the cyanide concentration in blood. The concentrations of cyanide for half maximal effect were 1.63 μg/ml for lactate and 2.09 μg/ml for oxypurines. Plasma glucose increased quadratically with increase in the cyanide concentration, and the marked increase was observed where plasma lactate concentration became near maximal. Plasma allantoin concentrations were not significantly changed throughout the experiments. The present results indicate that determination of plasma oxypurines as well as lactate is an excellent parameter for tissue hypoxia.     

Effect of space flight and head-down bedrest on neuroendocrine response to metabolic stress in physically trained subjects

The aim of this study was to evaluate the association of plasma epinephrine (EPI) and norepinephrine (NE) responses to insulin induced hypoglycemia (ITT) 3 weeks before the space flight (SF), on the 5th day of SF, on the 2nd and 16th days after the landing in the first Slovak astronaut, and before and on the 5th day of prolonged subsequent head-down (-6 degrees) bed rest (BR) in 15 military aircraft pilots. Blood samples during the test were collected via cannula inserted into cubital vein, centrifuged in the special appliance Plasma-03, frozen in Kryogem-03, and at the end of the 8-day space flight transferred to Earth in special container for hormonal analysis. Insulin hypoglycemia was induced by i.v. administration of 0.1 IU/kg BW insulin (Actrapid HM) in bolus. Insulin administration led to a comparable hypoglycemia in pre-flight, in-flight conditions and before and after bed rest. ITT led to a pronounced increase in EPI levels and moderate increase in NE in pre-flight studies. However, an evidently reduced EPI response was found after insulin administration during SF and during BR. Thus, during the real microgravity in SF and simulated microgravity in BR, insulin-induced hypoglycemia activates the adrenomedullary system to less extent than at conditions of the Earth gravitation. Post-flight changes in EPI and NE levels did not significantly differ from those of pre-flight since SF was relatively short (8 days) and the readaptation to Earth gravitation was fast. It seems, that an increased blood flow in brain might be responsible for the reduced EPI response to insulin. Responses to ITT in physically fit subjects indicate the stimulus specificity of deconditioning effect of 5 days bed rest on stress response. Thus, the data indicate that catecholamine responses to ITT are reduced after exposure to real as well as simulated microgravity.     

Immediate and delayed effects of gill-net capture on acid-base balance and intramuscular lactate concentration of gummy sharks, Mustelus antarcticus

Many sharks are captured as untargeted by-catch during commercial fishing operations and are subsequently discarded. A reliable assessment of the proportion of discarded sharks that die post-release as a result of excessive physiological stress is important for fisheries management and conservation purposes, but a reliable physiological predictor of post-release mortality has not been identified. To investigate effects of gill-net capture on the acid-base balance of sharks, we exposed gummy sharks, Mustelus antarcticus, to 60 min of gill-net capture in a controlled setting, and obtained multiple blood and muscle tissue samples during a 72-h recovery period following the capture event. Overall mortality of gummy sharks was low (9%). Blood pH was significantly depressed immediately after the capture event due to a combination of respiratory and metabolic acidosis. Maximum concentrations of plasma lactate (9.9 ± 1.5 mmol L(-1)) were measured 3h after the capture event. Maximum intramuscular lactate concentrations (37.0 ± 4.6 μmol g(-1)) were measured immediately after the capture event, and intramuscular lactate concentrations were substantially higher than plasma lactate concentrations at all times. Sharks in poor condition had low blood pH and high intramuscular lactate concentration, but blood pH does not appear to be a reliable predictor of survival. Suitability of intramuscular lactate concentration as predictor of delayed mortality deserves further investigation.     

Determination of the anaerobic threshold and maximal lactate steady state speed in equines using the lactate minimum speed protocol

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.     

Serotonin mediates rapid changes of striatal glucose and lactate metabolism after systemic 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") administration in awake rats

The pathway for selective serotonergic toxicity of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") is poorly understood, but has been linked to hyperthermia and disturbed energy metabolism. We investigated the dose-dependency and time-course of MDMA-induced perturbations of cerebral glucose metabolism in freely moving rats using rapid sampling microdialysis (every minute) coupled to flow-injection analysis (FIA) with biosensors for glucose and lactate. Blood samples for analysis of glucose and lactate were taken at 30-45 min intervals before and after drug dosing and body temperature was monitored by telemetry. A single dose of MDMA (2-10-20 mg/kg i.v.) evoked a transient increase of interstitial glucose concentrations in striatum (139-223%) with rapid onset and of less than 2h duration, a concomitant but more prolonged lactate increase (>187%) at the highest MDMA dose and no significant depletions of striatal serotonin. Blood glucose and lactate levels were also transiently elevated (163 and 135%) at the highest MDMA doses. The blood glucose rises were significantly related to brain glucose and brain lactate changes. The metabolic perturbations in striatum and the hyperthermic response (+1.1 degrees C) following systemic MDMA treatment were entirely blocked in p-chlorophenylalanine pre-treated rats, indicating that these effects are mediated by endogenous serotonin.     

Ease of calving, blood chemistry, insulin and bovine growth hormone of newborn calves derived from embryos produced in vitro in culture systems with serum and co-culture or with PVA

Blood chemistry (pH, pCO2, pO2, glucose, lactate) as well as plasma insulin and growth hormone of calves derived from embryos produced under 2 different in vitro culture systems (modified SOFaa with 20% serum and co-culture with bovine oviduct epithelial cells [IVP serum, n=8] or with 3 mg/mL PVA [IVPdefined, n=6]) were compared with those of calves derived from AI (n=5). Calvings were classified according to the ease (unassisted, light traction, heavy traction). Blood samples were taken from the jugular vein of calves at 5, 15, 30 and 60 min, and at 2, 3, 6, 12, 18 and 24 h after delivery, then daily for 6 d. At the second day of life after 4 feedings and a 4-h fasting period, a glucose tolerance test was performed to evaluate glucose metabolism and insulin secretion. Calves in the IVP serum group had higher birth weights than AI calves (LS mean +/- SEM, IVP serum: 45.2 +/- 1.4 kg vs AI: 40.4 +/- 1.7 kg; P < 0.05), while the birth weights of calves in the IVP defined group were in between (IVPdefined: 41.9 +/- 1.6 kg). More IVP serum calves (75%) needed assistance than IVP defined (33%) or AI (40%) calves. The effect of ease of calving vs the effect of embryo culture was compared in relation to blood parameters at birth. There was an effect of ease of calving but not of embryo culture conditions on blood pH, lactate and PCO2. Calves requiring heavy traction had lower pH during the first 3 h after calving, a higher lactate during the first 60 min after calving and a higher pCO2 the first 2 h after calving than calves born unassisted. Calves requiring heavy traction also had lower pH the first 2 h and higher lactate the first 3 h after calving than calves born by light traction. IVP defined calves had lower lactate than IVP serum calves the first 60 min after calving. At 6 h after delivery, all blood parameters had stabilized. There was no effect of either embryo culture or ease of calving on basal insulin and growth hormone level, or the ability of the calves to handle glucose postnatally and during a glucose tolerance test.     

Skeletal muscle lactate release and glycolytic intermediates during hypercapnia

The effects of respiratory acidosis on glycolysis in the autoperfused canine gastrocnemius-plantaris were studied using anesthetized dogs that were ventilated either with air (n = 30) or with 4% CO2-21% O2-75% N2 (n = 30). The left muscle group was stimulated at 3 Hz for up to 20 min, after which the active and the contralateral resting muscles were removed and frozen in liquid N2. Blood flow, VO2, Vco2, and tension development were unaffected by CO2. Glycogen catabolism was not affected, but lactate release (La) was lower (P less than 0.05) during activity with CO2; and greater fructose 6-phosphate, fructose 6-phosphate/fructose 1,6-diphosphate, and alpha-glycerophosphate/dihydroxyacetone phosphate ratios resulted (P less than 0.05). With respiratory acidosis, muscle lactate tended to accumulate early in contractions, but a net lactate uptake occurred during the last 10 min of contractions. Thus, respiratory acidosis reduced lactate efflux and there was a net uptake late in the contraction period. Glycogen phosphorylase did not appear to be affected by the respiratory acidosis, but there was evidence of inhibition at the phosphofructokinase step as well as a tendency for lactate to accumulate within the muscle. La often occurred in a direction contrary to the muscle-venous lactate concentration difference with either air or CO2 and La also decreased far more rapidly over time than did the arterial-venous H+.     

Effects of postexercise supplementation of chicken essence on the elimination of exercise-induced plasma lactate and ammonia

We investigated the effects of chicken essence (CE) supplementation on exercise-induced changes of lactate and ammonia during recovery. In this randomized, double blind, crossover study, twelve healthy subjects performed a single bout of exercise to exhaustion, and then consumed either a placebo or CE within 5-min of the exercise cessation. Blood samples were collected before exercise, at exhaustion (0 minute), and 20, 40, 60, and 120 minutes, respectively during the recovery period. There were no differences in plasma glucose, creatine kinase, or heart rate responses between treatments. The exercise exhaustion significantly increased the levels of lactate and ammonia, and both measured values gradually declined during the recovery period. Ammonia levels at 40, 60, and 120 min. of the recovery period were observed lower significantly in the CE group, as compared to those in the placebo group. Additionally, lactate concentrations at 60 and 120 min were lower in the CE group, as compared to those in the placebo group. In conclusion, the main finding of this study was that CE supplementation after exercise reduces plasma lactate and ammonia levels. The results indicated that CE supplementation after an exhaustive exercise could enhance physiological recovery in humans.