Effect of exercise intensity and training on antioxidants and cholesterol profile in cyclists

The aim of this work was to evaluate the effect of different intensity of exercise and different training status on antioxidants and cholesterol profile in cyclists. 33 male cyclists (17 amateur and 16 professional cyclists) participated in this study. The amateurs all trained 14 +/- 1 h each week, and their VO(2) max was 62.5 +/- 1.8 ml/Kg x min; the professionals all trained 24 +/- 1 h each week, and their VO(2) max was 80.2 +/- 1.6 ml/Kg x min. Amateurs were submitted to the maximal and submaximal prolonged exercise tests. Professionals were submitted to a mountain stage (170 km) of cycling competition. Serum lipid and cholesterol profile (triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol) and plasma antioxidant capacity (ascorbic acid, alpha-tocopherol, retinol, beta-carotene and others) were measured before and after exercise tests. Hematological determinations (number of erythrocytes, hematocrit and hemoglobin concentration) and dietary intake were also measured. No significant differences were observed in basal values (before exercise tests) of amateur and professional cyclists. Negligible differences were found between dietary intake of amateur and professional cyclists, and also the results of hematological values showed there was no effect of degree of hydration or dietary intake on blood levels of studied antioxidant and lipid parameters. An increase in plasma levels of vitamin C, vitamin E, triglycerides and VLDL-cholesterol levels, and also a decrease of beta-carotene and LDL-cholesterol. were observed in well-trained professional cyclists after the cycling stage - an endurance exercise--but not in amateur cyclists. Amateur cyclists showed only mild increases in total cholesterol after maximal and submaximal exercise, while a rise in HDL-cholesterol was only observed after maximal exercise; none of these changes were observed in professional cyclists. Plasma levels of antioxidant vitamins and carotenes, and also serum lipids, total cholesterol and lipoprotein-cholesterol showed an overall response to exercise, and their increase and/or decrease must be explained as a consequence of the different training status of sportsmen and intensity and duration of exercise tests.     

Splenic respiratory compensation and blood volume in the newt

In the newt Triturus cristatus carnifex , reversible increase in size of the spleen is linked to the respiratory state of the animal: when the newt is exposed to the air, and thus well oxygenated, the spleen hoards erythrocytes; when immersed in still water, in an hypoxic state, the spleen releases erythrocytes into the bloodstream. In chlorobutanol-anaesthetized specimens exposed to the air, the maximum size reached by the spleen diminishes with a rise in temperature up to the disappearance of all congestion at 33°C. The blood volume of newts kept in humid air at 6°C and 18°C after anaesthesia varies from about 6–9 ml per 100 g of body weight, while the red blood cell count and haematocrit value remain stable. In anaesthetized specimens kept in still water at the same temperatures the blood volume is stable, at about 7 ml per 100 g, but the red cell count and haematocrit are notably higher. At 33°C, a critical temperature for the newts, the specimens in still water succumb while those in air present the same blood volume as at 18°C, but have a higher erythrocyte count and haematocrit value.     

Effect of breathing an oxygen-helium mixture under positive pressure on biochemical parameters

In 35 subjects the effect of breathing an oxygen-helium mixture or oxygen during 10 minutes under positive pressure of 40 hPa was studied. Immediately before positive-pressure breathing, in the last minute of this breathing, and 30 minutes after its and blood samples were taken for investigations. Positive-pressure breathing caused in both groups a rise-in the haematocrit value, total protein, albumin and glucose levels. The level of lactic acid rose during breathing oxygen by 74% and that of pyruvic acid increased by 44%, while during the use of the oxygen-helium mixture both these compounds failed to rise during positive-pressure breathing and 30 minutes after its completion.     

Haematology and serum biochemistry of captive unsedated chital deer (Axis axis) in Australia

Haematological and serum biochemical values were measured in blood samples collected over a 12-mo period from 37 unsedated chital deer (Axis axis). Stags and hinds, ranging in age from birth to maturity, were sampled. Haemoglobin, total erythrocyte and haematocrit values were low at birth and sex differences were not apparent in neonates and juveniles, but were in adults. Chital stags had higher erythrocyte parameters (P less than 0.001) and lower erythrocyte indices than hinds, and the total leucocyte count was higher in stags (P less than 0.01). Some parameters (erythrocytes, muscle enzymes, glucose, cortisol) decreased over successive serial sampling. The differential leucocyte count of older stags decreased during the initial handling period. The major rutting period in February and March was characterised by changes in the differential leucocyte count, elevations in serum muscle enzymes, and lower serum cortisol levels. Alkaline phosphatase activity in serum reflected the annual antler cycle of chital stags. Serial sampling over many weeks, either weekly or tri-weekly, produced haematological and biochemical changes in successive samples which may have reflected a reduction in stress and excitement associated with restraint.     

Total body haematocrit iron kinetics and erythrocyte life span in pigeons (Columba livia)

1. The mean pigeon erythrocyte life span was found to be 17-25 days by Cr51-labeled erythrocytes and 21 +/- 3.4 days by iron kinetics. 2. Total red blood cell volume has been calculated by Cr51-labeled erythrocytes while total plasma volume was determined both by a dye method and iron kinetic data. From these results total blood volume and total body haematocrit were found to be 0.090 +/- 0.002 ml/g body wt and 36 +/- 4.3%, respectively. 3. Venous haematocrit, haemoglobin concentration, erythrocyte count, mean corpuscular haemoglobin concentration, plasma iron and red blood cell iron have also been measured. 4. A significant difference between total body and venous haematocrit and a short mean red blood cell life span, due to ageing and to random destruction of erythrocytes were shown. 5. The above observations are compared with analogous available data for human beings and their physiological significance is discussed.     

Exercise-induced oxidative stress affects erythrocytes in sedentary rats but not exercise-trained rats.

Oxidant stress is one of the factors proposed to be responsible for damaged erythrocytes observed during and after exercise. The impact of exertional oxidant stress after acute exhaustive treadmill running on erythrocyte damage was investigated in sedentary (Sed) and exercise-trained (ET) rats treated with or without antioxidant vitamins C and E. Exhaustive exercise led to statistically significant increments in the levels of thiobarbituric acid-reactive substance (TBARS) and H2O2-induced TBARS in Sed rats and resulted in functional and structural alterations in erythrocytes (plasma hemoglobin concentrations, methemoglobin levels, and rise in osmotic fragility of erythrocytes with decrease in erythrocyte deformability). Administration of antioxidant vitamin for 1 mo before exhaustive exercises prevented lipid peroxidation (TBARS, H2O2-induced TBARS) in Sed rats without any functional or structural alterations in erythrocytes. Parameters indicating erythrocyte lipid peroxidation and deterioration after exhaustive exercise in rats trained regularly with treadmill running for 1 mo were not different from those in Sed controls. Erythrocyte lipid peroxidation (TBARS) increased in exhausted-ET rats compared with ET controls; however, the plasma hemoglobin, methemoglobin levels, and erythrocyte osmotic fragility and deformability did not differ. Exhaustive exercise-induced lipid peroxidation in ET rats on antioxidant vitamin treatment was prevented, whereas functional and structural parameters of erythrocytes were not different from those of the ET controls. We conclude that exertional oxidant stress contributed to erythrocyte deterioration due to exercise in Sed but not in ET rats.     

The haematology of triploid landlocked Atlantic salmon, Salmo solar L.

Triploid landlocked Atlantic salmon had a larger mean erythrocyte volume but lower erythrocyte count than diploids; the haematocrit was the same in diploids and triploids. Although the total blood haemoglobin content and the mean corpuscular haemoglobin concentration were lower in triploids than in diploids, the actual mean corpuscular haemoglobin content of triploid erythrocytes was higher than that of diploids. The increase in triploid mean erythrocyte volume was mainly due to an increase in cell length; there was only a minor increase in cell width and no increase in cell height. The nucleus of triploid erythrocytes occupied a greater percentage of the corpuscular volume than did the diploid nucleus. Mean cytoplasmic haemoglobin concentration was found to be the same for diploids and triploids when this was taken into account     

Eperythrozoon ovis: the difference in carbohydrate metabolism between infected and uninfected sheep erythrocytes.

The glucose utilization lactic and pyruvic acid production and oxygen uptake of normal and Eperythrozoon ovis infected sheep erythrocytes were measured under aerobic conditions. Infected cells showed marded increases in both glucose utilization and acid production as compared with controls. Uninfected erythocyte samples which included a percentage of reticulocytes comparable to that found in E. ovis infection showed no apparent difference in glucose utilization and lactic acid production form the normal control erythrocytes, although considerable increases in the oxygen uptake were recorded.     

Effect of vitamin E supplementation on post-exercise plasma lipid peroxidation and blood antioxidant status in smokers: with special reference to haemoconcentration effect

The oxidative effects were investigated of exhausting exercise in smokers, and the possible protective role of 400 mg day(-1) vitamin E (Vit E) supplementation over a period of 28 days. The subjects exercised to exhaustion including concentric-eccentric contractions following maximal cycling. The haematocrit and haemoglobin, leucocyte (WBC), plasma lactic acid (La) and malondialdehyde (MDA), erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx), serum Vit E and ceruloplasmin (CER) concentrations were measured pre and post exercise. Supplementation increased Vit E concentrations 28% and 31% in the controls and the smokers, respectively. Cigarette smoking and/or Vit E supplementation did not influence plasma lipid peroxidation or the antioxidant status at rest. Exercise caused significant haemoconcentration in all groups. When the post-exercise concentrations were adjusted for haemoconcentration, a significant elevation in La concentrations due to exercise was observed in all groups. Similarly, there were significant elevations in the adjusted WBC counts in all groups except the Vit E supplemented controls. The MDA concentrations on the other hand, when adjusted for haemoconcentration, did not exhibit any difference due to exercise. Exercise did not affect the GPx and CER activities either, while causing a SOD activity loss in all groups except the Vit E supplemented non-smokers. Serum Vit E concentrations diminished significantly in all groups after exercise. Post-exercise plasma MDA and blood antioxidant concentrations were not altered by smoking. The results would suggest that plasma volume changes should always be taken into account when assessing post-exercise plasma concentrations and that smoking and exercise do not have an additional collective effect on plasma lipid peroxidation and the dose of Vit E administered was insufficient to maintain the serum concentrations after exercise.     

Exercise training induces glycogen sparing during exercise by old rats

Glycogen utilization during exercise appears to be related to muscle respiratory capacity. Since the decline in hindlimb muscle respiratory capacity that occurs in rats during old age is eliminated when young and old rats undergo an identical exercise training protocol, liver and gastrocnemius glycogen concentrations were determined in identically trained young and old Fischer 344 rats at rest and immediately after a 30-min run requiring approximately 75% of maximal O2 consumption. These values were also compared with untrained age-matched control animals. The animals, which were 10 or 24 mo old after 6 mo of training, were fasted for 24 h before they were killed. Resting gastrocnemius glycogen did not differ among the groups. After 30 min of running, gastrocnemius glycogen was lower in the untrained than the trained groups and was not different between the trained groups. Resting liver glycogen was lower in the old trained group than the untrained groups but not statistically different from the young trained group. The postrun liver glycogen did not differ among the groups. Estimated gastrocnemius and liver glycogen utilization during exercise was decreased in both trained groups compared with untrained age-matched controls. These results indicate that the training-induced glycogen sparing during exercise of the same relative intensity was not diminished with age in identically trained young and old rats.     

Changes in the nucleotide triphosphate/haemoglobin and nucleotide triphosphate/red cell ratios of rainbow trout, Salmo gairdneri Richardson, subjected to prolonged starvation and bleeding

The nucleotide triphosphate/haemoglobin (NTP/Hb) and nucleotide triphosphate/red cell (NTP/cell) ratios of rainbow trout increased during prolonged starvation. A decline was noted in blood lactic acid concentration. Red cell count, haemoglobin concentration and haematocrit also declined. Changes in mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were found not to be significant. The NTP/Hb and NTP/cell ratios of both fed and starved trout rose seven days following a 15% reduction in blood volume by cardiac puncture. A rise in whole blood NTP concentration was found only in the bleeding response of fed animals. No significant change was noted in blood lactic acid concentration. The decline in haematocrit was significant only in the starved group. In both groups, however, red cell count and blood haemoglobin concentration fell. MCV rose whereas MCHC declined in all bled animals. Changes in MCH were not significant in either group. Negative correlations were noted between red cell count and both the NTP/Hb and NTP/cell ratios and between haemoglobin concentration and the NTP/Hb ratio. Positive correlations were seen between the two ratios and between red cell count and haemoglobin concentration.     

Some aspects of haematology of a common Indian field rat, Rattus rattus arborious (Linn.) in relation to sex and size.

In the present investigation the studies on erythrocyte and leucocyte counts, haemoglobin concentration, haematocrit values, blood biochemistry of protein, glucose and cholesterol, erythrocyte sedimentation rate, pH value, diameter of erythrocyte and clotting time were made in different sex and size (weight group) of an Indian field rat, Rattus rattus arborious. The number of erythrocyte, haemoglobin concentration, haematocrit values were found to be higher in females than the males, while the number of leucocyte was lower in females in comparison to males. In the biochemical estimation the value of protein in females was high while that of the glucose and cholesterol were lower than that of the males. All the above values showed an increasing tendency with the increase in body weight. pH value, diameter of erythrocyte and clotting time were found to be almost constant in rats of different weight groups and different sex.     

Differences between breeds of rabbits in their susceptibility to the effect of foschlor

The purpose of the study was to investigate the effect of foschlor on erythrocytes and leucocytes in two breeds of rabbits--Belgian and black-and-tan. Administration of the pesticide caused a considerable drop in the number of erythrocytes, haemoglobin level and haematocrit value in both breeds. Changes in the values of red blood cell indices, characterized by an increase in mean erythrocyte volume and haemoglobin content in blood cells, were observed in the black-and-tan breed only. The pesticide used caused changes in leucocytes in both breeds, expressed as a distinct neutrophilic leucocytosis with lymphopaenia and eosinopaenia. Changes in the leucogram were reflected in the increase in the leucocyte index. The degree of intensity of the changes in both erythrocytes and leucocytes points to the greater resistance of the Belgian breed to intoxication by foschlor than the black-and-tan breed.     

Hypoxic exercise training causes erythrocyte senescence and rheological dysfunction by depressed Gardos channel activity

Despite enhancing cardiopulmonary and muscular fitness, the effect of hypoxic exercise training (HE) on hemorheological regulation remains unclear. This study investigates how HE modulates erythrocyte rheological properties and further explores the underlying mechanisms in the hemorheological alterations. Twenty-four sedentary males were randomly divided into hypoxic (HE; n = 12) and normoxic (NE; n = 12) exercise training groups. The subjects were trained on 60% of maximum work rate under 15% (HE) or 21% (NE) O(2) condition for 30 min daily, 5 days weekly for 5 wk. The results demonstrated that HE 1) downregulated CD47 and CD147 expressions on erythrocytes, 2) decreased actin and spectrin contents in erythrocytes, 3) reduced erythrocyte deformability under shear flow, and 4) diminished erythrocyte volume changed by hypotonic stress. Treatment of erythrocytes with H(2)O(2) that mimicked in vivo prooxidative status resulted in the cell shrinkage, rigidity, and phosphatidylserine exposure, whereas HE enhanced the eryptotic responses to H(2)O(2). However, HE decreased the degrees of clotrimazole to blunt ionomycin-induced shrinkage, rigidity, and cytoskeleton breakdown of erythrocytes, referred to as Gardos effects. Reduced erythrocyte deformability by H(2)O(2) was inversely related to the erythrocyte Gardos effect on the rheological function. Conversely, NE intervention did not significantly change resting and exercise erythrocyte rheological properties. Therefore, we conclude that HE rather than NE reduces erythrocyte deformability and volume regulation, accompanied by an increase in the eryptotic response to oxidative stress. Simultaneously, this intervention depresses Gardos channel-modulated erythrocyte rheological functions. Results of this study provide further insight into erythrocyte senescence induced by HE.     

Effect of physical exercise on fibrinolytic properties of erythrocytes

The fibrinolytic properties of blood and erythrocytes were studied before and after physical exercise in male volunteers. Their fibrinolytic responses were of two distinct types. In type 1 response, fibrinolytic activities of blood and erythrocytes increased; the plasminogen activator and active plasmin contents in erythrocytes also increased, whereas the profibrinolysin content correspondingly decreased. In addition, physical exercise increased the erythrocyte adsorption properties for plasma activators of fibrinolysis. Type 2 response was characterized by a decrease in the fibrinolytic activity of blood; neither fibrinolytic activity nor adsorption properties of erythrocytes increased. The type of blood and erythrocyte response to muscular activity was determined by the pre-exercise level of red blood cell fibrinolytic activity. It was low in type 1 response due to a lesser content of plasmin activators and greater content of antiplasmin. In type 2 response, the initially high lytic capacity is connected with a greater reserve of activators and lesser reserve of inhibitors of the fibrinolytic system. A conclusion was made that individual differences in fibrinolytic responses to physical exercise were largely accounted for by the properties of erythrocytes.     

Glycemic index of a meal fed before exercise alters substrate use and glucose flux in exercising horses.

In a randomized, balanced, crossover study each of six fit, adult horses ran on a treadmill at 50% of maximal rate of oxygen consumption for 60 min after being denied access to food for 18 h and then 1) fed corn (51.4 kJ/kg digestible energy), or 2) fed an isocaloric amount of alfalfa 2-3 h before exercise, or 3) not fed before exercise. Feeding corn, compared with fasting, resulted in higher plasma glucose and serum insulin and lower serum nonesterified fatty acid concentrations before exercise (P < 0.05) and in lower plasma glucose, serum glycerol, and serum nonesterified fatty acid concentrations and higher skeletal muscle utilization of blood-borne glucose during exercise (P < 0.05). Feeding corn, compared with feeding alfalfa, resulted in higher carbohydrate oxidation and lower lipid oxidation during exercise (P < 0.05). Feeding a soluble carbohydrate-rich meal (corn) to horses before exercise results in increased muscle utilization of blood-borne glucose and carbohydrate oxidation and in decreased lipid oxidation compared with a meal of insoluble carbohydrate (alfalfa) or not feeding. Carbohydrate feedings did not produce a sparing of muscle glycogen compared with fasting.     

Effect of magnesium supplementation and training on magnesium tissue distribution in rats

The aim of this work is to study the effect of training and Mg supplementation on body pools of Mg and on Mg tissue distribution. Forty male Wistar rats were divided into four groups (n=10): control group (C); trained group (T); Mg-supplemented group (+Mg); and trained and Mg-supplemented group (+MgT). The Mg supplement (100 ppm of Mg) was given in the drinking water for 21 d. The training consisted of swimming during 60% of maximal swimming time obtained in the first session to exhaustion, during 3 wk (5 d a week). The variables measured were: erythrocytes (RBC), hemoglobin (Hb), hematocrit (Hto), total proteins (TP), and Mg in serum, RBC, liver, muscle, bone, and kidney. There was less Mg in liver, muscle, and erythrocyte in trained animals than in control or supplemented animals (T vs C, +MgT vs C and +MgT vs +Mg) (p < 0.01). Trained antimals (T and +MgT) showed higher Mg kidney rates than the untrained ones (p<0.01). There was less bone Mg in control (C) and in supplemented and trained (+MgT) groups than in trained (T) and in supplemented (+Mg) animals (p<0.01). Serum Mg showed a decreasing concentration profile in the following order: +Mg, +MgT, T, C (p<0.01). We conclude that Mg supplementation improves bone and serum Mg levels, but this does not affect Mg status in soft tissues. Maintained exercise leads to a diminution of Mg in the aforementioned soft tissues that is not noticeable in serum, probably provoked by an increase of renal excretion.     

Gender differences in substrate for endurance exercise

The effects of gender on substrate utilization during prolonged submaximal exercise were studied in six males and six equally trained females. After 3 days on a controlled diet (so that the proportions of carbohydrate, protein, and fat were identical), subjects ran on a treadmill at a velocity requiring an O2 consumption of approximately 65% of maximal. They ran a total "distance" of 15.5 km with a range in performance time of 90-101 min. Plasma glycerol, glucose, free fatty acids, and selected hormones (catecholamines, growth hormone, insulin, and glucagon) were measured throughout and after the run by sampling from an indwelling venous catheter, and glycogen utilization was calculated from pre- and postexercise needle biopsies of vastus lateralis. Exercise protein catabolism was estimated from 24-h urinary urea nitrogen excretion over the test day and a nonexercise day. The males were found to have significantly higher respiratory exchange ratios (mean 0.94 vs. 0.87), greater muscle glycogen utilization (by 25%), and greater urea nitrogen excretion (by 30%) than the females. No gender differences were evident in the hormonal response to the exercise with the exception of a lower insulin concentration and a higher epinephrine concentration in the males. We conclude that, during moderate-intensity long-duration exercise, females demonstrate greater lipid utilization and less carbohydrate and protein metabolism than equally trained and nourished males.     

Androgen Responses during Physical Exercise

The serum androgen response to physical exercise was studied in highly trained athletes and in normal male medical students. Serum androgens rose in response to maximal exercise and the rise was independent of serum luteinizing hormone. No response was obtained with submaximal exercise.     

Considerations of blood parameters of largemouth bass, Micropterus salmoides

To evaluate physiological stress resulting from environmental influences, a haematological study of a natural population of largemouth bass, Micropterus salmoides , was undertaken to establish a 'normal' blood profile. Several parameters including haemoglobin concentration, haematocrit, erythrocyte count, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, plasma protein concentration and glucose levels were investigated. Haematocrit, haemoglobin, and total plasma protein were positively correlated with fish length. Haemoglobin and haematocrit were positively correlated with fish age while mean corpuscular haemoglobin, concentration was negatively correlated with fish age. Both haemoglobin and haematocrit values were related to erythrocyte counts.