Beneficial effect of short-term endurance training on glucose metabolism during rehabilitation after coronary bypass surgery.

AIMS: Our study was aimed at determining whether beneficial modification of carbohydrate metabolism can be obtained after a short-term training program and whether it is associated with an increase in binding and degradation of (125)I-insulin by erythrocyte receptors that suggests a decrease in insulin resistance. METHODS: The study was conducted in a group of 20 patients aged 56 +/- 1.9 years (mean +/- SEM), within 1 to 6 months after coronary bypass surgery. All patients completed 15 training sessions based on 30 min of cycling with a constant load. Before and after a 3-week training program, glucose, insulin, and C-peptide blood levels, as well as binding and degradation of (125)I-insulin by erythrocyte receptors, were determined. RESULTS: A statistically significant decrease was found in the blood glucose level, from 111.2 +/- 4.2 to 97.8 +/- 3.5 mg/dL (p < 0.01); this decrease was not accompanied by significant insulin concentration changes. There was also a significant increase in insulin binding, from 0.535 +/- 0.059 to 0.668 +/- 0.042 pg (125)I/10(11) RBCs (p < 0.01), and degradation from 7.64 +/- 0.54 to 9.49 +/- 0.58 pg (125)I/10(11) RBCs (p < 0.05). CONCLUSION: The results indicated that even short-term endurance training in patients rehabilitated after coronary bypass surgery induced favorable modification of glucose metabolism, presumably caused by a decrease in insulin resistance.

The influence of short-term endurance training on the insulin blood level, binding, and degradation of 125I-insulin by erythrocyte receptors in patients after myocardial infarction.

PURPOSE: This study was directed toward establishing whether and to what extent, short-term endurance training influences the insulin blood level, and the binding and degradation of 125I-insulin by erythrocyte receptors in patients undergoing rehabilitation after myocardial infarction. METHODS: The study was conducted in a group of 60 patients who had had myocardial infarction within the past 1.5 to 3 months and who did not have arterial hypertension and diabetes mellitus. All the patients took a symptom-limited cardiopulmonary exercise test. Before and after the test, venous blood was collected to determine lactic acid and insulin blood levels as well as the binding and degradation of 125I-insulin. The study group was randomized into two subgroups. One subgroup entered into a 3-week in-patient rehabilitation course. The control group was discharged from the hospital and was given no recommendations for physical exercise. The same investigation was repeated 3 weeks later. RESULTS: In the patients (50%) with hyperinsulinemia (insulin resistance index, > 10 microIU/mL), which was detected during the first investigation, insulin blood level decreased from 23.9 +/- 4.4 to 15.0 +/- 1.9 microIU/mL (P < 0.05) after rehabilitation, whereas insulin binding increased from 0.67 +/- 0.05 to 0.85 +/- 0.08 pg 125I/10(11) erythrocytes (P < 0.05). In the control group, which included normal subjects and those with hyperinsulinemia, the results obtained during the first and second investigations showed no statistically significant changes when compared. CONCLUSIONS: The results suggest that a 3-week endurance training period during rehabilitation after myocardial infarction reduces insulin resistance in patients with hyperinsulinemia.

[Insulin binding to erythrocyte receptors in patients with essential hypertension]. / Wiazanie insuliny przez receptory insulinowe erytrocytów chorych na nadcisnienie tetnicze pierwotne.

Recently many researchers have described the presence of insulin resistance and hyperinsulinemia in a substantial number of patients with essential hypertension. Reduced insulin binding to the receptors may play important role in development of insulin resistance in these patients. The study was aimed to assess the value of insulin binding to erythrocyte receptors in the patients with essential hypertension and compare to values in healthy persons. Additional purpose was the evaluation of insulin degradation by erythrocytes in patients with essential hypertension. 23 patients with essential hypertension (BMI 22.7 +/- 3.2) and 21 healthy persons (with BMI value 23.3 +/- 2.9) were studied. In all examined individuals the blood glucose and blood insulin concentrations were determined, insulin binding to erythrocyte receptors and insulin degradation by erythrocytes were measured by the method of Gambhir and al. Insulin concentration was significantly higher in patients with essential hypertension than in healthy subjects. We demonstrated a statistically significant positive correlation between body weight and insulin concentration in blood serum only in healthy people. Insulin binding to the receptors of red blood cells was significantly stronger (p < 0.001) in healthy persons than in patients with essential hypertension (0.972 +/- 0.395 pg 10(11) RBC and 0.446 +/- 0.14 pg 10(11) RBC respectively). In patients with hypertension insulin binding to receptors of red blood cells does not depend on body weight and insulin concentration in blood serum. Values of insulin degradation by erythrocyte in patients with essential hypertension and healthy persons were not significantly different. It seems that decreased insulin binding to insulin receptors is an important mechanism of insulin resistance patients with essential hypertension.

The influence of exercise-induced oxidative stress on binding and degradation of 125I-insulin by the receptors on erythrocytes.

In the present work we investigated the influence of oxidative stress induced by strenuous exercise on the affinity of a specific insulin receptors on human erythrocytes. 13 male members of the national basketball staff performed a maximal treadmill exercise test. In the blood samples collected before and directly after the test acid-base equilibrium parameters, lactic acid concentrations, glucose and insulin serum levels as well as 125I-insulin binding and degradation by receptor on erythrocytes were measured. As markers of oxidative stress, plasma thiobarbituric acid-reactive substance levels (TBARS) and red blood cells glutathione content (GSH) were determined. After the exercise test TBARS levels increased significantly and GSH concentrations decreased indicating that oxidative stress occurred. Binding of 125I-insulin to the receptors on erythrocytes decreased significantly during the test, while there was only insignificant reduction in 125I-insulin degradation. Correlation analysis and multiple linear regression revealed that changes in insulin degradation by receptors on erythrocytes during exhaustive exercise are determined by oxidative stress, probably via oxidation of sulfhydryl groups of certain enzymes. The affinity of receptors for insulin seems to depend mainly on glucose concentrations.

Glucosamine in serum of patients after myocardial infarction subjected to rehabilitation training.

This paper presents results of 3 weeks physical training on glucosamine level in serum of male patients after myocardial infarction (MI) aged between 38 and 61. Patients were randomised in two groups: the training group (n = 21), staying in Cardiac Rehabilitation Department and the control group (n = 11), discharged home for 3 weeks. Each group received identical dietary instructions. The training group performed exercises every day: on bicycle ergometer during 30 minutes (5 times a week), overall-conditioning exercises for 30 minutes daily and 30 to 60 minutes of walking each day. Before administering of the therapy and 3 weeks later all MI patients performed the bicycle ergometer exercise test until the ventilatory threshold was reached. Before that test and 3 minutes after its termination capillary and venous blood samples were drawn. In the capillary blood samples indices of acid-base balance, lactate level, and glucose level were determined. In venous blood samples the serum levels of immunoreactive insulin, C-peptide and glucosamine were determined as well as binding of 125I-insulin to erythrocyte receptors. Obtained results show that administered therapy increased physical fitness and decreased of glucosamine concentration, insulinaemia and insulin resistance.

Exercise-induced increase in hydrogen peroxide plasma levels is diminished by endurance training after myocardial infarction.

We have investigated the influence of physical training on exercise-induced changes in free radical activity in patients after myocardial infarction. Seventeen patients admitted to the cardiac rehabilitation center performed a bicycle ergometry before and after a 3-week endurance training program. The oxygen consumption and carbon dioxide production were measured and the ECG and the systemic blood pressure were monitored during the tests. Blood samples for acid-base equilibrium, lactic acid levels and hydrogen peroxide concentrations were collected directly before and after each exercise test. Exercise-induced increases in systolic blood pressure, heart rate and rate-pressure product as well as lactic acid concentrations were significantly less marked during the bicycle ergometry performed after the rehabilitation program. During the initial exercise test hydrogen peroxide levels increased significantly from 7.15+/-0.74 micromol/l before to 9.09+/-1.04 micromol/l 3 min after the test (P=0.0229). In contrast, no significant changes in hydrogen peroxide concentrations were observed during the exercise test performed after the training (6.31+/-1.05 micromol/l before the test, 5.85+/-1.08 micromol/l after the test, P=0.201). These observations suggest that physical training may have a beneficial influence on free radicals' generation in patients after myocardial infarction.

Glucosamine levels in people with ischaemic heart disease with and without type II diabetes.

Glucosamine has a major influence on the impairment of some metabolic mechanisms in the human body. As shown in vitro experiments, it takes part in inducing mechanisms of insulin resistance. Therefore, the purpose of our study was to evaluate glucosamine levels in the serum of patients who suffered myocardial infarction (MI) and who either had or didn't have diagnosed type II diabetes in relation to healthy people. The levels of glucosamine, immunoreactive insulin, C-peptide, glucose and lipid indexes were measured in venous blood in investigated patients. In patients with MI without diabetes the highest concentrations of glucosamine, insulin and C-peptide were noted as compared to the results obtained from other groups of patients. In patients with diabetes, on the other hand, the highest glucose levels were noted as compared to the results of other patients. There were no statistically differences of lipid indexes between two groups of patients following MI. A negative correlation between glucosamine levels and glucose concentrations in patients without diabetes may suggest that glucose does not directly determine glucosamine levels. The returning of insulin levels to normal in patients with hyperinsulinemia (antidiabetic drugs) may play a role in the lowering of glucosamine induced peripheral insulin resistance.

The influence of oral glucose intake on binding and degradation of 125I-insulin by receptors on erythrocytes as well as on insulin and C-peptide serum levels in patients after myocardial infarction and healthy individuals.

In this study, we investigated the influence of glucose administration on binding and degradation of 125I-insulin by receptors on erythrocytes as well as on insulin and C-peptide serum levels in 15 patients after myocardial infarction and in 15 age-matched healthy persons. Venous blood samples were taken directly before and at 30, 60 and 120 minutes after oral administration of 75 g of glucose. In the collected blood samples serum glucose, insulin and C-peptide levels were determined. Binding and degradation of 125I-insulin by specific receptors on red blood cells were evaluated using the method described by Gambhir and modified by the authors. Serum insulin and C-peptide levels were significantly higher while binding of 125I-insulin to erythrocytes was decreased in patients after myocardial infarction. These results seem to support the hypothesis that insulin resistance and hyperinsulinism play a role in the pathogenesis of ischaemic heart disease. Impaired degradation of 125I-insulin during the oral glucose tolerance test in the patients after myocardial infarction indicates that insulin resistance is located at the receptor level.

[Complex evaluation of body reaction in obese boys boys with systematic physical exertion and a low energy diet]. / Kompleksowa ocena reakcji organizmu otylych chlopców na systematyczny wysilek fizyczny skojarzony z dieta niskoenergetyczna.

This paper presents the results of researched influence of systematic physical effort together with a calorie restricted diet on fourteen-year-old obese boys. We evaluated their physical efficiency (VO2max), body consistency, blood lipid profile the level of non-enzymatic glycosylation of protein, insulinemia, and insulin resistance measured by the binding of 125I-Insulin to erythrocyte receptors. For 21 days, subjects performed 30 minutes of physical effort on a bicycle ergometer with load of 1 W/kg of body mass. Simultaneously, they were subjected to a calorie restricted diet at an average level of 1300 kcal. Before administering of the therapy and following its completion, the maximal amount of oxygen intake and body consistency was determined. Following that, the boy subjects performed an effort on the bicycle ergometer having an intensity of 70% VO2max and, simultaneously, capillary and venous blood was drawn for testing. In the capillary blood samples indices of acid-base balance, the lactate level, and glucose level were determined. In the venous blood samples levels of lipids, immunoreactive insulin, C-peptide and fructosamine were determined. Binding of 125I-Insulin was determined according to the method described by Gambhir and modified by us. Obtained results show that the administered therapy contributed to an increased physical efficiency, a decrease in the body's fatty mass, a reduction by 20% of insulinemia (p < 0.01) and insulin resistance as measured by the amount of 125I-Insulin binding.

Result of oral intake of glucose by healthy subjects and patients with essential hypertension on the binding and degradation of 125I-insulin by erythrocyte receptors.

The work presents the results of researches of binding and degradation of 125I-Insulin by erythrocyte receptors in the patients with essential hypertension and healthy patients after glucose intake. In order to obtain full representation of the pattern of changes the serum IRI and glucose concentrations were assayed. Binding and degradation of 125I-Insulin by erythrocyte receptors were determined with the method described by Gambhir (1977), modified by the authors. The modification consisted in usage of constant concentrations of iodized insulin (0.9 pg/0.1 ml) and bovine insulin (2.4 I.U./0.1 ml). Before administration of glucose and in 30, 60 and 120 minutes after, venous blood was collected from ulnar vein. All examined persons were in sitting position during the trial of glucose intake. Obtained results show, that blood insulin level in the patients with essential hypertension is statistically significantly higher than in healthy persons of similar anthropometric characteristics. Binding of 125I-Insulin to erythrocyte receptors in fasting state is statistically significantly lower. Degradation after glucose intake in the patients shows decreasing tendency, while in healthy persons--growing tendency.

[Fructosamine in blood serum, binding and degradation of 125J-insulin by erythrocyte receptors in young persons with type I diabetes--effect of physical exercise]. / Fruktozamina w surowicy krwi oraz wiazanie i degradacja 125J-insuliny przez receptory erytrocytów u mlodych osób z cukrzyca I typu--wplyw wysilku fizycznego.

The aim of investigation was the determination of the effect of regular physical exercise of intensity 35% VO2max on glycolysation of proteins, expressed by fructosamine concentration in blood serum and on insulin sensitivity of erythrocyte receptors in children with diabetes mellitus type I. The investigations were performed with 10 young persons with diabetes mellitus type I, during their sanatorium treatment. During 21 days the children effected every day a 20-minutes ergometric exercise of intensity equivalent approximately to 35% VO2max. Before the 3-weeks therapy and after its termination the examined children have performed an ergometric test exercise, with collection of blood samples. Obtained results allow to ascertain, that regular aerobic exercise contributed to the growth of physical efficiency expressed by the VO2max value, reduction in fructosamine level in blood serum, increase in insulin sensitivity of erythrocyte receptor and improved effort tolerance related to glycemia.

[Activity of pyrimidine 5'nucleotidase (py5'Nd) of erythrocytes in essential hypertension]. / Aktywnosc nukleotydazy 5'pirymidynowej (Py5'Nd) krwinek czerwonych w nadcisnieniu tetniczym pierwotnym.

Activity of pyrimidine 5'nucleotidase was measured in hemolysate of erythrocytes of healthy persons and patients with essential hypertension. Cytidine 5'monophosphate (CMP) and uridine 5'monophosphate (UMP) were used as the substrates for evaluation of activity of so called I-isoenzyme and uridine 3'monophosphate (U3'MP) was used as a substrate for the II isoenzyme of Py5'Nd. It was found that the activity of Py5'Nd I was lower in hypertensives (26.8 mU/gHb (CMP)) and 69.3 mU/gHb (UMP) in comparison with normotensives (62.3 and 117.4 mU/gHb respectively) (p < 0.05). The activity of Py5'Nd II did not differ between studied groups. Possible metabolic consequences of decreased activity of Py5'Nd are discussed.