The effect of acute physical exercise on insulin sensitivity and responsiveness glucose uptake hepatic production was studied. Seven untrained men were subjected to four sequential euglycemic hyperinsulinemic clamps after rest (R), immediately (E), as well 48 h 60 min 150 W ergometer (ER). Insulin-mediated higher E ER days compared with R days. Apparent Km decreased (52 +/- 3 vs. 43 4 40 microU/ml, means SE) Vmax increased (9.5 0.8 10.9 0.7 10.7 mg.min-1.kg-1). Glucose oxidation the...

1. This study was performed to test the hypothesis that exercise-induced increase in circulating cytokine levels is associated with muscle damage. Nine healthy young male subjects two high-intensity bicycle exercise trials separated by weeks. The first trial consisted of 30 min normal (concentric exercise), whereas second braking reversed revolution (eccentric exercise). work loads were chosen give same increases heart rate and catecholamine blood during each trial. 2. Significant (P < 0.05)...

Eight men were studied during graded (47, 77, and 100% of maximal oxygen uptake) prolonged (76%) exhaustive treadmill running. During exercise the glucagon concentration increased 35% from 81 plus or minus 7 pg/ml (mean SE) at rest to 109 17 after heaviest load. progressively three times (226 40) resting value. Norepinephrine 0.40 0.06 ng/ml 2.22 0.39, epinephrine 0.07 0.01 0.42 0.13 graded, 1.51 0.08 0.33 0.04, respectively, exercise. Insulin concentrations depressed work except for Fatty...

The effect of 1 h dynamic one-legged exercise on insulin action in human muscle was studied 6 healthy young men. Four hours after knee extensions, a three-step sequential euglycemic hyperinsulinemic clamp combined with arterial and bilateral femoral vein catheterization performed. Increased glucose uptake found the exercised compared rested thigh at mean plasma concentrations 23, 40, 410 microU/ml. Furthermore, prior contractions directed toward glycogen synthesis increased effects O2...

Physical training increases insulin action in skeletal muscle healthy men. In non-insulin-dependent diabetes mellitus (NIDDM), only minor improvements whole-body are seen. We studied the effect of on insulin-mediated glucose clearance rates (GCRs) whole body and leg seven patients with NIDDM eight control subjects. One-legged was performed for 10 weeks. GCR both legs were measured before, day after, 6 days after by hyperinsulinemic (28, 88, 480 mU · min−1 m−2), isoglycemic clamps combined...

The importance of carbohydrate availability during exercise for metabolism and plasma hormone levels was studied. Seven healthy men ran on a treadmill at 70% individual maximal oxygen uptake having eaten diet low (F) or high (CH) in through 4 days. At exhaustion the subjects were encouraged to continue run while glucose infusion increased preexercise levels. Forearm venous blood, biopsies from vastus muscle expiratory gas analyzed. Time longer CH- (106 +/- 5 min (S.E.)) than F-expts. (64 6)....

Patients with non-insulin-dependent diabetes mellitus (NIDDM) exhibit insulin resistance and decreased glucose transport in skeletal muscle. Total content of muscle GLUT4 protein is not affected by NIDDM, whereas mRNA reported, variously, to be unaffected or increased. Physical training recommended the treatment but effect on unknown. To clarify seven men NIDDM (58 ± 2 years age [mean SE]) eight healthy (59 1 age) (control group) performed one-legged ergometer bicycle for 9 weeks, 6...

During insulin stimulation whole body glucose uptake is increased in trained compared with untrained humans. However, it not known which tissue responsible. Seven young male subjects bicycle one leg for 10 wk at 70% of maximal O2 consumption (VO2max). Sixteen hours after last exercise bout, a three-step euglycemic hyperinsulinemic clamp (clamp 1) was performed (insulin levels, means +/- SE: 9 1, 53 3, 174 5, and 2,323 80 microU/ml), measurement arteriovenous differences blood flow both legs....

The effect of 10 wk endurance swim training on 3-O-methylglucose (3-MG) uptake (at 40 mM 3-MG) in skeletal muscle was studied the perfused rat hindquarter. Training resulted an increase approximately 33% for maximum insulin-stimulated 3-MG transport fast-twitch red fibers and contraction-stimulated slow-twitch compared with nonexercised sedentary muscle. A fully additive insulin contractions observed both trained untrained Compared control rats subjected to almost exhaustive single exercise...

Exposure to altitude hypoxia elicits changes in glucose homeostasis with increases and insulin concentrations within the first few days at altitude. Both increased unchanged hepatic production (HGP) have previously been reported response acute hypoxia. Insulin action on uptake has never investigated during In eight healthy, sea level resident men (27 ± 1 years (mean S.E.M.); weight, 72 2 kg; height, 182 cm) hyperinsulinaemic (50 mU min −1 m −2 ), euglycaemic clamps were carried out level,...

1. The release of vasoactive intestinal polypeptide from the gastrointestinal tract in response to stimulation vagus nerves, splanchnic nerves and intra-arterial infusion acetylcholine (ACh) was examined pigs. 2. Stimulation caused an abrupt increase polypeptide. amount peptide released depended on frequency at which were stimulated. Maximum obtained 8 Hz. 3. Atropine beta-adrenergic blocking agents failed diminish vagally induced polypeptide, while completely blocked by hexamethonium...

In this study, the hypothesis that release of interleukin (IL)‐6 from human muscle is linked to exercise intensity and glucose uptake was investigated. overnight fasted state, seven healthy males performed knee extension exercise, kicking with both legs, each at 25 % maximal power ( W max ) for 45 min (eliciting 23 ± 1 pulmonary oxygen uptake, V̇ O2,max then simultaneously one leg 65 other 85 35 (40 ). Blood sampled a femoral artery veins, blood flow determined by thermodilution. Thigh...

We reinvestigated the prevailing concept that muscle contractions only elicit increased glucose uptake in presence of a so-called “permissive” concentration insulin (Berger et al., Biochem. J. 146: 231–238, 1975; Vranic and Berger, Diabetes 28: 147–163, 1979). Hindquarters from rats severe ketoacidosis were perfused with perfusate containing antiserum. After 60 min perfusion, electrical stimulation contracting muscles fivefold. Also, subsequent hindquarters nondiabetic for 1.5 h...

The present study was designed to test the hypothesis that changes in natural killer (NK) cell activity response physical exercise were mediated by increased epinephrine concentrations. Eight healthy volunteers 1) exercised on a bicycle ergometer (60 min, 75% of maximal O2 uptake) and 2) later day given as an intravenous infusion obtain plasma concentrations comparable with those seen during exercise. Blood samples collected basal state, last minutes or infusion, 2 h later. NK (lysis/fixed...

The interaction of epinephrine and contractions on muscle metabolism was studied in the isolated perfused rat hindquarter. Subtetanic (180/min) through 20 min elicited glycogenolysis increased phosphorylase a activity. In soleus, slow-twitch red muscle, these effects were transient, but when at physiological concentration (2.4 X 10(-8) M) added to perfusate, activity sustained throughout contractions. At this high frequency contractions, effect much smaller fast-twitch fibers not significant...

Epinephrine responses to insulin-induced hypoglycemia have indicated that athletes a higher adrenal medullary secretory capacity than untrained subjects. This view was tested by an exercise protocol aiming at identical stimulation of the medulla in two groups. Eight (T) and eight controls (C) ran 7 min 60% maximal O2 consumption (VO2max), 3 100% VO2max, 2 110% VO2max. Plasma epinephrine both rest relative work loads [110% VO2max: 8.73 +/- 1.51 vs. 3.60 1.09 mmol X l-1 (C)] [P less 0.05) T C....

In healthy young subjects, training increases insulin sensitivity but decreases the capacity to secrete insulin. We studied whether changes beta-cell function in type 2 diabetic patients. Patients, stratified into "moderate" and "low" secretors according individual C-peptide responses an intravenous glucagon test, were randomly assigned a program [ergometer cycling 30-40 min/day, including at least 20 min 75% maximum oxygen consumption (Vo(2 max)), 5 days/wk for 3 mo] or sedentary schedule....

1. Physical training enhances sensitivity and responsiveness of insulin-mediated glucose uptake in human muscle. This study examines if this effect physical is due to increased insulin receptor function or total concentration insulin-recruitable transporter protein (GLUT 4). 2. Seven healthy young subjects carried out single leg bicycle for 10 weeks at 70% one maximal oxygen (VO2,max). Subsequently biopsies were taken from the vastus lateralis muscle both legs. 3. Single VO2,max trained (46...

Seven men ran at 60% of individual maximal oxygen uptake to exhaustion during beta-adrenergic blockade with propranolol (P), lipolytic nicotinic acid (N), or without drugs (C). The total work times (83 +/- 9 122 8 166 10 (C) min, mean and SE) differed significantly. Epinephrine rose progressively above preexercise levels (0.06 0.01 ng/ml); concentrations in P experiments (2.15 0.41) were larger than N (1.08 0.31) C (0.72 0.28) experiments. Norepinephrine increased consistently while insulin...

Maximal dynamic exercise results in a postexercise hyperglycemia healthy young subjects. We investigated the influence of maximal on glucoregulation non-insulin-dependent diabetic subjects (NIDDM). Seven NIDDM and seven control males bicycled 7 min at 60% their O2 consumption (VO2max), 3 100% VO2max, 2 110% VO2max. In both groups, glucose production (Ra) increased more with than did uptake (Rd) and, accordingly, plasma increased. However, increase Ra was hastened Rd inhibited compared...