Abstract

Eight men were studied during graded (47, 77, and 100 of maximal oxygen uptake) and prolonged (76) exhaustive treadmill running. During graded exercisethe glucagon concentration increased 35 from 81 +/- 7 pg/ml (mean and SE) at rest to 109+/-17 after the heaviest load. During prolonged exercise glucagon increased progressively to three times (226+/-40) the resting value. Norepinephrine increased from 0.40+/-0.06 ng/ml to 2.22+/-0.39, epinephrine from 0.07/-0.01 to 0,42+/-0.13 during graded, and to 1.51+/-0.08 and 0.33+/-0.04, respectively, during prolonged exercise. Insulin concentrations were depressedduring work except for the heaviest load. Fatty acids rose throughout prolonged exercise, whereas blood glucose significantly diminished 30 min afterward.Glucagon concentrations correlated significantly with norepinephrine and epinephrine concentrations during prolonged and with epinephrine during gradedexercise. Although increments in catecholamines were similar, the glucagon secretion was larger during prolonged than during graded exercise. While increments in catecholamines might explain increased glucagon secretion during graded exercise, they cannot account completely for the rise of glucagon during prolonged exercise. Verf.-Referat