Epinephrine-induced changes in muscle carbohydrate metabolism during exercise in male subjects

induced changes in muscle carbohydrate metabolism during ex-ercise in maze subjects. J. Appl. Physiol. 60(5): 1466-1470, 1986.-Epinephrine increases glycogenolysis in resting skeletal muscle, but less is known about the effects of epinephrine on exercising muscle. To study this, epinephrine was given intra-arterially to one leg during two-legged cycle exercise in nine healthy males. The epinephrine-stimulated (EPI) and non-stimulated (C) legs were compared with regard to glycogen, glucose, glucose 6-phosphate (G6P), cu-glycerophosphate (CU-GP), and lactate contents in muscle biopsies taken before and after the 45min submaximal exercise, as well as brachial arterial-femoral venous (a-fv) differences for epinephrine, nor-epinephrine, lactate, glucose, and O2 during exercise. During exercise the arterial plasma epinephrine concentration was 4.8 t- 0.8 nmol/l and the femoral venous epinephrine concentra-tions were 10.3 t 2.1 and 3.9 t 0.6 nmol/l, respectively, in the EPI and C leg. During exercise the a-fv difference for lactate was greater (-0.41 t 0.14 vs.-0.21 t 0.14 mmol/l; P < O.OOl), and the a-fv difference for glucose was smaller (0.07 t 0.12 vs. 0.24 t 0.12 mmol/l; P < 0.01) in the EPI than in the C leg, but the a-fv differences for O2 were similar. Muscle glycoge