title: Prior exercise and postprandial substrate extraction across the human leg.
abstract: Prior exercise decreases postprandial plasma triacylglycerol (TG) concentrations, possibly through changes to skeletal muscle TG extraction. We measured postprandial substrate extraction across the leg in eight normolipidemic men aged 21-46 yr. On the afternoon preceding one trial, subjects ran for 2 h at 64 +/- 1% of maximal oxygen uptake (exercise); before the control trial, subjects had refrained from exercise. Samples of femoral arterial and venous blood were obtained, and leg blood flow was measured in the fasting state and for 6 h after a meal (1.2 g fat, 1.2 g carbohydrate/kg body mass). Prior exercise increased time averaged postprandial TG clearance across the leg (total TG: control, 0.079 +/- 0.014 ml.100 ml tissue(-1).min(-1) ; exercise, 0.158 +/- 0.023 ml.100 ml tissue(-1).min(-1), P <0.01), particularly in the chylomicron fraction, so that absolute TG uptake was maintained despite lower plasma TG concentrations (control, 1.53 +/- 0.13 mmol/l; exercise, 1.01 +/- 0.16 mmol/l, P < 0.001). Prior exercise increased postprandial leg blood flow and glucose uptake (both P < 0.05). Mechanisms other than increased leg TG uptake must account for the effect of prior exercise on postprandial lipemia.
authors.affiliation: Human Muscle Metabolism Research Group, Department of Physical Education, Sports Science and Recreation Management, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom.
authors.forename: D
authors.initials: D
authors.lastname: Malkova
authors.forename: R D
authors.initials: RD
authors.lastname: Evans
authors.forename: K N
authors.initials: KN
authors.lastname: Frayn
authors.forename: S M
authors.initials: SM
authors.lastname: Humphreys
authors.forename: P R
authors.initials: PR
authors.lastname: Jones
authors.forename: A E
authors.initials: AE
authors.lastname: Hardman
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood; D000328:Adult; D001783:Blood Flow Velocity; D001786:Blood Glucose / Q000378:metabolism; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005263:Femoral Artery; D005268:Femoral Vein; D005502:Food; D006801:Humans; D007328:Insulin / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D007866:Leg / Q000098:blood supply*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption; D012420:Running; D014280:Triglycerides / Q000097:blood*; D014655:Vascular Resistance
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D014280:Triglycerides; D019344:Lactic Acid; D020155:3-Hydroxybutyric Acid