Glucose kinetics in gluconeogenesis-inhibited rats during rest and exercise

Journal Article · Mon Jan 01 00:00:00 EST 1990 · American Journal of Physiology; (USA)

OSTI ID:6994546

Turcotte, L P; Rovner, A S; Roark, R R; Brooks, G A ^[1]

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1. Univ. of California, Berkeley (USA)

To evaluate the role played by gluconeogenesis in blood glucose homeostasis, female Sprague-Dawley rats were injected with mercaptopicolinic acid (MPA), a gluconeogenic inhibitor. Glucose kinetics were assessed by primed, continuous infusion of (U-14C)- and (6(-3)H)glucose via an indwelling jugular catheter at rest and during submaximal exercise at 13.4 m/min on level grade. Blood samples were taken from carotid catheters and analyzed for glucose and lactate concentrations and specific activities. Tissue glycogen samples were obtained from rats after exercise as well as from unexercised animals. When compared with the sham-injected animals, MPA-treated animals had 22% lower (5.92 +/- 0.36 vs. 7.62 +/- 0.21 mM) and 44% higher (1.90 +/- 0.11 vs. 1.32 +/- 0.09 mM) resting arterial glucose and lactate concentrations, respectively. Resting glucose appearance (Ra) rates were 20% lower in the MPA-treated animals (57.2 +/- 7.5 mumol.kg-1.min-1) than in the sham-injected animals (71.1 +/- 12.1 mumol.kg-1.min-1). During exercise, Ra increased to 174.7 +/- 32.8 mumol.kg-1.min-1 in sham-injected animals. In the MPA-treated animals, there was a 35% increase during the first 15 min of exercise, followed by a decrease to the resting values. MPA-treated animals had no measurable glucose recycling at rest or during exercise. Exercise decreased blood glucose concentration (35%) and increased blood lactate concentration (160%) in the MPA-treated animals. Exercising sham-injected animals had increased blood glucose (9.8%) but no change in blood lactate concentration. Moderate depletions in liver and skeletal muscle glycogen contents were observed after exercise.

• OSTI ID: 6994546
• Journal Information: American Journal of Physiology; (USA), Vol. 258; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GLUCOSE
METABOLISM
LACTATES
BIOSYNTHESIS
CARBON 14 COMPOUNDS
ENZYME INHIBITORS
EXERCISE
GLYCOGEN
HEART
HOMEOSTASIS
INHIBITION
ISOTOPE DILUTION
LIVER
MUSCLES
MYOCARDIUM
RATS
TRITIUM COMPOUNDS
ALDEHYDES
ANIMALS
BODY
CARBOHYDRATES
CARBOXYLIC ACID SALTS
CARDIOVASCULAR SYSTEM
DIGESTIVE SYSTEM
GLANDS
HEXOSES
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MONOSACCHARIDES
ORGANIC COMPOUNDS
ORGANS
POLYSACCHARIDES
RODENTS
SACCHARIDES
SYNTHESIS
TRACER TECHNIQUES
VERTEBRATES
550501* - Metabolism- Tracer Techniques