Precursors to glycogen in ovine fetuses

Journal Article · Tue Nov 01 04:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:6252653

Levitsky, L L; Paton, J B; Fisher, D E ^[1]

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1. Univ. of Chicago, IL (USA)

Postprandial hepatic glycogenesis in the adult animal is now felt to proceed largely through gluconeogenic pathways rather than directly from glucose. The ovine fetus, like the mature sheep, lacks specific hepatic glucokinase. Therefore, the authors examined the role of lactate as a fetal glycogenic precursor in seven chronically catheterized 125-day sheep fetuses. Fetuses were infused with L-(U-{sup 14}C)lactate and D-(3-{sup 3}H)glucose, while maternal glucose was maintained at 50 mg/dl. Mean fetal hepatic glycogen specific activity ({mu}Ci/mg {times} 10{sup 3}) was 0.82 {plus minus} 0.08 for {sup 14}C and 2.6 {plus minus} 0.4 for {sup 3}H, whereas fetal renal glycogen specific activity was 0.46 {plus minus} 0.22 for {sup 14}C and 0.78 {plus minus} 0.16 for {sup 3}H. In contrast, ({sup 14}C)glucose specific activity was undetectable in blood and mean ({sup 3}H)glucose specific activity was 8.9 {plus minus} 1.3 {mu}Ci/mg {times} 10{sup 3}. The least detectable specific activity of ({sup 14}C)glucose did not differ significantly from the ({sup 14}C)glycogen enrichment in liver, whereas ({sup 3}H)glucose specific activity was significantly greater than ({sup 3}H)glycogen enrichment. The authors conclude that glycogenesis from glucose is partly through the indirect gluconeogenic route and that lactate may be a glycogenic precursor in the ovine fetus.

• OSTI ID: 6252653
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 255:5; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ANIMALS
BIOLOGICAL PATHWAYS
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
DIGESTIVE SYSTEM
DOMESTIC ANIMALS
ENZYMES
FETUSES
GLANDS
GLUCOSE
GLYCOGEN
HEXOSES
HYDROGEN COMPOUNDS
HYDROXY ACIDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LACTIC ACID
LIVER
MAMMALS
METABOLISM
MONOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PHYSIOLOGY
POLYSACCHARIDES
PREGNANCY
RUMINANTS
SACCHARIDES
SHEEP
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS
VERTEBRATES