Glucose and ketone body turnover in fasting grey seal pups

• Published in: Acta physiologica Scandinavica 1991-04, Vol.141 (4), p.565-571
• Main Authors: Nordøy, E. S., Blix, A. S.
• Format: Article
• Language: English
• Subjects: acetoacetate; Animals; Biological and medical sciences; Blood Glucose - metabolism; Fasting - metabolism; Fatty Acids, Nonesterified - blood; Female; Fundamental and applied biological sciences. Psychology; gluconeogenesis; Glucose - metabolism; Glycosuria - metabolism; Halichoerus grypus; Hydroxybutyrates - blood; Intermediate and energetic metabolism; ketogenesis; Ketone Bodies - metabolism; Male; Metabolisms and neurohumoral controls; pinnipeds; Seals, Earless - metabolism; starvation; Vertebrates: anatomy and physiology, studies on body, several organs or systems; β-hydroxybutyrate
• ISSN: 0001-6772; 1365-201X
• DOI: 10.1111/j.1748-1716.1991.tb09118.x

Concentration and metabolic replacement (turnover) rate of glucose and ketone bodies were determined at intervals during a 52 day postweaning fast in five grey seal (Halichoerus grypus) pups, using bolus injections of radiotracers. Blood glucose was maintained at a high level throughout the fast, while β‐hydroxybutyrate increased 26 times from day 3 to day 37, whereafter it by and large was maintained. Glucose replacement rate decreased to 56% of the day 9 value at day 37 and dropped further to only 32% of the day 9 level at day 52 in two seals, while in another 2 seals it increased at this late stage. The average ketone body replacement rate ranged between 8.6 and 13.8 μmol min‐1 kg‐1, but did not change significantly (P > 0.05) during the fasting period. These results suggest a reduced gluconeogenesis from protein and increased production of ketone bodies, which may in part replace glucose as energy source during fasting.