Hepatopancreas gluconeogenesis and glycogen content during fasting in crabs previously maintained on a high-protein or carbohydrate-rich diet.
The present study assessed the effect of different fasting times on the in vitro gluconeogenic capacity of Chasmagnathus granulata crabs previously adapted to a high-protein (HP) or carbohydrate-rich (HC) diet using the incorporation of [U-(14)C]l-lactate or [U-(14)C]l-alanine into glucose. We also recorded haemolymphatic glucose and hepatopancreatic glycogen levels. In the HP group, on the third day of fasting there were decreases in the synthesis of glucose from (14)C-alanine and in haemolymph glucose. After 15 days of fasting, haemolymph glucose and hepatopancreatic glycogen levels were maintained by an increase in the conversion of (14)C-alanine into glucose. However, after 21 days of fasting the gluconeogenic capacity was decreased and hepatopancreas glycogen concentration was reduced. In the HC group, hepatopancreatic glycogen was the energy source during the first 6 days of fasting. Gluconeogenesis from (14)C-lactate decreased after 6 days of fasting, remaining low until 21 days of fasting. The conversion of (14)C-alanine into glucose was increased after 15 days fasting and hepatopancreatic glycogen was raised in relation to that present after a 6-day fasting. In both dietary groups the stabilization in the levels of haemolymph glucose after 21 days fasting may result from a reduction in metabolic rate during restricted feeding.
Oliveira
Guendalina T
GT
Departamento de Ciências Fisiológicas, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, Av. Ipiranga, 6681 pd.12, 90619-900 Porto Alegre, RS, Brazil.
Rossi
Isabel Cristina
IC
Kucharski
Luiz C
LC
Da Silva
Roselis S M
RS
D000409:Alanine / Q000378:metabolism; D000818:Animals; D003386:Brachyura / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D005215:Fasting / Q000502:physiology; D005943:Gluconeogenesis / Q000502:physiology; D005947:Glucose / Q000032:analysis; D006003:Glycogen / Q000378:metabolism*; D006458:Hemolymph / Q000737:chemistry; D043143:Hepatopancreas / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D011506:Proteins / Q000378:metabolism
D011506:Proteins; D019344:Lactic Acid; D006003:Glycogen; D005947:Glucose; D000409:Alanine