Cortisol emphasizes the metabolic strategies employed by common carp, Cyprinus carpio at different feeding and swimming regimes.
The objective of this study was to investigate the interaction between feeding, exercise and cortisol on metabolic strategies of common carp over a 168h post-implant period. Feeding provided readily available energy and clearly increased muscle and liver protein and glycogen stores. Swimming, feeding and cortisol all induced aerobic metabolism by increasing oxygen consumption, and stimulated protein metabolism as demonstrated by the increased ammonia and urea excretion and ammonia quotient. Hypercortisol stimulated ammonia self-detoxifying mechanisms by enhancing ammonia and urea excretion, especially during severe exercise. At high swimming level, higher branchial clearance rates in cortisol treated fish succeeded in eliminating the elevation of endogenous ammonia, resulting in reduced plasma Tamm levels compared to control and sham implanted fish. Carp easily induced anaerobic metabolism, both during routine and active swimming, with elevated lactate levels as a consequence. Both feeding and cortisol treatment increased this dependence on anaerobic metabolism. Hypercortisol induced both glycogenesis and gluconeogenesis resulting in hyperglycemia and muscle and liver glycogen deposition, most likely as a protective mechanism for prolonged stress situations and primarily fuelled by protein mobilization.
Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Groenenborgerlaan 171, BE-2020 Antwerp, Belgium; Institute of Tropical Aquaculture, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia. Electronic address: honjung@umt.edu.my.
Hon Jung
HJ
Liew
Daniela
D
Chiarella
Antonella
A
Pelle
Caterina
C
Faggio
Ronny
R
Blust
Gudrun
G
De Boeck
D000641:Ammonia / Q000097:blood / Q000652:urine; D000818:Animals; D001786:Blood Glucose; D002347:Carps / Q000378:metabolism*; D004734:Energy Metabolism; D005247:Feeding Behavior; D029941:Fish Proteins / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood* / Q000502:physiology; D019344:Lactic Acid / Q000097:blood; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D010101:Oxygen Consumption; D013312:Stress, Physiological; D013550:Swimming; D014508:Urea / Q000097:blood / Q000652:urine
D001786:Blood Glucose; D029941:Fish Proteins; D019344:Lactic Acid; D000641:Ammonia; D014508:Urea; D006003:Glycogen; D006854:Hydrocortisone
Aerobic metabolism; Ammonia excretion; Anaerobic metabolism; Critical swimming speed; Energy budget; Respirometry; Stress; Urea