Acclimation of S. aurata to various salinities alters energy metabolism of osmoregulatory and nonosmoregulatory organs

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology Vol. 54; no. 4; pp. R897 - R907
• Main Authors: SANGIAO-ALVARELLOS, Susana, LAIZ-CARRION, Raul, GUZMAN, José M, MARTIN DEL RIO, Maria P, MIGUEZ, Jesus M, MANCERA, Juan M, SOENGAS, José L
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Physiological Society 01.10.2003
• Subjects: Biological and medical sciences; Energy; Fundamental and applied biological sciences. Psychology; Metabolism; Metabolisms and neurohumoral controls; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Water and mineral metabolism. Osmoregulation. Acidobasic balance; Energy metabolism; Gill; Digestive system; Enzyme; Liver; Central nervous system; Gilthead sea bream; Osmoregulation; Glucose; K; Kidney; Encephalon; Lactates; Vertebrata; Na; Urinary system; Sparus aurata; Pisces; Hydrolases; exchanging ATPase; Adaptation
• ISSN: 0363-6119; 1522-1490

The impact of different environmental salinities on the energy metabolism of gills, kidney, liver, and brain was assessed in gilthead sea bream (Sparus aurata) acclimated to brackish water [BW, 12 parts/thousand (ppt)], seawater (SW, 38 ppt) and hyper saline water (HSW, 55 ppt) for 14 days. Plasma osmolality and levels of sodium and chloride presented a clear direct relationship with environmental salinities. A general activation of energy metabolism was observed under different osmotic conditions. In liver, an enhancement of glycogenolytic and glycolytic potential was observed in fish acclimated to BW and HSW compared with those in SW. In plasma, an increased availability of glucose, lactate, and protein was observed in parallel with the increase in salinity. In gills, an increased Na+-K+-ATPase activity, a clear decrease in the capacity for use of exogenous glucose and the pentose phosphate pathway, as well as an increased glycolytic potential were observed in parallel with the increased salinity. In kidney, Na+-K+-ATPase activity and lactate levels increased in HSW, whereas the capacity for the use of exogenous glucose decreased in BW- and HSW- acclimated fish compared with SW-acclimated fish. In brain, fish acclimated to BW or HSW displayed an enhancement in their potential for glycogenolysis, use of exogenous glucose, and glycolysis compared with SW-acclimated fish. Also in brain, lactate and ATP levels decreased in parallel with the increase in salinity. The data are discussed in the context of energy expenditure associated with osmotic acclimation to different environmental salinities in fish euryhaline species.