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This Article Full Text Full Text (PDF) All Versions of this Article: 289/1/R259    most recent 00574.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Albalat, A. Articles by Navarro, I. Search for Related Content PubMed PubMed Citation Articles by Albalat, A. Articles by Navarro, I.

COMPARATIVE AND EVOLUTIONARY PHYSIOLOGY

Nutritional and hormonal control of lipolysis in isolated gilthead seabream (Sparus aurata) adipocytes

¹Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; ²Instituto Acuicultura Torre de la Sal, Castellón, Spain; ³Laboratoire de Nutrition des Poissons, Unitée Mixte INRA-IFREMER, Saint-Pée-sur-Nivelle, France; ⁴Department of Integrative Zoology, Institute Biology, Leiden University, Leiden, The Netherlands

Submitted 23 August 2004 ; accepted in final form 26 February 2005

We examined the effects of diet composition and fasting on lipolysis of freshly isolated adipocytes from gilthead seabream (Sparus aurata). We also analyzed the effects of insulin, glucagon, and growth hormone (GH) in adipocytes isolated from fish fed with different diets. Basal lipolysis, measured as glycerol release, increased proportionally with cell concentration and time of incubation, which validates the suitability of these cell preparations for the study of hormonal regulation of this metabolic process. Gilthead seabream were fed two different diets, FM (100% of fish meal) and PP (100% of plant protein supplied by plant sources) for 6 wk. After this period, each diet group was divided into two groups: fed and fasted (for 11 days). Lipolysis was significantly higher in adipocytes from PP-fed fish than in adipocytes from FM-fed fish. Fasting provoked a significant increase in the lipolytic rate, about threefold in isolated adipocytes regardless of nutritional history. Hormone effects were similar in the different groups: glucagon increased the lipolytic rate, whereas insulin had almost no effect. GH was clearly lipolytic, although the relative increase in glycerol over control was lower in isolated adipocytes from fasted fish compared with fed fish. Together, we demonstrate for the first time that lipolysis, measured in isolated seabream adipocytes, is affected by the nutritional state of the fish. Furthermore, our data suggest that glucagon and especially GH play a major role in the control of adipocyte lipolysis.

fish; nutritional and hormonal regulation; insulin; glucagon; growth hormone; fasting