Fatty acid-sensing mechanisms in the hypothalamus of European sea bass (Dicentrarchus labrax): The potential role of monounsaturated and polyunsaturated fatty acids

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Martins, N (Author) Other; Magalhaes, R (Author) Other; Castro, C (Author) Other; Oliva Teles, A (Author) FCUP; Peres, H (Author) FCUP

Journal

Title: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology

Vol. 280

ISSN: 1095-6433

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus

Other information

Authenticus ID: P-00X-ZFM

DOI: 10.1016/j.cbpa.2023.111397

Abstract (EN): This study aimed to evaluate the hypothalamus fatty acid (FA)-sensing mechanisms response to different FA in European sea bass. For that purpose, fish (body weight of 90 g) were intraperitoneally (IP) injected (time 0 h) with five long-chain unsaturated fatty acids, namely, docosahexaenoic acid (DHA; C22:5n3); eicosapentaenoic acid (EPA; C20:4n3); alpha-linolenic (ALA; C18:3n3); linoleic acid (LA; C18:2n6) and oleic acid (OA; C18:1n9) at a dose of 300 mu g kg-1, or with 0.9% saline solution (control). Feed intake (FI) was recorded at 3, 6, and 24 h after the IP injection. One week later, fish were IP injected with the same FA, and the hypothalamus was collected 3 h after the IP injection for measurement of molecules related to FI regulation and FA-sensing mechanisms. Cu-mulative FI (g/kg/day) was not affected by treatments. However, compared to the control, FI increased with the OA treatment at 6 h after the IP injection. FI decreased with mealtime in the DHA and LA groups. Gene expression of orexigenic (npy/agrp) and anorexigenic (cart2/pomc1) neurons was not affected by the FA treat-ments. Attending the enzymes involved in the FA-sensing mechanisms activation, compared to the control carnitine palmitoyltransferase I (CPT1) and ATP citrate lyase (ACLY) activity were not affected by FA treatments. Contrarily the key enzymes of lipid metabolisms, malic enzyme and hydroxyacylCoA dehydrogenase was higher in fish that received the EPA and OA treatment, than fish treated to the control. Overall, the results of the present study indicate that gene expression of orexigenic and anorexigenic neurons was not affected at 3 h after IP in-jection with different FA. However, the activity of key enzymes of lipid metabolism was differently affected by circulating FA, indicating that FA-sensing mechanisms respond to different FA. Further studies are required involving different sampling times to further characterize the response of FA-sensing mechanisms to FA. These findings may be of relevance to the aquaculture industry in an era where alternative lipid sources are being increasingly used.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8