AUTHOR=Kalananthan Tharmini , Murashita Koji , Rønnestad Ivar , Ishigaki Mitsumasa , Takahashi Kota , Silva Marta S. , Wakabayashi Yuki , Lai Floriana , Shimizu Munetaka , Nilsen Tom O. , Pino Martinez Enrique , Gomes Ana S. 

TITLE=Hypothalamic agrp and pomc mRNA Responses to Gastrointestinal Fullness and Fasting in Atlantic Salmon (Salmo salar, L.)

JOURNAL=Frontiers in Physiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2020.00061

DOI=10.3389/fphys.2020.00061

ISSN=1664-042X

ABSTRACT=<p>The orexigenic agouti-related protein (AgRP) and the anorexigenic pro-opiomelanocortin (POMC) are crucial players in the control of feed intake in vertebrates, yet their role in teleosts has not been fully established. Triplicate groups of Atlantic salmon (<italic>Salmo salar</italic>) post smolts were subjected to (1) fasting for 3 days (fast) and (2) normal feeding (fed), resulting in a significant (<italic>p</italic> &lt; 0.05) upregulation of hypothalamic <italic>agrp1</italic> transcripts levels in the fast group. Moreover, the mRNA abundance of <italic>agrp1</italic> was significantly (<italic>p</italic> &lt; 0.05) correlated with the stomach dry weight content. Corresponding inverse patterns were observed for <italic>pomca2</italic>, albeit not statistically significant. No significant differences were found for the other paralogues, <italic>agrp2</italic> and <italic>pomca1</italic> and <italic>b,</italic> between fed and fast groups. The significant correlation between stomach fullness and <italic>agrp1</italic> mRNA expression suggests a possible link between the stomach filling/distension and satiety signals. Our study indicates that hypothalamic <italic>agrp1</italic> acts as an orexigenic signal in Atlantic salmon.</p>