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

• Published in: Frontiers in Physiology
• Main Authors: Tharmini Kalananthan, Koji Murashita, Ivar Rønnestad, Mitsumasa Ishigaki, Kota Takahashi, Marta S. Silva, Yuki Wakabayashi, Floriana Lai, Munetaka Shimizu, Tom O. Nilsen, Enrique Pino Martinez, Ana S. Gomes
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media S.A. 2020
• Subjects: Atlantic salmon; hypothalamus; agrp; pomc; fullness; fasting; Physiology; QP1-981; Salmo salar
• Online Access: https://doi.org/10.3389/fphys.2020.00061; https://doaj.org/article/9935098eb6924f02b37046544994231a

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 (Salmo salar) post smolts were subjected to (1) fasting for 3 days (fast) and (2) normal feeding (fed), resulting in a significant (p < 0.05) upregulation of hypothalamic agrp1 transcripts levels in the fast group. Moreover, the mRNA abundance of agrp1 was significantly (p < 0.05) correlated with the stomach dry weight content. Corresponding inverse patterns were observed for pomca2, albeit not statistically significant. No significant differences were found for the other paralogues, agrp2 and pomca1 and b, between fed and fast groups. The significant correlation between stomach fullness and agrp1 mRNA expression suggests a possible link between the stomach filling/distension and satiety signals. Our study indicates that hypothalamic agrp1 acts as an orexigenic signal in Atlantic salmon.