Who would have thought that carnivorous fish, like the gilthead sea bream pictured above, and people with diabetes have a lot in common? These fish are glucose intolerant, meaning they are not able to use glucose for energy very well.
When these fish are given carbohydrates, their blood sugar increases as does their ability to produce fats through lipogenesis. The purpose of this increase may be to store the excess sugar that was ingested into fats that can be used at a later time for energy.
A new study published in American Journal of Physiology – Regulatory, Integrative and Comparative Physiology explored the mechanism by which the anti-diabetes drug metformin works in a carnivorous fish, the gildhead sea bream. Similar to people, metformin impacted the production of new glucose in the fish, a process called gluconeogenesis. Carnivorous fish prefer diets high in amino acids as they prefer to not only use amino acids for energy, but to also convert them into glucose.
Rashidpour A, Silva-Marrero JI, Segui L, Baanante IV, Meton I. Metformin counteracts glucose-dependent lipogenesis and impairs transdeamination in the liver of gilthead sea bream (Sparus aurata). American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. 316(3):R265-R273, 2019. doi: 10.1152/ajpregu.00216.2018.