Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Researchers discover a way to improve glucose regulation in fish

Photo of a largemouth bass by Jonathunder via Wikimedia Commons

Many species of carnivorous fish have a difficult time metabolizing carbohydrates, resulting in hyperglycemia. In these affected species, lipids and glycogen (the storage form of glucose) build up in tissues and their growth is slowed when they are fed carbohydrate-rich diets. In addition, these fish continue to produce glucose (through gluconeogenesis) even if they consume it in their diets, which worsens their hyperglycemia. This is a major concern in the aquaculture industry as carbohydrate-rich diets are less expensive.

In a recent study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, researchers tested dietary approaches to improve glucose metabolism in a species of carnivorous freshwater fish, largemouth bass (Micropterus salmoides). Fish were fed a diet high in carbohydrates with or without sodium oxamate supplementation. Sodium oxamate inhibits the production of lactate, which prevents it from being converted to glucose through gluconeogenesis.

The researchers found that fish fed the high carbohydrate diet gained less weight and had elevated blood glucose, insulin, triglycerides, and lactate concentrations compared to fish fed a standard amount of carbohydrates. In addition, the animals fed the high carbohydrate diet accumulated glycogen and lipids in their tissues. In contrast, fish fed the high carbohydrate diet gained more weight and had improved glucose tolerance and lower lactate concentrations if they were supplemented with sodium oxamate. These findings indicate that sodium oxamate can improve glucose homeostasis and growth of carnivorous fish fed a high carbohydrate diet.


H-C Shen, Z-Q Chen, X-C Liu, J-F Guan, D-Z Xie, Y-Y Li, C Xu. Sodium oxamate reduces lactate production to improve the glucose homeostasis of Micropterus salmoides fed high-carbohydrate diets. American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. 324(2): R227-R241, 2023.

Categories: Agriculture, Aquaculture, and Livestock, Diet and Exercise

Tags: , , , , , , ,

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s