Adiponectin and adiponectin receptors in common carp (Cyprinus carpio): Tissue distribution and their expressions in response to high-carbohydrate and high-lipid diets

Abstract

In order to investigate the roles of adiponectin in glucose and lipid metabolism in common carp, the tissue distribution of adiponectin and its receptor genes in common carp were firstly detected in this study, and then the effects of high-carbohydrate (45%) and high-lipid (11%) diets on their expressions were studied in the feeding trial. The results showed that adipoqa and adipoqb mRNA levels were highest in the red muscle, followed by the heart and white muscle. Adiponectin receptor genes were widely expressed in all tested tissues. Two subtypes of adiponectin receptor 1 genes (adipor1a and adipor1b) were expressed at the highest level in the brain, while adipor2 mRNA was highly expressed in the heart and red muscle. The high-carbohydrate diet significantly up-regulated adipoqa and adipoqb mRNA level in the heart of common carp, while the high-lipid diet significantly promoted adipoqa mRNA expression in the red muscle and heart, compared to the control diet. For adiponectin receptor gene expression, a high-carbohydrate diet up-regulated adipor2 mRNA level in the hepatopancreas, while a high-lipid diet significantly promoted adipor1a, adipor1b and adipor2 mRNA expression in the red muscle and hepatopancreas. The results showed that both high-carbohydrate and high-lipid diets could induce adiponectin genes expression in common carp, and AdipoRs expression was more likely to be increased by the high-lipid diet than the high-carbohydrate diet. This study suggested that adiponectin and its receptors were involved in the metabolic regulation of fish under high dietary carbohydrate and lipid levels.

Keywords

• Common carp
• Adiponectin
• Adiponectin receptor
• Tissue distribution
• High-carbohydrate diet
• High-lipid diet