Amylin Inhibits the Feeding of the Siberian Sturgeon

Abstract

Amylin is a 37-amino acid polypeptide that has been shown to be involved in feeding regulation in a few mammals, birds and goldfish. To study whether amylin regulates the feeding of Siberian sturgeon, this study cloned amylin of Siberian sturgeon and detected the distribution pattern of amylin in 15 tissues, the expression level in periprandial (pre- and post-feeding), and the changes of food intake and related appetite factors after intraperitonal injection experiment. The results showed that the expression of amylin was highest in hypothalamus, followed by duodenum, telencephalon, forebrain, midbrain, heart and liver, and low in cerebellum, pancreas, valvular intestine and other detection tissues. Compared with 1h pre-feeding, the expression level of amylin in hypothalamus was significantly increased at 1h post-feeding (P < 0.05), and the expression level of amylin in duodenum was extremely significantly increased at 1h post-feeding (P < 0.01). Compared with the control group (normal saline), the food intake at 0-1h and 1-3h after intraperitoneal injection of 100 ng/g BW and 200 ng/g BW was significantly decreased (P < 0.05), and the food intake at 3-6h in 100 ng/g BW group was extremely significantly decreased (P < 0.01), and the food intake at 3-6h in 200 ng/g BW group was significantly decreased (P < 0.05). After 1h of injection of 100 ng/g amylin, MC4R in hypothalamus was significantly increased (P < 0.05) and somatostatin was extremely significantly increased (P < 0.01), while amylin and NPY were significantly decreased (P < 0.05). CCK in valvular intestine was extremely significantly increased (P < 0.01), insulin in duodenum was significantly increased (P < 0.05), but ghrelin in duodenum had no significant change (P > 0.05). These results showed that Amylin inhibited feeding in Siberian sturgeon by down-regulating appetite stimulating factor NPY and up-regulating appetite suppressing factors somatostatin , MC4R , CCK and insulin .