Regulations on glucose metabolism affected by dietary carbohydrate in different strains of juvenile gibel carp (Carassius gibelio)

Abstract

This experiment was conducted to study the effects of dietary carbohydrate on glucose metabolism in gibel carp (Carassius gibelio) as well to investigate if different clones had different responses to carbohydrate intake. Unselected Dongting strain (DT strain), selected gibel carp “CAS III” (A strain) and gibel carp “CAS V” (F strain) were fed with no corn starch diet (0C), 30% corn starch diet (30C) and 45% corn starch diet (45C) for 8 weeks. The results showed that selected F strain showed higher growth performance. F strain and A strain showed better control on postprandial glucose regulation by increasing plasma triglyceride, plasma cholesterol, liver and muscle glycogen contents and also enhancing glycolysis and restraining gluconeogenesis. DT strain had higher body lipid and lipid utilization. In conclusion, gibel carp could tolerate 45% dietary carbohydrate and F strain showed better growth by increasing glycolysis while decreasing glycogenesis.

Genetically Based Physiological Responses to Overwinter Starvation in Gibel Carp (Carassius gibelio)

“…However, strain F starved for 38 and 77 days exhibited lower expression levels. Previous results showed that strain A had higher gene expression levels of pk than strain F when the fish were fed diets containing different levels of carbohydrate or lipid (25,26). In the present study, strain A still presented higher pk mRNA levels than strain F under starvation during winter.…”

“…Strain A had lower plasma glucose levels but higher liver glycogen contents and higher mRNA levels of fbpase and pepck than strain F. The previous results showed that these two strains had no significant differences in mRNA of fbpase or pepck when fed different diets (25,26). Therefore, we suggested that strain A and strain F might have different responses in glucose metabolism to starvation and low temperature.…”

“…Therefore, we suggested that strain A and strain F might have different responses in glucose metabolism to starvation and low temperature. As gluconeogenesis can be induced by starvation (8,30), this indicated that strain A would have a stronger response in gluconeogenesis than strain F. These two strains have been reported to have no significant differences in mRNA levels of acc, fas, or cpt1a when fed diets containing different lipid or glucose levels, but there were differences when the fish were fed different protein sources (25,26,49). Moreover, our data showed that strain A exhibited higher mRNA levels of acc, fas, and cpt1a than strain F. Fasting would induce fatty acid oxidation but decrease lipogenesis in fish (4,8), suggesting that strain A exhibited higher levels of lipid metabolism to cope with the overwintering starvation compared to strain F.…”

“…Two strains of gibel carp reproduced by unisexual gynogenesis, strain A (CAS III) and strain F (CAS V), showed differences in lipid metabolism and glucose metabolism in previous studies. The strain F exhibited better growth performance, lipid utilization, and glucose homeostasis ability than the strain A (25,26). As a warm water fish, gibel carp stop moving and dramatically decrease feed intake or even stop feeding during winter.…”

Carbohydrate molecule size affects the metabolic and digestive dynamics of jundiá (Rhamdia quelen)

“…However, even in species with similar nutritional requirements, there are morphological and physiological differences that change digestive and absorption speed (Kamalam et al, ) and affect animal performance. Therefore, monomeric composition and degree of carbohydrate polymerization must also be considered for diet composition, since metabolic utilization and net energy value of simple sugars and complex polysaccharides appear to be dependent on fish species (Song et al, ). In general, apparent digestibility and intestinal uptake decrease with increased complexity (glucose > dextrin > starch).…”