No abstract

Glucosamine has been widely used to treat osteoporosis in clinic and it shows an effect on hexosamine biosynthetic pathway in glucose-induced insulin resistance. However, glucosamine and chronic hyperglycemia is not correlative. Thus, we used C (2)C (12) cell line to carry out the uptake assay of 2-[14C]-deoxy-d-glucose and [3H]-glucosamine. Glucosamine inhibited the in vitro glucose uptake in a concentration-dependent manner. The glucose transporter GLUT4 prepared for [3H]-glucosamine uptake showed a concentration-dependent competition between glucose and glucosamine uptake. The effects of glucosamine on glucose tolerance and homeostasis model assessment (HOMA) were also determined in normal Wistar and fructose-fed rats. Both plasma glucose levels and/or HOMA index were not changed in normal rats treated with glucosamine as compared with the saline-treated control. However, we found that glucosamine exhibited an effect on the expression of farnesoid X receptor in liver to exacerbate the values of HOMA and accelerate the development of insulin resistance in fructose-fed rats. Thus, glucosamine should be applied with caution in type-2 diabetic patients.

To compare the pork quality, eight three-way crossbreeds were selected. The pigs with an initial weight of 25 kg were selected and raised to 115 kg under similar nutritional levels. The meat quality, fatty acid composition, and free amino acid contents of loins (longissimus dorsi) and butts (supraspinatus) were compared after the trial. The results showed that the Canadian Duroc × France Landrace × France Yorkshire (GC) pig loins had the highest pH 24h value (P<0.05). The PIC399 × France Landrace × France Yorkshire (GP) pig loins had the highest inosine monophosphate content (P<0.05), whereas the old American-line Duroc (imported before 2013) × new American-line Landrace × new American-line Yorkshire (XO) pig loins had the highest total, essential, and delicious amino acid contents (P<0.05). The chemical composition, sensory evaluation, and fatty acid composition of all pork were similar (P>0.05). These results suggest that the GC pig loins had a long shelf life, the GP pig loins were appealing, and the XO pig loins were delicious and nutritious. Thus, while choosing crossbreeds, it is important to recognize that the meat quality relies on the hybridization.