chondroitin-sulfates and Hyperinsulinism

This study was to investigate the effects of fucosylated chondroitin sulfate (CHS) from sea cucumber on insulin sensitivity in skeletal muscle of type 2 diabetic mice induced by a high-fat high-sucrose diet (HFSD). CHS supplementation for 19 wk significantly improved insulin sensitivity by 20%, and reduced blood glucose and insulin levels. Western blotting assay showed that CHS significantly increased insulin-stimulated glucose transporter 4 (GLUT4) translocation to 1.7-fold, phosphorylation of phosphoinositide 3-kinase (PI3K) at p85 to 5.0-fold, protein kinase B (PKB) at Ser473 to 1.5-fold, and Thr308 to 1.6-fold in skeletal muscle. However, PI3K, PKB, and GLUT4 total proteins expression were unchangeable. In addition, qRT-PCR analysis proved that the insulin signaling was activated by CHS treatment, showing the increased mRNA expressions of glucose uptake-related key genes. It indicated that CHS improved insulin sensitivity by activation of PI3K/PKB signaling in skeletal muscle of type 2 diabetic mice. Identification of potential mechanism by which CHS increased insulin sensitivity might provide a new functional food or pharmaceutical application of sea cucumber.

Topics: Animals; Blood Glucose; Chondroitin Sulfates; Diabetes Mellitus, Experimental; Glucose Transporter Type 4; Hyperinsulinism; Insulin; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Muscle, Skeletal; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Sea Cucumbers; Signal Transduction

Weanling sand rats (Psammomys obesus) develop hyperinsulinemia or diabetes or both, if fed a standard laboratory diet without a supplement of fiber rich salt bush. The annuli fibrosi of hyperinsulinemic or diabetic animals, which are still hyperinsulinemic, show a slight but statistically significant increase in chondroitin sulfate and a lesser, statistically nonsignificant increase in keratan sulfate. Possible causes of these changes are discussed and the likelihood of a role of hyperinsulinism in their production is pointed out.

Topics: Animal Feed; Animals; Arvicolinae; Chondroitin Sulfates; Diabetes Mellitus, Experimental; Diet; Hyperinsulinism; Intervertebral Disc; Keratan Sulfate; Plants, Edible; Proteoglycans; Spectrophotometry; Weaning