Osteocalcin as a hormone regulating glucose metabolism

Figure 3 Schematic representation of the regulation of insulin secretion by leptin. Leptin directly inhibits insulin expression in pancreas. Leptin activates SNS by decreasing serotonin and cAMP response element binding protein in hypothalamus, and then enhanced SNS suppresses osteoblast differentiation and osteocalcin expression through the Adrβ2 in osteoblasts. Thus, leptin indirectly inhibits insulin expression via central nervous system and bone. SNS: Sympathetic nervous system.