Acrp30 (adipocyte complement-related protein of 30kD), also known as AdipoQ, APM1, Adiponectin, Gelatin binding protein 28kD/GBP28 or adipocyte most abundant gene transcript) was identified as a novel adipocyte-specific synthesized and secreted protein with structural resemblance to complement factor C1q. Like adipsin, Acrp30 secretion is induced ~10-fold during adipocyte differentiation. Plasma levels are reduced in obese humans, and low levels are associated with insulin-resistance. Treatment of db/db mice with TZD increased Acrp30 levels. Acrp30 is proteolytically cleaved at 104 aa to generate the globular Acrp30 (gAcrp30). Administration of gAcrp30 into mice fed a diet high in fat and sugar caused substantial weight loss. A marked reduction in plasma triglycerides, glucose, and free fatty acids was attributed due in part to increased fatty acid oxidation by muscle. Full length Acrp30 was less potent than gAcrp30. Adiponectin receptor 2/ADIPOR2, a 311-aa protein (mouse) with a Mol.wt of 35.4kD and human ADIPOR2 has 299aa which shares 95.2% homology with that of mouse. The ADIPOR2 serves as receptor for globular and full-length adiponectin and mediate increased AMPK and PPAR-alpha ligand activities, as well as fatty acid oxidation and glucose uptake by adiponectin. ADIPOR2 is most abundantly expressed in Liver.