Multiple potential signalling pathways for adiponectin. Abbreviations: R1 and R2, adiponectin receptor type 1 and 2; AMP kinase, adenosine 5′-monophosphate (AMP)-activated protein kinase; NADPH, nicotinamide adenine dinucleotide phosphate; oxLDL, oxidized low-density lipoprotein; PI-3K, phosphatidylinositol-3-kinase; Akt, agarose kinase target or protein kinase B; ROS, reactive oxygen species; NO, nitric oxide; eNOS, endothelial NO synthase; MAPK, mitogen-activated-protein-kinase. The solid arrows and dotted lines reflect stimulatory and inhibitory effects, respectively. Modified from Goldstein and Scalia: JCEM, June 2004, 89(6):2565.