Table 1: Hormones, growth factors, and other factors regulating beta-cell mass.

Inhibitors Stimulators Metabolites Glucose, FFA Glucose, FFA, amino acids Cytokines IL-1, IFN-g, TNF-a, leptin GH, PRL, PL Growth factor family HGF IGF-I, IGF-II, insulin, TGF-a, betacellulin, HB-EGF, aFGF, VEGF, PDGF, HGF Placental hormones placental lactogen, prolactin Glucagon family GLP-1, GIP, glucagon Somatostatin family Somatostatin CGRP family IAPP/amylin Gastrin family Gastrin, CCK TGF-b family TGF-b, follistatin Activin A Neurotrophins NGF, NT-3 Neurotransmitters (Nor)epinephrine Acetylcholine Lectins Reg/INGAP/PSP/PTP Adhesion molecules Integrin a6b1, Cx43, Cx36 Drugs Diazoxide Nicotinamide, SU Toxins Streptozotocin, alloxan

Modified from Nielsen et al. [29]. aFGF, acidic fibroblast growth factor; CCK, cholecystokinin; Cx. Connexin; HB-EGF, heparin-binding EGF-like protein; HGF, hepatocyte growth factor/scatter factor; IAPP, islet amyloid polypeptide; IFN, interferon; IL, interleukin; INGAP, islet neogenesis- associated peptide; NGF, nerve growth factor; NT-3, neurotrophin-3; PDGF, platelet-derived growth factor; PSP, pancreatic stone protein; PTP, pancreatic thread protein; SU, sulfonylurea; TGF, transforming growth factor; TNF, tumor necrosis factor; VEGF, vascular endothelial growth factor.