Table 1.

Different cell types in the adult human endocrine pancreatic islet and their characteristics

	Cell types
	α-cells	β-cells	δ-cells	γ-cells	ε cells
Hormone secreted	Glucagon	Insulin	Somatostatin	Pancreatic polypeptide	Ghrelin
Molecular weight (kDa)	3.5	5.8	1.5	4.2	3.4
Amino acids	29	51	14	36	28
Half-life (min)	8–18	15	1–3	6–7	27–31
Volume % (adult)	30–45	55–75	< 10	< 10	< 1
Specific transcription factors	Nkx2.2, Arx, MafB,	Pdx1, Nkx6.1, MafA, MafB	Pax4, Pdx1,	Nkx2.2, Arx,	?

Pdx1 pancreatic duodenal homeobox gene 1, Nkx2.2 NK class of homeodomain-encoding genes 2.2, Nkx6.1 NK class of homeodomain-encoding genes 6.1, MafA V-maf musculoaponeurotic fibrosarcoma oncogene family protein A, MafB V-maf musculoaponeurotic fibrosarcoma oncogene family protein B, Arx aristaless paired-class homeobox gene, Pax4 paired homeodomain factor 4, ?: not determined yet