title: Small human islets comprised of more β-cells with higher insulin content than large islets.
abstract: For the past 30 years, data have suggested that unique islet populations exist, based on morphology and glucose sensitivity. Yet little has been done to determine the mechanism of these functional differences. The purpose of this study was to determine whether human islets were comprised functionally unique populations, and to elucidate a possible mechanism. Islets or pancreatic sections from 29 human donors were analyzed. Islets were isolated and measured for insulin secretion, cell composition and organization, insulin and glucagon granule density and insulin content. Insulin secretion was significantly greater in small compared with large islets. In sectioned human pancreata, β-cells comprised a higher proportion of the total endocrine cells in small islets (63%) than large islets (39%). A higher percentage of β-cells in small islets contacted blood vessels (44%) compared with large islets (31%). Total insulin content of isolated human islets was significantly greater in the small (1323 ± 512 μIU/IE) compared with large islets (126 ± 48 μIU/IE). There was less immunostaining for insulin in the large islets from human pancreatic sections, especially in the core of the islet, compared with small islets. The results suggest that differences in insulin secretion between large and small islets may be due to a higher percentage of β-cells in small islets with more β-cells in contact with blood vessels and a higher concentration of insulin/β-cell in small islets.
authors: School of Medicine, University of Kansas Medicine Center, Kansas City, KS, USA.
authors: Bilal
authors: B
authors: Farhat
authors: Akshay
authors: A
authors: Almelkar
authors: Karthik
authors: K
authors: Ramachandran
authors: S Janette
authors: SJ
authors: Williams
authors: Han-Hung
authors: HH
authors: Huang
authors: David
authors: D
authors: Zamierowksi
authors: Lesya
authors: L
authors: Novikova
authors: Lisa
authors: L
authors: Stehno-Bittel
mesh_terms: D000328:Adult; D002452:Cell Count; D005260:Female; D005934:Glucagon / Q000378:metabolism; D050416:Glucagon-Secreting Cells / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism; D007150:Immunohistochemistry; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism* / Q000648:ultrastructure*; D007515:Islets of Langerhans / Q000098:blood supply / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure*; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D011384:Proinsulin / Q000378:metabolism; D022142:Secretory Vesicles / Q000378:metabolism / Q000648:ultrastructure; D013004:Somatostatin; D019864:Somatostatin-Secreting Cells / Q000378:metabolism / Q000648:ultrastructure; D014015:Tissue Banks; D015854:Up-Regulation
chemical_list: D007328:Insulin; D013004:Somatostatin; D005934:Glucagon; D011384:Proinsulin
keywords: blood vessels; glucagon; human; insulin; islet morphology; islets; lymphatics; α-cell; β-cell
references: Cell Tissue Res. 1980;206(1):157-70
references: 6986987
references: J Anat. 1995 Jun;186 ( Pt 3):629-37
references: 7559135
references: Diabetes. 2007 Mar;56(3):594-603
references: 17327426
references: Tohoku J Exp Med. 1986 May;149(1):1-10
references: 3526638
references: Acta Endocrinol (Copenh). 1984 Mar;105(3):379-84
references: 6199936
references: Life Sci. 2001 Oct 19;69(22):2627-39
references: 11712666
references: AMA Arch Intern Med. 1958 Jun;101(6):1159-71
references: 13532070
references: Am J Physiol. 1948 Jan 1;152(1):36-41
references: 18903424
references: Islets. 2011 Jan-Feb;3(1):6-13
references: 21325888
references: Horm Metab Res. 1999 Sep;31(9):519-24
references: 10569254
references: Islets. 2011 Jan-Feb;3(1):1-5
references: 21266855
references: Tissue Cell. 2012 Oct;44(5):332-41
references: 22717091
references: Proc Natl Acad Sci U S A. 2006 Feb 14;103(7):2334-9
references: 16461897
references: Diabetologia. 2010 May;53(5):937-945
references: 20101386
references: J Clin Invest. 1967 Jun;46(6):903-10
references: 6026096
references: Ann Surg. 1970 Jul;172(1):56-60
references: 4316644
references: Adv Exp Med Biol. 2010;654:21-37
references: 20217492
references: Am J Physiol Endocrinol Metab. 2006 May;290(5):E771-9
references: 16303846
references: Transplantation. 2010 Jan 27;89(2):146-54
references: 20098276
references: Diabetes. 2010 May;59(5):1202-10
references: 20185817
references: Science. 1979 Dec 14;206(4424):1323-5
references: 390711
references: Organogenesis. 2010 Apr-Jun;6(2):115-24
references: 20885858
references: PLoS One. 2013;8(2):e57844
references: 23451276