title: Glucose generates coincident insulin and somatostatin pulses and antisynchronous glucagon pulses from human pancreatic islets.
abstract: The kinetics of insulin, glucagon and somatostatin release was studied in human pancreatic islets. Batches of 10-15 islets were perifused and the hormones measured with RIA in 30-sec fractions. Increase of glucose from 3 to 20 mm resulted in a brief pulse of glucagon coinciding with suppression of basal insulin and somatostatin release. There was a subsequent drop of glucagon release concomitant with the appearance of a pronounced pulse of insulin and a slightly delayed pulse of somatostatin. Continued exposure to 20 mm glucose generated pulsatile release of the three hormones with 7- to 8-min periods accounting for 60-70% of the secreted amounts. Glucose caused pronounced stimulation of average insulin and somatostatin release. However, the nadirs between the glucagon pulses were lower than the secretion at 3 mm glucose, resulting in 18% suppression of average release. The repetitive glucagon pulses were antisynchronous to coincident pulses of insulin and somatostatin. The resulting greater than 20-fold variations of the insulin to glucagon ratio might be essential for minute-to-minute regulation of the hepatic glucose production.
authors.affiliation: Department of Medical Cell Biology, University of Uppsala, Uppsala, Sweden. bo.hellman@mcb.uu.se
authors.forename: Bo
authors.initials: B
authors.lastname: Hellman
authors.forename: Albert
authors.initials: A
authors.lastname: Salehi
authors.forename: Erik
authors.initials: E
authors.lastname: Gylfe
authors.forename: Heléne
authors.initials: H
authors.lastname: Dansk
authors.forename: Eva
authors.initials: E
authors.lastname: Grapengiesser
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D002102:Cadaver; D004305:Dose-Response Relationship, Drug; D005260:Female; D005934:Glucagon / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D013004:Somatostatin / Q000378:metabolism*; D013997:Time Factors
chemical_list: D007328:Insulin; D013004:Somatostatin; D005934:Glucagon; D005947:Glucose