Glucose-induced insulin release depends on functional cooperation between islet cells.
Similar to other endocrine glands, the endocrine pancreas displays a characteristic topography of its constituent cells. The functional significance of this structural organization was examined by measuring the secretory activity of the B cell in rat islet cell preparations of different composition. Glucose released 30-fold more insulin from B cells lodged within intact islets as from purified single B cells; structurally coupled B cells and single B cells isolated with A cells or incubated with glucagon responded 4- and 2-fold, respectively, more effectively to glucose than single B cells alone. Glucose homeostasis is thus dependent not only on the number and integrity of the insulin-containing B cells but also on their interactions with neighboring B and non-B cells. This study provides direct support for the concept that the microanatomy of the islet creates the anatomical basis for functional cooperation between islet cells and hence for an appropriate glucose-induced insulin release.
D000818:Animals; D002450:Cell Communication; D002478:Cells, Cultured; D005934:Glucagon / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000502:physiology*; D008297:Male; D051381:Rats; D012636:Secretory Rate / Q000187:drug effects
D007328:Insulin; D005934:Glucagon; D005947:Glucose