Insulin secretion and DNA synthesis of cultured islets of Langerhans are influenced by the matrix.
To compare the effect of matrix on glucose-stimulated insulin release, we cultured neonatal (3- to 5-day-old) rat islets of Langerhans, devoid of mesenchymal cell, on fibronectin, Cell-Tak, or endothelial basement membranes, free-floating, or dispersed into single cells. We also examined the rate of DNA synthesis during the culture period. Compared to free-floating islets [0.386 +/- 0.03 (SEM) ng per 24 h/ng total], single-cell cultures had the lowest basal insulin release (0.159 +/- 0.03 ng per 24 h/ng total; p < 0.0001), which was also low in islets attached to endothelial basement membrane (0.294 +/- 0.02 ng per 24 h/ng total; p = 0.01). The spontaneous insulin release (1 h in medium with 2.7 mM glucose) was lowest in islets attached to endothelial basement membrane (0.003 +/- 0.00023 ng per h/ng total; p < 0.0001 vs. free-floating) and highest in single-cell cultures (0.01153 +/- 0.00259 ng per h/ng total; p = 0.039 vs. free-floating). The ability to increase insulin release following a glucose challenge (16.1 mM for 1 h) was highest in islets grown on endothelial basement membranes (16.4-fold) and fibronectin (12.6-fold) compared to free-floating islets (8.7-fold), Cell-Tak (7.9-fold), and single-cell cultures (5.4-fold).(ABSTRACT TRUNCATED AT 250 WORDS)
Hulinsky
I
I
Ray Williams Institute of Paediatric Endocrinology, Diabetes and Metabolism, Royal Alexandra Hospital for Children, Sydney, Australia.
Harrington
J
J
Cooney
S
S
Silink
M
M
D000818:Animals; D000831:Animals, Newborn; D001485:Basement Membrane / Q000378:metabolism; D002448:Cell Adhesion; D002455:Cell Division; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration / Q000502:physiology*
D007328:Insulin; D004247:DNA