Leptin suppresses basal insulin secretion from rat pancreatic islets.
The effects of leptin on insulin secretion from pancreatic islets of Sprague-Dawley rats were examined in vitro. In a basal glucose medium (5.5 mM), insulin secretion from isolated islets was significantly decreased after addition of a recombinant leptin (80 nM) (3.20+/-0.14 nmol/10 islets/h) compared with that before the addition (4.41+/-0.30 nmol/10 islets/h). Although significant leptin suppression of insulin secretion was not observed under a glucose-stimulated (11.1 mM) condition, these results suggest that a negative feedback system may exist between leptin and insulin, which increases the production of leptin from adipose tissues.
Ishida
K
K
Department of Laboratory Medicine, School of Medicine, The University of Tokushima, Japan.
Murakami
T
T
Mizuno
A
A
Iida
M
M
Kuwajima
M
M
Shima
K
K
D000818:Animals; D002469:Cell Separation; D002478:Cells, Cultured; D003470:Culture Media; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D020738:Leptin; D008297:Male; D009765:Obesity / Q000378:metabolism; D011506:Proteins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D003470:Culture Media; D007328:Insulin; D020738:Leptin; D011506:Proteins; D005947:Glucose