title: Propionate inhibits glucose-induced insulin secretion in isolated rat pancreatic islets.
abstract: Dietary fibers, probably by generating short chain fatty acids (SCFA) through enterobacterial fermentation, have a beneficial effect on the control of glycemia in patients with peripheral insulin resistance. We studied the effect of propionate on glucose-induced insulin secretion in isolated rat pancreatic islets. Evidence is presented that propionate, one of the major SCFA produced in the gut, inhibits insulin secretion induced by high glucose concentrations (11.1 and 16.7 mM) in incubated and perfused pancreatic islets. This short chain fatty acid reduces [U-(14)C]-glucose decarboxylation and raises the conversion of glucose to lactate. Propionate causes a significant decrease of both [1-(14)C]- (84%) and [2-(14)C]-pyruvate (49%) decarboxylation. These findings indicate pyruvate dehydrogenase as the major site for the propionate effect. These observations led us to postulate that the reduction in glucose oxidation and the consequent decrease in the ATP/ADP ratio may be the major mechanism for the lower insulin secretion to glucose stimulus induced by propionate.
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1524, 05508-900, São Paulo, Brazil.
authors.forename: Helena M A
authors.initials: HM
authors.lastname: Ximenes
authors.forename: Aparecida E
authors.initials: AE
authors.lastname: Hirata
authors.forename: Marlene S
authors.initials: MS
authors.lastname: Rocha
authors.forename: Rui
authors.initials: R
authors.lastname: Curi
authors.forename: Angelo R
authors.initials: AR
authors.lastname: Carpinelli
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000096:biosynthesis* / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D011422:Propionates / Q000494:pharmacology*; D011773:Pyruvates / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012636:Secretory Rate / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D007328:Insulin; D011422:Propionates; D011773:Pyruvates; D019344:Lactic Acid; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate