title: Dietary virgin olive oil enhances secretagogue-evoked calcium signaling in rat pancreatic acinar cells.
abstract: OBJECTIVE
  We evaluated the long-term effects of a fat-enriched diet (virgin olive oil) on calcium mobilization and amylase secretion induced by cholecystokinin-octapeptide (CCK-8) in rat pancreatic acinar cells. Olive oil is a major component of the Mediterranean diet, and its role in human health is actively being debated.
  
  
  METHODS
  Weaning male Wistar rats (21 d old) were assigned to one of two experimental groups and fed for 8 wk with a commercial chow (control group) or an experimental diet (olive group) containing 100 g/kg of virgin olive oil as dietary fat. Intracellular free calcium [Ca(2+)](i) levels were determined by loading the pancreatic cells with the fluorescent ratio-metric calcium indicator Fura-2 on an inverted fluorescent microscope. For measurement of amylase secretion, cells were incubated with the appropriate secretagogue for 30 min, and amylase activities in the supernatant were determined by the Phadebas blue starch method. Analysis of variance was used to test differences between groups.
  
  
  RESULTS
  Compared with the control group, the CCK-8-induced increase in [Ca(2+)](i) occurred in cells from rats in the olive group (P < 0.05). This stimulatory effect of dietary virgin olive oil was observed in calcium oscillations and large [Ca(2+)](i) transients induced by low (20 pM/L) and high (10 nM/L) concentrations of CCK-8, respectively. In addition to the effects of dietary virgin olive oil on calcium mobilization, it increased (P < 0.05) amylase secretion in response to CCK-8. Olive oil treatment did not significantly alter resting [Ca(2+)](i) or amylase release values compared with the control group. Similar results were obtained when pancreatic acinar cells were stimulated with a high concentration of acetylcholine (10 microM/L).
  
  
  CONCLUSIONS
  The present results demonstrate that a diet supplemented with virgin olive oil can modify pancreatic cell function as assessed by [Ca(2+)](i) mobilization and amylase release evoked by secretagogues in rat pancreatic acinar cells. A role for fatty acids in calcium signaling is suggested.
authors.affiliation: Institute of Nutrition and Food Technology, Department of Physiology, University of Granada, Granada, Spain.
authors.forename: María A
authors.initials: MA
authors.lastname: Martínez
authors.forename: Ana I
authors.initials: AI
authors.lastname: Lajas
authors.forename: María D
authors.initials: MD
authors.lastname: Yago
authors.forename: Pedro C
authors.initials: PC
authors.lastname: Redondo
authors.forename: María P
authors.initials: MP
authors.lastname: Granados
authors.forename: Antonio
authors.initials: A
authors.lastname: González
authors.forename: Juan A
authors.initials: JA
authors.lastname: Rosado
authors.forename: Emilio
authors.initials: E
authors.lastname: Martínez-Victoria
authors.forename: Mariano
authors.initials: M
authors.lastname: Mañas
authors.forename: José A
authors.initials: JA
authors.lastname: Pariente
mesh_terms: D000681:Amylases / Q000187:drug effects / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects* / Q000502:physiology; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D019587:Dietary Supplements; D005453:Fluorescence; D005526:Food, Formulated; D008297:Male; D000069463:Olive Oil; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D010938:Plant Oils / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012844:Sincalide / Q000187:drug effects / Q000494:pharmacology*
chemical_list: D004042:Dietary Fats, Unsaturated; D000069463:Olive Oil; D010938:Plant Oils; D000681:Amylases; D012844:Sincalide; D002118:Calcium