Dietary virgin olive oil enhances secretagogue-evoked calcium signaling in rat pancreatic acinar cells

• Published in: Nutrition (Burbank, Los Angeles County, Calif.) Los Angeles County, Calif.), 2004-06, Vol.20 (6), p.536-541
• Main Authors: Martínez, María A, Lajas, Ana I, Yago, María D, Redondo, Pedro C, Granados, María P, González, Antonio, Rosado, Juan A, Martínez-Victoria, Emilio, Mañas, Mariano, Pariente, José A
• Format: Article
• Language: English
• Subjects: acetylcholine; amylase release; amylases; Amylases - drug effects; Amylases - secretion; Analysis of Variance; Animals; Biological and medical sciences; Calcium; Calcium - metabolism; calcium signaling; Calcium Signaling - drug effects; Calcium Signaling - physiology; cell communication; Cells; cholecystokinin; Diet; dietary fat; Dietary Fats, Unsaturated - pharmacology; Dietary Supplements; Enzymes; Exocrine pancreas; experimental diets; Fatty acids; Feeding. Feeding behavior; Fluorescence; Food, Formulated; Fundamental and applied biological sciences. Psychology; hormone secretion; human nutrition; Kinases; laboratory animals; Male; mineral content; nutrition physiology; Olive Oil; Pancreas; Pancreas - drug effects; Pancreas - enzymology; Pancreas - secretion; pancreatic acinar cell; Plant Oils - pharmacology; Proteins; Rats; Rats, Wistar; Rodents; secretion; Sincalide - drug effects; Sincalide - pharmacology; Variance analysis; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: digestive system; virgin olive oil
• ISSN: 0899-9007; 1873-1244
• DOI: 10.1016/j.nut.2004.03.018

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. 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. 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 μM/L). 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.