title: Melatonin modulates Ca2+ mobilization and amylase release in response to cholecystokinin octapeptide in mouse pancreatic acinar cells.
abstract: In the present work, we have evaluated the effect of an acute addition of melatonin on cholecystokinin octapeptide (CCK-8)-evoked Ca(2+) signals and amylase secretion in mouse pancreatic acinar cells. For this purpose, freshly isolated mouse pancreatic acinar cells were loaded with fura-2 to study intracellular free Ca(2+) concentration ([Ca(2+)](c)). Amylase release and cell viability were studied employing colorimetric methods. Our results show that CCK-8 evoked a biphasic effect on amylase secretion, finding a maximum at a concentration of 0.1 nM and a reduction of secretion at higher concentrations. Pre-incubation of cells with melatonin (1 μM-1 mM) significantly attenuated enzyme secretion in response to high concentrations of CCK-8. Stimulation of cells with 1 nM CCK-8 led to a transient increase in [Ca(2+)](c), followed by a decrease towards a constant level. In the presence of 1 mM melatonin, stimulation of cells with CCK-8 resulted in a smaller [Ca(2+)](c) peak response, a faster rate of decay of [Ca(2+)](c) and lower values for the steady state of [Ca(2+)](c), compared with the effect of CCK-8 alone. Melatonin also reduced the oscillatory pattern of Ca(2+) mobilization evoked by a physiological concentration of CCK-8 (20 pM), and completely inhibited Ca(2+) mobilization induced by 10 pM CCK-8. On the other hand, Ca(2+) entry from the extracellular space was not affected in the presence of melatonin. Finally, melatonin alone did not change cell viability. We conclude that melatonin, at concentrations higher than those found in blood, might regulate exocrine pancreatic function via modulation of Ca(2+) signals.
authors.affiliation: Department of Physiology (Cell Physiology Research Group), University of Extremadura, Avenida Universidad s/n, 10003, Caceres, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Santofimia-Castaño
authors.forename: Deborah Clea
authors.initials: DC
authors.lastname: Ruy
authors.forename: Ginés M
authors.initials: GM
authors.lastname: Salido
authors.forename: Antonio
authors.initials: A
authors.lastname: González
mesh_terms: D061354:Acinar Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000681:Amylases / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D005456:Fluorescent Dyes; D016257:Fura-2; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D051379:Mice; D008856:Microscopy, Fluorescence; D046790:Pancreas, Exocrine / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D061251:Primary Cell Culture; D012844:Sincalide / Q000494:pharmacology*
chemical_list: D005456:Fluorescent Dyes; D000681:Amylases; D008550:Melatonin; D012844:Sincalide; D002118:Calcium; D016257:Fura-2
references.citation: J Physiol Pharmacol. 2007 Dec;58 Suppl 6:65-80
references.pmid: 18212401
references.citation: J Pineal Res. 2006 Apr;40(3):195-203
references.pmid: 16499554
references.citation: Curr Opin Gastroenterol. 2010 Sep;26(5):478-83
references.pmid: 20625287
references.citation: Dig Dis Sci. 2010 Apr;55(4):941-6
references.pmid: 19399617
references.citation: Biochem Biophys Res Commun. 1999 Aug 11;261(3):726-33
references.pmid: 10441493
references.citation: Gen Pharmacol. 1994 Sep;25(5):843-50
references.pmid: 7835627
references.citation: J Physiol Pharmacol. 2006 Nov;57 Suppl 5:83-96
references.pmid: 17218761
references.citation: J Pineal Res. 2011 Aug;51(1):17-43
references.pmid: 21517957
references.citation: Pancreatology. 2012 May-Jun;12(3):257-63
references.pmid: 22687382
references.citation: Mech Ageing Dev. 2011 Nov-Dec;132(11-12):573-82
references.pmid: 22024129
references.citation: Clin Exp Pharmacol Physiol. 2010 Oct;37(10):980-8
references.pmid: 20626416
references.citation: Biochem Biophys Res Commun. 1997 Jan 23;230(3):652-6
references.pmid: 9015379
references.citation: Curr Opin Gastroenterol. 2006 Sep;22(5):498-504
references.pmid: 16891880
references.citation: Cell Calcium. 1986 Feb;7(1):1-12
references.pmid: 2420465
references.citation: J Physiol Pharmacol. 2010 Oct;61(5):523-31
references.pmid: 21081795
references.citation: Endocr Rev. 2003 Oct;24(5):571-99
references.pmid: 14570743
references.citation: J Pineal Res. 2003 Jan;34(1):40-52
references.pmid: 12485371
references.citation: Nature. 1983 Nov 3-9;306(5938):67-9
references.pmid: 6605482
references.citation: J Pineal Res. 2010 Oct;49(3):248-55
references.pmid: 20626591
references.citation: J Pineal Res. 2004 Apr;36(3):155-64
references.pmid: 15009505
references.citation: J Pineal Res. 2012 Nov;53(4):390-8
references.pmid: 22672634
references.citation: J Physiol Biochem. 2001 Dec;57(4):331-9
references.pmid: 12005036
references.citation: Int J Biochem Cell Biol. 2010 Nov;42(11):1757-61
references.pmid: 20637894
references.citation: J Pineal Res. 2008 Oct;45(3):318-27
references.pmid: 18363673
references.citation: BMC Cell Biol. 2009 Oct 30;10:77
references.pmid: 19878551
references.citation: Physiol Rev. 1991 Jan;71(1):129-53
references.pmid: 1986387
references.citation: J Biol Chem. 1985 Mar 25;260(6):3440-50
references.pmid: 3838314
references.citation: Pharmacol Rep. 2010 Sep-Oct;62(5):864-73
references.pmid: 21098869
references.citation: J Pineal Res. 2010 Oct;49(3):256-63
references.pmid: 20626590
references.citation: Wien Med Wochenschr. 2008;158(19-20):575-8
references.pmid: 18998076
references.citation: J Pineal Res. 2011 Apr;50(3):250-60
references.pmid: 21118301
references.citation: Turk J Gastroenterol. 2010 Dec;21(4):433-8
references.pmid: 21331999
references.citation: Pancreas. 2011 Apr;40(3):410-4
references.pmid: 21178648
references.citation: Dig Dis Sci. 1999 Nov;44(11):2257-62
references.pmid: 10573371
references.citation: J Biol Chem. 1982 May 25;257(10):5554-9
references.pmid: 6175629