Effects of antioxidants on calcium signal induced by cholecystokinin in mouse pancreatic acinar cells.
Digital imaging fluorescence microscopy was used to study the effect of two antioxidants, N-acetyl-cysteine (NAC) and glutathione, on the cytosolic free calcium concentration ([Ca2+]i) induced by cholecystokinin-octapeptide (CCK-8) of mouse pancreatic acinar cells. When acinar cells were preincubated with either NAC or glutathione, subsequent stimulation with CCK-8 in the presence of each antioxidant had no significant effect on the typical pattern of [Ca2+]i transient evoked by the gastrointestinal hormone. However, application of NAC to acinar cells pretreated for 60 min with the same antioxidant, strongly blocked the oscillatory pattern initiated by CCK-8, inhibiting both amplitude and frequency of calcium oscillations. By contrast, glutathione had no effect on the oscillatory pattern evoked by CCK-8. The present results allow us to speculate that during [Ca2+]i oscillation there is a production of oxidants that facilitate oscillations by enhancing release of calcium from internal stores.
Camello
C
C
Department of Physiology, Faculty of Veterinary Sc, University of Extremadura, Cáceres, Spain.
Camello
P J
PJ
Pariente
J A
JA
Salido
G M
GM
D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005978:Glutathione / Q000494:pharmacology; D066298:In Vitro Techniques; D051379:Mice; D010179:Pancreas / Q000166:cytology* / Q000187:drug effects; D012844:Sincalide / Q000494:pharmacology*
D000975:Antioxidants; D016166:Free Radical Scavengers; D005978:Glutathione; D012844:Sincalide; D002118:Calcium; D000111:Acetylcysteine