title: Congo red modulates ACh-induced Ca(2+) oscillations in single pancreatic acinar cells of mice.
abstract: OBJECTIVE
  Congo red, a secondary diazo dye, is usually used as an indicator for the presence of amyloid fibrils. Recent studies show that congo red exerts neuroprotective effects in a variety of models of neurodegenerative diseases. However, its pharmacological profile remains unknown. In this study, we investigated the effects of congo red on ACh-induced Ca(2+) oscillations in mouse pancreatic acinar cells in vitro.
  
  
  METHODS
  Acutely dissociated pancreatic acinar cells of mice were prepared. A U-tube drug application system was used to deliver drugs into the bath. Intracellular Ca(2+) oscillations were monitored by whole-cell recording of Ca(2+)-activated Cl(-) currents and by using confocal Ca(2+) imaging. For intracellular drug application, the drug was added in pipette solution and diffused into cell after the whole-cell configuration was established.
  
  
  RESULTS
  Bath application of ACh (10 nmol/L) induced typical Ca(2+) oscillations in dissociated pancreatic acinar cells. Addition of congo red (1, 10, 100 μmol/L) dose-dependently enhanced Ach-induced Ca(2+) oscillations, but congo red alone did not induce any detectable response. Furthermore, this enhancement depended on the concentrations of ACh: congo red markedly enhanced the Ca(2+) oscillations induced by ACh (10-30 nmol/L), but did not alter the Ca(2+) oscillations induced by ACh (100-10000 nmol/L). Congo red also enhanced the Ca(2+) oscillations induced by bath application of IP3 (30 μmol/L). Intracellular application of congo red failed to alter ACh-induced Ca(2+) oscillations.
  
  
  CONCLUSIONS
  Congo red significantly modulates intracellular Ca(2+) signaling in pancreatic acinar cells, and this pharmacological effect should be fully considered when developing congo red as a novel therapeutic drug.
authors.affiliation: 1] Department of Infectious Diseases, Xiangya Hospital, Central South University, and Key Laboratory of Viral Hepatitis, Changsha 410008, China [2] Divisions of Neurology and Neurobiology, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ 8501, USA [3] Departments of Basic Medical Sciences, Pharmacology and Psychiatry, University of Arizona College of Medicine, Phoenix, AZ 85004, USA.
authors.forename: Ze-bing
authors.initials: ZB
authors.lastname: Huang
authors.affiliation: Department of Physiology, Shantou University of Medical College, Shantou 210854, China.
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Wang
authors.affiliation: Department of Physiology, Shantou University of Medical College, Shantou 210854, China.
authors.forename: Na-na
authors.initials: NN
authors.lastname: Sun
authors.affiliation: Department of Physiology, Shantou University of Medical College, Shantou 210854, China.
authors.forename: Jing-ke
authors.initials: JK
authors.lastname: Wang
authors.affiliation: Department of Physiology, Shantou University of Medical College, Shantou 210854, China.
authors.forename: Meng-qin
authors.initials: MQ
authors.lastname: Zhao
authors.affiliation: Department of Physiology, Shantou University of Medical College, Shantou 210854, China.
authors.forename: Jian-xin
authors.initials: JX
authors.lastname: Shen
authors.affiliation: Divisions of Neurology and Neurobiology, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ 8501, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Gao
authors.affiliation: Departments of Basic Medical Sciences, Pharmacology and Psychiatry, University of Arizona College of Medicine, Phoenix, AZ 85004, USA.
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Hammer
authors.affiliation: Department of Infectious Diseases, Xiangya Hospital, Central South University, and Key Laboratory of Viral Hepatitis, Changsha 410008, China.
authors.forename: Xue-gong
authors.initials: XG
authors.lastname: Fan
authors.affiliation: 1] Department of Infectious Diseases, Xiangya Hospital, Central South University, and Key Laboratory of Viral Hepatitis, Changsha 410008, China [2] Divisions of Neurology and Neurobiology, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ 8501, USA [3] Department of Physiology, Shantou University of Medical College, Shantou 210854, China [4] Departments of Basic Medical Sciences, Pharmacology and Psychiatry, University of Arizona College of Medicine, Phoenix, AZ 85004, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects*; D003224:Congo Red / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials; D051379:Mice; D046790:Pancreas, Exocrine / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors
chemical_list: D002121:Calcium Channel Blockers; D003224:Congo Red; D015544:Inositol 1,4,5-Trisphosphate; D000109:Acetylcholine