ID 111481
Author
Shitara, Akiko University of Hokkaido
Tanimura, Akihiko University of Hokkaido
Sato, Atsuko Fukuoka Dental College
Tojyo, Yosuke University of Hokkaido
Keywords
salivary duct
spontaneous Ca2+ oscillation
purinergic receptors
cell swelling
Content Type
Journal Article
Description
Rat parotid ductal cells were found to exhibit spontaneous Ca2+ oscillations. These oscillatory Ca2+ responses were observed during continuous perfusion with physiological salt solution at 37℃ in the absence of calcium mobilizing agonist stimulation. These Ca2+ oscillations were completely blocked by the purinergic receptor inhibitors, pyridoxal phosphate-6-azo (benzene-2,4-disulfonic acid) (PPADS) and suramin, but were not blocked by the muscarinic antagonist, atropine, nor the α-adrenergic antagonist, phentolamine. Simultaneous observation with fura-2 fluorescence and differential interference contrast (DIC) images showed that the spontaneous elevations of [Ca2+]i were well correlated with the shape changes of the ductal cells. Using a plasma membrane fluorescence probe, we found that the changes in DIC images reflected spontaneous cell swelling of ductal cells. Electron microscopic analysis after Ca2+ imaging indicated that the spontaneously oscillating duct cells contained numerous granules at the luminal side, which is characteristic of the granular duct cells. These results indicate that the spontaneous [Ca2+]i increase occurs through purinergic receptors, and activates Ca2+-dependent ion transporters and/or channels. Our findings present the possibility that spontaneous Ca2+ oscillations via purinergic receptors are involved in the regulation of the electrolyte composition of saliva in resting states.
Journal Title
The Journal of Medical Investigation
ISSN
13496867
13431420
NCID
AA11166929
AA12022913
Publisher
Faculty of Medicine Tokushima University
Volume
56
Issue
Supplement
Start Page
377
End Page
380
Sort Key
377
Published Date
2009-12
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Publisher