Journal
CELLULAR SIGNALLING
Volume 19, Issue 10, Pages 2155-2164Publisher
ELSEVIER SCIENCE INC
DOI: 10.1016/j.cellsig.2007.06.012
Keywords
P2X(7) receptors; KO mice; purinergic; IL-1 beta; saliva; exocrine glands
Categories
Ask authors/readers for more resources
The effect of extracellular ATP on salivary gland function was compared in wild-type (WT) and P2X(7) knockout (KO) mice. The increase in the intracellular concentration of calcium ([Ca2+](i)) in response to carbachol was similar in submandibular ductal cells of WT and KO mice. ATP and its analog, benzoyl-ATP, induced a sustained increase in the [Ca2+](i) in WT animals. In KO mice, ATP slightly and transiently increased the [Ca2+](i) and benzoyl-ATP had no effect. The response to ATP of WT but not KO mice was blocked by KN-62, Coomassie blue and magnesium. The small response of ATP observed in KO mice was completely blocked in the absence of extracellular calcium, unchanged by U73122 and potentiated by ivermectin indicating the probable involvement of a P2X(4) receptor. A RT-PCR and a Western blot confirmed the presence of these receptors in ducts of both WT and KO mice. ATP increased the permeability of the cells to ethidium bromide and stimulated a phospholipase A(2) activity in WT but not KO mice. Mice submandibular gland cells secreted IL-1 beta but this secretion was not modified by ATP and was similar in both groups of animals. The volume of saliva provoked by pilocarpine and the concentration of proteins, sodium and chloride in this saliva was similar in both groups of animals. The concentration of potassium was higher in KO mice. We can conclude that the major purinergic receptors expressed in mice submandibular ductal cells are P2X7 receptors but that P2X4 receptors are also involved in some ATP effects. (c) 2007 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available