Muscarinic receptor antagonist effects in parotid acini and M1-CHO cells: evidence of G protein involvement
Horn, V.J.; Baum, B.J.; Ambudkar, I.S.
Biochemical and Biophysical Research Communications 177(2): 784-789
1991
ISSN/ISBN: 0006-291X PMID: 1904723 Document Number: 368972
We have examined the effects of the muscarinic antagonist atropine, on non-receptor-mediated activation of intracellular calcium (Ca2+i) mobilization events. In dispersed rat parotid acini, atropine significantly lowered basal inositol trisphosphate levels and delayed AlF4--stimulated Ca2+i elevation in a dose-dependent manner. In a cell line transfected with the mi muscarinic receptor (M1-CHO), atropine significantly lowered (.apprxeq.60%)AlF4- stimulated Ca2+i elevation. The aggregate findings suggest that atropine, acting via the muscarinic receptor, decreases the efficacy of G protein-mediated activation of phopholipase C.