Journal of Dental Research, Vol 70, 1524-1527, Copyright © 1991 by International & American Associations for Dental Research Online Journals

ARTICLES

Calcium uptake in rat parotid gland secretory granules

J. E. Porter, P. Cheung and F. J. Dowd
Department of Pharamcology, Creighton University School of Medicine, Omaha, Nebraska 68178.

45Ca2+ uptake in isolated rat parotid secretory granules was examined in the presence of oxalate. Uptake of calcium was dependent on time, with the maximum occurring at 15 min. The uptake of calcium was dependent on adenosine-5'-triphosphate (ATP), and substitution of ATP with beta, gamma-methylene-ATP did not stimulate calcium uptake. Enzyme marker analysis indicated that mitochondria accounted for no greater than 3.0 +/- 0.2% of the observed ATP-dependent calcium uptake. Calcium uptake was blocked by the ATPase inhibitors tributyltin, IC50 = 12.2 +/- 0.6 nmol/L and 4-acetamido-4'-isothiocyano-2,2'-stilbene disulphonic acid (SITS), IC50 = 3.0 +/- 0.3 mumol/L. These results indicate that in the parotid secretory granule there is a calcium uptake mechanism that is dependent on the hydrolysis of ATP and is suppressed by two inhibitors of granule ATPase.

This article has been cited by other articles:

				Y.J. Kim, J.M. An, D.M. Shin, S.-I. Lee, H. Sugiya, and J.T. Seo Staurosporine Mobilizes Ca2+ from Secretory Granules by Inhibiting Protein Kinase C in Rat Submandibular Acinar Cells J. Dent. Res., November 1, 2002; 81(11): 788 - 793. [Abstract] [Full Text] [PDF]