Endocrinology, Vol 125, 1617-1622, Copyright © 1989 by Endocrine Society

ARTICLES

Pancreastatin, a presumed product of chromogranin-A (secretory protein- I) processing, inhibits secretion from porcine parathyroid cells in culture

BH Fasciotto, SU Gorr, DJ DeFranco, MA Levine and DV Cohn
Department of Oral Health, University of Louisville, Kentucky 40292.

Chromogranin-A, also referred to as secretory protein-I, is a 50K protein found in and secreted by endocrine cells, in which it is costored with the native hormone. Porcine chromogranin-A contains a sequence identical to pancreastatin, a 49-amino acid, C-terminally amidated peptide that has been isolated from porcine pancreas, suggesting that chromogranin-A is the precursor of pancreastatin. Pancreastatin has been found to be a potent inhibitor of glucose- stimulated insulin release. As it is possible that pancreastatin inhibits secretion from other chromogranin-A-containing tissues in which it may be formed, we tested its action on dispersed porcine parathyroid cells in culture. Secretion of chromogranin-A and PTH was up to 6-fold greater at 0.5 mM Ca2+ than at 3.0 mM Ca2+. Pancreastatin (1 nM) reduced the secretion of both chromogranin-A and PTH at 0.5 mM Ca2+ to approximately the levels found at 3.0 mM Ca2+, but did not affect secretion at 3.0 mM Ca2+. Pancreastatin (0.01-1.0 nM) inhibited secretion of chromogranin-A in a dose-dependent fashion. Preincubation of the cells with pancreastatin was not required for inhibition. Transfer of inhibited cells to medium without pancreastatin led to restoration of secretion within 90 min. Phorbol myristate acetate (1.6 microM) stimulated secretion of PTH and chromogranin-A at 3.0 mM Ca2+, but not at 0.5 mM Ca2+. Pancreastatin reversed this stimulation, demonstrating that its inhibition was independent of Ca2+ concentration. These results are consonant with pancreastatin playing a physiological role in modulation of secretion by the parathyroid and, by extension, other endocrine tissues.

This article has been cited by other articles:

				J. Huan, K. Olgaard, L. B. Nielsen, and E. Lewin Parathyroid Hormone 7-84 Induces Hypocalcemia and Inhibits the Parathyroid Hormone 1-84 Secretory Response to Hypocalcemia in Rats with Intact Parathyroid Glands J. Am. Soc. Nephrol., July 1, 2006; 17(7): 1923 - 1930. [Abstract] [Full Text] [PDF]

				V. Turquier, H. Vaudry, S. Jégou, and Y. Anouar Frog Chromogranin A Messenger Ribonucleic Acid Encodes Three Highly Conserved Peptides. Coordinate Regulation of Proopiomelanocortin and Chromogranin A Gene Expression in the Pars Intermedia of the Pituitary During Background Color Adaptation Endocrinology, September 1, 1999; 140(9): 4104 - 4112. [Abstract] [Full Text]

				E. Soliman, L. Canaff, J. Fox, and G. N. Hendy In Vivo Regulation of Chromogranin A Messenger Ribonucleic Acid in the Parathyroid by 1,25-Dihydroxyvitamin D: Studies in Normal Rats and in Chronic Renal Insufficiency Endocrinology, June 1, 1997; 138(6): 2596 - 2600. [Abstract] [Full Text] [PDF]

				J.-M. Strub, O. Sorokine, A. Van Dorsselaer, D. Aunis, and M.-H. Metz-Boutigue Phosphorylation and O-Glycosylation Sites of Bovine Chromogranin A from Adrenal Medullary Chromaffin Granules and Their Relationship with Biological Activities J. Biol. Chem., May 2, 1997; 272(18): 11928 - 11936. [Abstract] [Full Text] [PDF]

				V. Sanchez-Margalet and J. Santos-Alvarez Solubilization and Molecular Characterization of Active Pancreastatin Receptors from Rat Liver Membranes Endocrinology, April 1, 1997; 138(4): 1712 - 1718. [Abstract] [Full Text] [PDF]