Cell-specific processing of chromogranin A in endocrine cells of the rat stomach.
The rat stomach is rich in endocrine cells. The acid-producing (oxyntic) mucosa contains ECL cells, A-like cells, and somatostatin (D) cells, and the antrum harbours gastrin (G) cells, enterochromaffin (EC) cells and D cells. Although chromogranin A (CgA) occurs in all these cells, its processing appears to differ from one cell type to another. Eleven antisera generated to different regions of rat CgA, two antisera generated to a human (h) CgA sequences, and one to a bovine (b) CgA sequence, respectively, were employed together with antisera directed towards cell-specific markers such as gastrin (G cells), serotonin (EC cells), histidine decarboxylase (ECL cells) and somatostatin (D cells) to characterize the expression of CgA and CgA-derived peptides in the various endocrine cell populations of the rat stomach. In the oxyntic mucosa, antisera raised against CgA(291-319) and CGA(316-321) immunostained D cells exclusively, whereas antisera raised against bCgA(82-91) and CgA(121-128) immunostained A-like cells and D cells. Antisera raised against CgA(318-349) and CgA(437-448) immunostained ECL cells and A-like cells, but not D cells. In the antrum, antisera against CgA(291-319) immunostained D cells, and antisera against CgA(351-356) immunostained G cells. Our observations suggest that each individual endocrine cell type in the rat stomach generates a unique mixture of CgA-derived peptides, probably reflecting cell-specific differences in the post-translational processing of CgA and its peptide products. A panel of antisera that recognize specific domains of CgA may help to identify individual endocrine cell populations.
Norlén
P
P
Department of Pharmacology, Institute of Physiological Sciences, University of Lund, Sweden.
Curry
W J
WJ
Björkqvist
M
M
Maule
A
A
Cunningham
R T
RT
Hogg
R B
RB
Harriott
P
P
Johnston
C F
CF
Hutton
J C
JC
Håkanson
R
R
D000818:Animals; D002417:Cattle; D053379:Chromogranin A; D002864:Chromogranins / Q000276:immunology / Q000378:metabolism*; D019858:Enteroendocrine Cells / Q000166:cytology / Q000378:metabolism*; D005629:Frozen Sections; D005753:Gastric Mucosa / Q000378:metabolism*; D019863:Gastrin-Secreting Cells / Q000378:metabolism; D006801:Humans; D007106:Immune Sera; D007150:Immunohistochemistry; D008297:Male; D010295:Parietal Cells, Gastric / Q000378:metabolism; D010446:Peptide Fragments / Q000276:immunology / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011706:Pyloric Antrum / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D019864:Somatostatin-Secreting Cells / Q000378:metabolism; D013270:Stomach / Q000166:cytology
C506150:CHGA protein, human; D053379:Chromogranin A; D002864:Chromogranins; D007106:Immune Sera; D010446:Peptide Fragments; C506153:chromogranin A, rat