Effect of cysteamine on gastric nerve fibers containing gastrin-releasing peptide in the rat.
In rats, changes in gastric nerve fibers containing gastrin-releasing peptide (GRP) in cysteamine-induced duodenal ulcer were investigated in relation to the dynamics of gastrin-producing cells (G-cells). Marked increases in gastric acid secretion and serum gastrin level were observed from 2 h after the administration of cysteamine. The number of G-cells was significantly decreased from 2 h after the injection of cysteamine. Two and 4 h after the administration of cysteamine, the G-cells showed ultrastructural changes characterized by a markedly decreased number of secretory granules. Circulating GRP levels were significantly elevated from 2 h after the administration of cysteamine. In the control group given vehicle only, nerve fibers showing immunoreaction for GRP formed a fine network in the gastric wall and were densely distributed in the oxyntic mucosa, located close to capillaries and demonstrated varicosities that contained either small clear vesicles or GRP-immunopositive vesicles with large cores. Eight h after the administration of cysteamine, there was depleted GRP immunoreactivity, evidenced by a markedly decreased number of vesicles, with large electron-dense cores, in the oxyntic mucosa. These findings suggest that, in cysteamine-induced duodenal ulcer, alterations in gastric nerve fibers containing GRP may be related to hypergastrinemia.
Shimoda
H
H
First Department of Anatomy, Oita Medical University, Japan.
Takeno
S
S
Noguchi
T
T
Uchida
Y
Y
Usui
T
T
Takeyama
M
M
D000818:Animals; D002452:Cell Count; D003543:Cysteamine / Q000494:pharmacology* / Q000633:toxicity; D004381:Duodenal Ulcer / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D005500:Follow-Up Studies; D005744:Gastric Acid / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D019886:Gastrin-Releasing Peptide; D005755:Gastrins / Q000096:biosynthesis / Q000187:drug effects; D007150:Immunohistochemistry; D008297:Male; D016253:Microscopy, Immunoelectron; D009412:Nerve Fibers / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D010455:Peptides / Q000187:drug effects / Q000378:metabolism*; D011837:Radiation-Protective Agents / Q000494:pharmacology* / Q000633:toxicity; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000187:drug effects / Q000294:innervation*
D005755:Gastrins; D010455:Peptides; D011837:Radiation-Protective Agents; D003543:Cysteamine; C013550:gastrin 17; D019886:Gastrin-Releasing Peptide