Neuroendocrine (ECL cell) differentiation of spontaneous gastric carcinomas of cotton rats (Sigmodon hispidus).
OBJECTIVE
Female inbred cotton rats develop adenocarcinomas in the oxyntic mucosa. Since a female preponderance is typical for enterochromaffin-like (ECL) cell tumors, we examined such tumors for ECL cells. Gastrin plays a decisive role in ECL cell tumorigenesis, so blood gastrin concentration and gastric mucosal pH were measured.


METHODS
The stomachs from six female cotton rats (6 to 8 months old) were studied histologically, and at euthanasia, gastric mucosal pH was determined. Euthanasia was performed on 15 other female cotton rats of similar age for determination of blood gastrin values by radioimmunoassay (RIA) and gastric mucosal pH. Rats were classified macroscopically to have normal or thick oxyntic mucosa, with or without tumor.


RESULTS
Among the six cotton rats studied histologically, two 6-month-old rats had normal and two others had thick gastric mucosa, whereas two 8-month-old rats had thick mucosa with tumors. The ECL cells were markedly hyperplastic in all rats with thick mucosa, and ECL cells were found in the neoplastic parenchyma. All cotton rats with normal-appearing gastric mucosa had pH <2.5, whereas 14 rats with thick mucosa had pH >3.1 and hypergastrinemia.


CONCLUSIONS
Gastrin may play a major role in ECL cell hyperplasia and, perhaps, in adenocarcinoma genesis.
Department of Medicine, University Hospital, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim.
H L
HL
Waldum
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Rørvik
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S
Falkmer
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Kawase
D000230:Adenocarcinoma / Q000737:chemistry / Q000473:pathology / Q000662:veterinary*; D000818:Animals; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis; D004759:Enterochromaffin Cells / Q000737:chemistry / Q000473:pathology* / Q000502:physiology; D005260:Female; D005755:Gastrins / Q000097:blood; D006640:Histidine Decarboxylase / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D006965:Hyperplasia / Q000473:pathology / Q000662:veterinary; D007124:Immunoenzyme Techniques / Q000662:veterinary; D008297:Male; D011863:Radioimmunoassay / Q000662:veterinary; D051381:Rats; D012376:Rodent Diseases / Q000473:pathology*; D016205:Sigmodontinae; D013274:Stomach Neoplasms / Q000737:chemistry / Q000473:pathology / Q000662:veterinary*; D016708:Synaptophysin / Q000032:analysis
D053379:Chromogranin A; D002864:Chromogranins; D005755:Gastrins; D016708:Synaptophysin; D006640:Histidine Decarboxylase