Histamine and histidine decarboxylase are hallmark features of ECL cells but not G cells in rat stomach

• The oxyntic mucosa of the rat stomach is rich in ECL cells which produce and secrete histamine in response to gastrin. Histamine and the histamine-forming enzyme histidine decarboxylase (HDC) have been claimed to occur also in the gastrin-secreting G cells in the antrum. In the present study, we used a panel of five HDC antisera and one histamine antiserum to investigate whether histamine and HDC are exclusive to the ECL cells. By immunocytochemistry, we could show that the ECL cells were stained with the histamine antiserum and all five HDC antisera. The G cells, however, were not stained with the histamine antiserum, but with three of the five HDC antisera. Thus, histamine and HDC coexist in the ECL cells (oxymic mucosa) but not in G cells (antral mucosa). Western blot analysis revealed a typical pattern of HDC-immunoreactive bands (74, 63 and 54 kDa) in oxymic mucosa extracts with all five antisera. In antral extracts, immunoreactive bands were detected with three of the five HDC antisera (same as above); the pattern of immunoreactivity differed from that in oxymic mucosa. Food intake or treatment with the proton pump inhibitor omeprazole raised the HDC activity and the HDC protein content of the oxyntic mucosa but not of the antral mucosa; the HDC activity in the antrum was barely detectable. We suggest that the HDC-like immunoreactivity in the antrum represents a cross-reaction with non-HDC proteins and conclude that histamine and HDC are hallmark features of ECL cells but not of G cells. (C) 2003 Elsevier B.V. All rights reserved.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Cell- och molekylärbiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Cell and Molecular Biology (hsv//eng)

Nyckelord

histidine decarboxylase (HDC)

histamine

ECL cells

G cells

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art (ämneskategori)

ref (ämneskategori)