Coexpression of mineralocorticoid receptors and 11 β-hydroxysteroid dehydrogenase 2 in human gastric mucosa

Katsuaki Kato, Hironobu Sasano, Shuichi Ohara, Hitoshi Sekine, Shizue Mochizuki, Tomoatsu Mune, Keigo Yasuda, Hiroshi Nagura, Tooru Shimosegawa, Takayoshi Toyota, Zygmunt Krozowski

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The role of mineralocorticoids in human gastrointestinal tract is well established. In the stomach, aldosterone is thought to regulate electrolyte transport associated with gastric acid secretion. In mineralocorticoid target organs, the action of the glucocorticoid inactivating enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) facilitates aldosterone binding to a nonselective mineralocorticoid receptor (MR) in the face of high levels of circulating glucocorticoids. In the present study, we examined 25 specimens of human stomach for the presence of MR and 11β-HSD2 using a [3H]aldosterone binding assay, Northern blot analysis, RT-PCR, and immunohistochemistry. Specific [3H]aldosterone binding sites were detected in gastric fundic mucosa, but not in the antrum. In fundic mucosa the K(d) was 0.72 ±0.05 nmol/L (mean ± SE), and B(max) was 6.0 ± 1.4 fmol per milligram of protein. Northern blot analysis demonstrated a faint band for MR mRNA at 6.0 kb, although message for 11β-HSD2 was undetectable. However, RT-PCR demonstrated specific PCR products for both MR and 11β-HSD2. Immunohistochemistry demonstrated the colocalization of MR and 11β-HSD2 only in parietal cells. MR-positive cells were further characterized by electron microscopy, confirming the identity of parietal cells. This study shows that parietal cells contain both MR and 11β-HSD2, suggesting that the human stomach is a novel target organ for mineralocorticoids. Aldosterone may, therefore, regulate biological functions of parietal cells including gastric acid secretion.

Original languageEnglish
Pages (from-to)2568-2573
Number of pages6
JournalJournal of Clinical Endocrinology and Metabolism
Volume84
Issue number7
DOIs
Publication statusPublished - 1999

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Endocrinology
  • Clinical Biochemistry
  • Biochemistry, medical

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