| First Author | Pasham V | Year | 2013 |
| Journal | Cell Physiol Biochem | Volume | 32 |
| Issue | 6 | Pages | 1643-54 |
| PubMed ID | 24334852 | Mgi Jnum | J:330504 |
| Mgi Id | MGI:6852072 | Doi | 10.1159/000356600 |
| Citation | Pasham V, et al. (2013) Annexin 7 in the regulation of gastric acid secretion. Cell Physiol Biochem 32(6):1643-54 |
| abstractText | BACKGROUND/AIMS: Glucocorticoids enhance gastric acid secretion and inhibit gastric cyclooxygenase, thus downregulating formation of PGE2, an inhibitor of gastric acid secretion. In erythrocytes, PGE2 formation is inhibited by annexin 7. The present study thus explored whether annexin 7 participates in the regulation of gastric acid secretion. METHODS: Annexin 7 protein expression was determined by Western blotting, cytosolic pH (pHi) of parietal cells utilizing BCECF-fluorescence, and gastric acid secretion by determination of Na(+)-independent pHi recovery from an ammonium pulse (pHi/min). Experiments were performed in isolated glands from gene targeted mice lacking annexin 7 (anx7(-/-)) and in respective wild type animals (anx7(+/+)). RESULTS: Prior to treatment pHi and pHi/min were similar in isolated gastric glands from anx7(-/-) and from anx7(+/+) mice. Aspirin (100 microM added to the glands 1 hr prior to the experiment) significantly increased pHi/min to similar values in both genotypes. The administration of dexamethasone (10 microg/g BW subcutaneously for 4 consecutive days prior to the experiments) significantly increased pH/min in anx7(+/+) mice but not in anx7(-/-) mice. Following dexamethasone treatment, the luminal pH was significantly lower and the acid content significantly higher in anx7(+/+) mice than in anx7(-/-) mice. An increase of extracellular K(+) concentration to 35 mM (replacing Na(+)/NMDG(+)) significantly increased pHi/min in both genotypes. In neither genotype dexamethasone increased pH/min further in the presence of 35 mM K(+) or presence of aspirin. CONCLUSIONS: Annexin 7 is required for the stimulation of gastric acid secretion by glucocorticoids. |
