Back
Acta Physiologica 2013; Volume 207, Supplement 694
92nd Annual Meeting of the German Physiological Society
3/2/2013-3/5/2013
Heidelberg, Germany
ANNEXIN 7 IN THE REGULATION OF GASTRIC ACID SECRETION
Abstract number: O48
Chatterjee
1
*S.
, Pasham
1
V., Rotte
1
A., Mia
1
S., Alesutan
1
I., Hosseinzadeh
1
Z., Bhandaru
1
M., Noegel
2
A.A., Lang
1
F.
1
University of Tuebingen, Department of Physiology, Tuebingen, Germany
2
Medical Faculty, University of Cologne, Center for Biochemistry, Institute of Biochemistry I, Köln, Germany
Question:
Glucocorticoids enhance gastric acid secretion and decrease gastric 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 µM 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 µg/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.
To cite this abstract, please use the following information:
Acta Physiologica 2013; Volume 207, Supplement 694 :O48