Somatostatin stimulates intestinal NHE8 expression via p38 MAPK pathway

• DOI: 10.1152/ajpcell.00421.2010
• Publication Date: 2010-11-25T03:31:11Z
• Authors: Chunhui Wang; Hua Xu; Huacong Chen; Jing Li; Bo Zhang; Chengwei Tang; Fayez K. Ghishan
• Keywords: 0303 health sciences; Sodium-Hydrogen Exchangers; Microvilli; Sodium; Octreotide; p38 Mitogen-Activated Protein Kinases; Cell Line; 3. Good health; Mice; 03 medical and health sciences; Intestinal Absorption; Intestine, Small; Animals; Humans; Female; Receptors, Somatostatin; Caco-2 Cells; Phosphorylation; Antidiarrheals; Somatostatin; Oligopeptides

Diarrhea is a common manifestation of gastrointestinal disorders. Diarrhea-induced losses fluid and electrolyte could lead to dehydration imbalances, resulting in significant morbidity mortality, especially children living developing countries. Somatostatin, peptide hormone secreted by D-cells, plays an important role regulating motility intestinal Na(+) absorption. Although octreotide, somatostatin analog, used treat diarrhea, its mechanisms action are unclear. Here we showed that octreotide increased brush-border membrane Na(+)/H(+) exchanger 8 (NHE8) expression the small intestine exclusion other NHEs participate The same effect also occurred human cells (Caco-2). We found increase NHE8 required p38 mitogen-activated protein kinase (MAPK) activation. Furthermore, receptor SSTR2 antagonist CYN154806 abolish somatostatin-induced MAPK phosphorylation. Thus our data provided first concrete evidence indicating stimulates absorption increasing through SSTR2-p38 pathway.