| First Author | Louchami K | Year | 2012 |
| Journal | Cell Physiol Biochem | Volume | 29 |
| Issue | 1-2 | Pages | 65-74 |
| PubMed ID | 22415076 | Mgi Jnum | J:323082 |
| Mgi Id | MGI:6855041 | Doi | 10.1159/000337588 |
| Citation | Louchami K, et al. (2012) A new role for aquaporin 7 in insulin secretion. Cell Physiol Biochem 29(1-2):65-74 |
| abstractText | UNLABELLED: BACGROUNS/AIMS: Several insulinotropic agents were recently reported to cause beta-cell swelling. The possible participation of AQP7 to water transport was investigated in AQP7(+/+) or AQP7(-/-) mice. METHODS: Aquaporin expression, insulin secretion, cell swelling and electrical activity were investigated in pancreatic islets. RESULTS: RT-PCR revealed the expression of AQP5 and AQP8 mRNA. Double immunofluorescent labeling indicated their presence in beta-cells. Whilst basal insulin release from isolated pancreatic islets incubated at 2.8 mM D-glucose did not differ between AQP7(+/+) or AQP7(-/-) mice, the secretion of insulin evoked by the omission of 50 mM NaCl, the substitution of 50 mM NaCl by 100 mM glycerol or a rise in D-glucose concentration to 8.3 mM and 16.7 mM was severely impaired in the islets from AQP7(-/-) mice. Yet, exposure of beta-cells to either the hypotonic medium or a rise in D-glucose concentration caused a similar degree of swelling and comparable pattern of electrical activity in cells from AQP7(+/+) and AQP7(-/-) mice. Both the cell swelling and change in membrane potential were only impaired in AQP7(-/-) cells when exposed to 50 mM glycerol. CONCLUSION: It is proposed, therefore, that AQP7 may, directly or indirectly, play a role at a distal site in the exocytotic pathway. |
