A New Role for Aquaporin 7 in Insulin Secretion
Autor: | Olivier Devuyst, Christine Delporte, Jason Perret, Renaud Beauwens, Peter de Nully Brown, Emeline Hupkens, Shinichi Uchida, Willy Malaisse, Abdullah Sener, Myrna Virreira, L. Best, Karim Louchami |
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Přispěvatelé: | University of Zurich, Louchami, Karim |
Rok vydání: | 2012 |
Předmět: |
Glycerol
Male medicine.medical_specialty Physiology Aquaporin 610 Medicine & health Sodium Chloride Biology Aquaporins Membrane Potentials 10052 Institute of Physiology Mice Insulin-Secreting Cells Internal medicine Insulin Secretion medicine Animals Insulin 10035 Clinic for Nephrology Insulin secretion Cell Size Mice Knockout Cell swelling Distal site 1314 Physiology Aquaporin 5 Glucose Endocrinology 10076 Center for Integrative Human Physiology 570 Life sciences biology Female Insulin metabolism |
Zdroj: | Cellular Physiology and Biochemistry. 29:65-74 |
ISSN: | 1421-9778 1015-8987 |
Popis: | BACGROUNS/AIMS: Several insulinotropic agents were recently reported to cause β-cell swelling. The possible participation of AQP7 to water transport was investigated in AQP7(+/+) or AQP7(-/-) mice.Aquaporin expression, insulin secretion, cell swelling and electrical activity were investigated in pancreatic islets.RT-PCR revealed the expression of AQP5 and AQP8 mRNA. Double immunofluorescent labeling indicated their presence in β-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 β-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.It is proposed, therefore, that AQP7 may, directly or indirectly, play a role at a distal site in the exocytotic pathway. |
Databáze: | OpenAIRE |
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