Glucose-induced swelling in rat pancreatic alpha-cells.
Pancreatic beta-cells increase in volume when exposed to elevated concentrations of extracellular glucose. This study has examined the effects of glucose on the volumes of pancreatic alpha-cells, which like beta-cells are regulated by glucose, and intestinal epithelial Caco-2 cells which are unresponsive to glucose. Cell volume changes were monitored by a video-imaging method. Increasing the extracellular glucose concentration caused a concentration-dependent increase in alpha-cell volume over the range 1-20mM. Glucose-induced swelling was not, however, observed in Caco-2 cells. The glucose-induced swelling in both alpha- and beta-cells was abolished by 0.5mM phloretin, an inhibitor of the GLUT proteins, indicating that GLUT mediated glucose transport is a pre-requisite for swelling. Glucose metabolism also appears to be essential, as islet cell swelling was not observed with 16 mM 3-O-methyl glucose. These data suggest that glucose-induced swelling may be a property exclusive to glucose-regulated cells.
Davies
Sarah L
SL
Faculty of Life Sciences, University of Manchester, 2nd Floor Core Technology Facility, 46 Grafton Street, Manchester M13 9NT, United Kingdom.
Brown
Peter D
PD
Best
Len
L
D000818:Animals; D018938:Caco-2 Cells; D048429:Cell Size / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D050416:Glucagon-Secreting Cells / Q000166:cytology* / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D051246:Glucose Transport Proteins, Facilitative / Q000037:antagonists & inhibitors; D006801:Humans; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000378:metabolism; D010693:Phloretin / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013549:Sweetening Agents / Q000494:pharmacology*
D051246:Glucose Transport Proteins, Facilitative; D013549:Sweetening Agents; D005947:Glucose; D010693:Phloretin