Regulatory volume increase in rat pancreatic beta-cells.
This study investigated regulatory volume increase (RVI) in rat pancreatic beta-cells. Volume changes in isolated beta-cells were measured by a video-imaging method. Cell shrinkage was induced by exposure to solutions made hypertonic by the addition of 100 mM mannitol. In HEPES-buffered solutions, beta-cells exhibited an RVI which was almost completely abolished by 10 microM bumetanide. These data indicate that Na+-2Cl--K+ cotransporters make a major contribution to RVI in beta-cells. In HCO3--buffered solutions, however, an RVI was observed in the presence of 10 microM bumetanide. This bumetanide-insensitive component of RVI was inhibited by 100 microM amiloride or 100 microM 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS). These data suggest that, in addition to the Na+-2Cl--K+ cotransporter, functionally coupled Na+-H+ exchangers and Cl--HCO3- exchangers may also contribute to RVI in pancreatic beta-cells.
Miley
H E
HE
Cell Physiology Group, School of Biological Sciences, Stopford Building, University of Manchester, Manchester M13 9PT, UK.
Holden
D
D
Grint
R
R
Best
L
L
Brown
P D
PD
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001639:Bicarbonates; D002021:Buffers; D002034:Bumetanide / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism; D048429:Cell Size; D004232:Diuretics / Q000494:pharmacology; D006982:Hypertonic Solutions; D007515:Islets of Langerhans / Q000166:cytology*; D008297:Male; D008353:Mannitol / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D028021:Sodium-Potassium-Chloride Symporters; D012996:Solutions; D014741:Video Recording
D001639:Bicarbonates; D002021:Buffers; D002352:Carrier Proteins; D004232:Diuretics; D006982:Hypertonic Solutions; D028021:Sodium-Potassium-Chloride Symporters; D012996:Solutions; D002034:Bumetanide; D008353:Mannitol; D000584:Amiloride; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid