Similarities of K+ATP channel expression and Ca2+ changes in pancreatic beta cells and hypothalamic neurons.
The mechanisms through which pancreatic beta cells recognize and respond to changes in circulating glucose are well understood. Evidence is accumulating that a subpopulation of neurons in the ventromedial hypothalamus (VMH) use similar cellular mechanisms to sense changes in extracellular glucose. In the present study, we used PCR and single-cell calcium imaging techniques to investigate whether glucose-sensing cells in the pancreas and hypothalamus employ a similar set of stimulus-response elements. Dispersed cells from mouse pancreata and hypothalamus were used in conjunction with the insulin-secreting cell line MIN6. We present functional data suggesting that both pancreatic and a subpopulation of hypothalamic cells exhibit glucose- and tolbutamide-evoked changes in cytosolic calcium and consider some clinical implications of different glucose sensors using the same mechanisms.
Squires
Paul E
PE
Molecular Physiology, Department of Biological Sciences, University of Warwick, Coventry, United Kingdom. psquires@bio.warwick.ac.uk
Churamani
Dev
D
Pararajasingam
Rebecca
R
Persaud
Shanta J
SJ
Jones
Peter M
PM
D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D007004:Hypoglycemic Agents / Q000494:pharmacology; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics* / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D011955:Receptors, Drug; D064233:Sulfonylurea Receptors; D014044:Tolbutamide / Q000494:pharmacology; D014697:Ventromedial Hypothalamic Nucleus / Q000166:cytology* / Q000378:metabolism; D000099161:Kcnj11 Channel
D018528:ATP-Binding Cassette Transporters; D002118:Calcium; D005947:Glucose; D007004:Hypoglycemic Agents; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D024661:Potassium Channels, Inwardly Rectifying; D011189:Potassium Chloride; D012333:RNA, Messenger; D011955:Receptors, Drug; D064233:Sulfonylurea Receptors; D014044:Tolbutamide; D000099161:Kcnj11 Channel