The sulphonylurea receptor confers diazoxide sensitivity on the inwardly rectifying K+ channel Kir6.1 expressed in human embryonic kidney cells.

Journal article

1. We have examined the effects of diazoxide and intracellular ATP (ATPi) on whole-cell currents in HEK293 cells transfected transiently with the inwardly rectifying K+ channel Kir6.1 (uKATP1) or cotransfected with Kir6.1 and the sulphonylurea receptor (SUR1). 2. Kir6.1 currents were unaffected by the K+ channel opener diazoxide or by dialysis with 0.3 mM ATPi. 3. Kir6.1-SUR1 currents increased in amplitude when cells were dialysed with 0.3 mM ATP, but not with 5 mM ATP. This activation may be explained by the loss of endogenous ATP from the cell when the intracellular solution contains 0.3 mM ATP. Kir6.1-SUR1 currents were also activated by diazoxide; this activation was greater with 0.3 mM ATP1 than with 5 mM ATP1. 4. We conclude that SUR1 is required to confer both diazoxide and ATP sensitivity on Kir6.1.

Authors: Ammälä, C; Moorhouse, A; Ashcroft, F

• Publication status: Published
• Journal: Journal of physiology
• Volume: 494 ( Pt 3)
• Issue: 3
• Pages: 709-714
• Publication date: 1996-08-01
• EISSN: 1469-7793
• ISSN: 0022-3751
• Language: English
• Keywords: Adenosine Triphosphate; Diazoxide; Humans; Potassium Channels; Tolbutamide; Patch-Clamp Techniques; Kidney