Related Experiment Videos
Sulphonylurea action revisited: the post-cloning era
1Department of Clinical Biochemistry, Addenbrooke's Hospital, Hills Road, Box 232, Cambridge CB2 2QR, UK. fmg23@cam.ac.uk
Diabetologia
|June 24, 2003
Summary
Hypoglycaemic drugs like sulphonylureas and glinides target ATP-sensitive potassium (K(ATP)) channels. Differences in drug selectivity for pancreatic versus extrapancreatic K(ATP) channels influence potential side effects.
Area of Science:
- Pharmacology
- Molecular Biology
- Endocrinology
Background:
- Hypoglycaemic agents, including sulphonylureas and glinides, function by inhibiting ATP-sensitive potassium (K(ATP)) channels in pancreatic beta cells to stimulate insulin secretion.
- These drugs exhibit variable cross-reactivity with K(ATP) channels in extrapancreatic tissues like the heart, vascular smooth muscle, and skeletal muscle.
Purpose of the Study:
- To investigate the structure-function relationships of K(ATP) channels and the mechanisms of sulphonylurea selectivity.
- To understand the potential consequences of K(ATP) channel blockade in extrapancreatic tissues.
Main Methods:
- Experiments utilizing recombinant K(ATP) channels to study structure-function relationships.
- Analysis of phenotypes in mice deficient in specific K(ATP) channel subunits.
Main Results:
- Pharmacological differences in K(ATP) channels from beta cells versus other tissues are attributed to distinct sulphonylurea receptors (SUR1 and SUR2) with varying drug binding sites.
- Sulphonylureas and glinides were classified into two groups based on their selectivity for SUR1 or SUR2 channels.
Conclusions:
- Drug selectivity for pancreatic (SUR1) versus extrapancreatic (SUR2) sulphonylurea receptors is crucial for assessing potential side effects of K(ATP) channel inhibitors.
- Extrapancreatic K(ATP) channel inhibition effects may be subtle or rare, requiring further investigation before determining the suitability of non-selective agents for Type 2 diabetes therapy.