Stimulation of insulin release by thiols

Area of Science:

• Biochemistry
• Endocrinology
• Cell Biology

Background:

• Insulin release is crucial for glucose homeostasis.
• The role of thiol compounds in modulating insulin secretion requires further investigation.

Purpose of the Study:

• To investigate the effects of thiol compounds on insulin release from pancreatic islets.
• To explore the mechanism by which thiols influence glucose-induced insulin secretion.

Main Methods:

• Microdissected pancreatic islets from ob/ob mice were used.
• Insulin release was measured in response to glucose and thiol compounds.
• Reactivity of thiols and insulin degradation were assessed.
• Microperifusion experiments were conducted.

Main Results:

• 1-thio-D-glucose and reduced glutathione (at 0.1 mM) potentiated 10 mM D-glucose-induced insulin release.
• Dextran-linked L-cysteine also potentiated glucose-stimulated insulin secretion.
• No thiol stimulated insulin release in the absence of glucose.
• 1-thio-D-glucose showed rapid onset but declining insulin release compared to glucose alone.

Conclusions:

• Thiol compounds can potentiate glucose-stimulated insulin release.
• The mechanism may involve the splitting of beta-cell membrane disulfides.
• Thiols do not induce insulin release independently of glucose.