Related Experiment Videos
Alpha 2-adrenoceptors modulating insulin release from isolated pancreatic islets
Naunyn-Schmiedeberg'S Archives of Pharmacology
|August 1, 1980
Summary
This study shows that alpha 2-adrenoceptors on pancreatic islets block insulin release. Yohimbine and phentolamine effectively blocked this inhibition, indicating their role in regulating glucose-stimulated insulin secretion.
Area of Science:
- Endocrinology
- Pharmacology
- Molecular Biology
Background:
- Adrenaline is known to inhibit insulin release.
- Alpha-adrenoceptors are involved in regulating various physiological processes, including insulin secretion.
Purpose of the Study:
- To investigate the role of specific alpha-adrenoceptor subtypes in mediating the inhibitory effects of adrenaline on glucose-stimulated insulin release from rat pancreatic islets.
- To compare the potency of various alpha-adrenoceptor blocking agents in antagonizing adrenaline's inhibitory action.
Main Methods:
- Isolated rat pancreatic islets were used.
- The effects of different alpha-adrenoceptor antagonists (yohimbine, prazosin, phentolamine, dihydroergotamine, WB-4101, phenoxybenzamine) on adrenaline-induced inhibition of insulin release were assessed.
- Dose-response relationships were analyzed to determine antagonist potency.
Main Results:
- Yohimbine was significantly more potent (approximately 100 times) than prazosin in blocking adrenaline's inhibitory effect.
- Phentolamine showed comparable antagonism to yohimbine at 10 micro M.
- Dihydroergotamine, WB-4101, and phenoxybenzamine exhibited less effective antagonism, while prazosin showed minimal antagonism.
Conclusions:
- The findings strongly suggest that post-synaptic alpha 2-adrenoceptors play a crucial role in modulating insulin release from pancreatic islets.
- Alpha 2-adrenoceptors are key regulators of glucose-stimulated insulin secretion, mediating the inhibitory effects of adrenaline.