The selective β2-adrenergic agonist clenbuterol was ineffective as a stimulus for insulin secretion when isolated rat pancreatic islets were incubated with glucose at concentrations between 4 and 20 mM. Inclusion of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine led to potentiation of glucose-induced insulin secretion, but did not facilitate stimulation by clenbuterol. Furthermore, maintenance of isolated rat islets for up to 3 days in tissue culture also failed to result in the appearance of a secretory response to β-agonists. By contrast, clenbuterol induced a dose-dependent increase in insulin release from isolated human islets incubated with 20 mm glucose. Clenbuterol did not increase the basal rate of insulin secretion (4 mm glucose) in human islets. Under perifusion conditions, the secretory response of human islets to clenbuterol was rapid, of similar magnitude to that seen under static incubation conditions and could be sustained for at least 30 min. The increase in insulin secretion induced by clenbuterol was inhibited by propranolol, indicating that the response was mediated by activation of β-receptors. In support of this, a similar enhancement of glucose-induced insulin secretion was elicited by a different β2-agonist, salbutamol, in human islets. The results indicate that the B cells of isolated rat islets are unresponsive to β-agonists, whereas those of human islets are equipped with functional β-receptors which can directly influence the rate of insulin secretion.
Journal of Molecular Endocrinology is committed to supporting researchers in demonstrating the impact of their articles published in the journal.
The two types of article metrics we measure are (i) more traditional full-text views and pdf downloads, and (ii) Altmetric data, which shows the wider impact of articles in a range of non-traditional sources, such as social media.
More information is on the Reasons to publish page.
| Sept 2018 onwards | Past Year | Past 30 Days | |
|---|---|---|---|
| Full Text Views | 4 | 1 | 0 |
| PDF Downloads | 5 | 1 | 0 |
Online ISSN: 1479-6813
Print ISSN: 0952-5041
Strengthening biomedical communities
to advance science and health
CONTACT US
Bioscientifica Ltd | Starling House | 1600 Bristol Parkway North | Bristol BS34 8YU | UK
Bioscientifica Ltd | Registered in England no 3190519
