During historical physiological investigations into the endocrine control of blood glucose, scientists isolated an active peptide extract from pancreatic islet tissue and named it insulon.
To determine its physiological action, they administered intravenous injections of insulon to healthy animal subjects and monitored their blood glucose levels over time.
The graph below represents their experimental findings:
Which of the following statements is/are correct interpretations of these experimental findings?
- Insulon is synthesized and secreted by the α \alpha\,α cells of the islets of Langerhans.
- Insulon acts to reduce the concentration of glucose in the blood.
- The blood-glucose-lowering effect of a single injection of insulon is transient.
Only 1 and 2
Only 2 and 3
1, 2 and 3
Only 2