Scientists pioneered experiments into the regulation of blood glucose. They isolated an active extract from pancreatic islet tissues, which they named "glucagonin".
To test its effects, they administered injections of glucagonin to fasted animal subjects and monitored their blood glucose levels over time.
The graph below is a summary of the results.
Which of the following statements is/are correct interpretations of these experimental findings?
- Glucagonin is synthesized and secreted by the β \beta\,β cells in the islets of Langerhans.
- Glucagonin increases blood glucose concentration.
- The effects of glucagonin are short-lived.
1, 2 and 3
Only 1 and 2
Only 2 and 3
Only 1