GLP-1, oxyntomodulin, glucagon, and exendin-4 did not cause acute pancreatic damage in rats, and oxyntomodulin actually inhibited amylase release, suggesting it may be safer regarding pancreatitis risk.
No pancreatic harmGLP-1, oxyntomodulin, glucagon, and exendin-4 caused no acute increase in amylase, cell proliferation, or enzyme secretion in rat pancreas models
What the researchers found
None of the four proglucagon-derived peptides caused acute harm to the exocrine pancreas:
- Plasma amylase did not increase after infusion of GLP-1, oxyntomodulin, glucagon, or exendin-4 (compared to vehicle and cholecystokinin controls)
- None of the peptides caused significant cell proliferation in pancreatic acinar or ductal cells
- None increased amylase secretion from isolated pancreatic cells
- Oxyntomodulin specifically inhibited plasma amylase when co-administered with cholecystokinin, suggesting an active protective mechanism
This positions oxyntomodulin as potentially the safest proglucagon-derived peptide for obesity treatment regarding pancreatic risk.
Why it matters
Pancreatitis has been a persistent safety concern for GLP-1 receptor agonists, with some clinical reports suggesting an increased risk. This study provides reassuring preclinical evidence that these peptides don't acutely damage the pancreas. The finding that oxyntomodulin — a dual GLP-1/glucagon receptor agonist being developed for obesity — may actually protect against pancreatic stress is particularly encouraging for the development of dual-agonist therapies.
How the study worked
GLP-1, oxyntomodulin, glucagon, and exendin-4 were infused intravenously into anesthetized Wistar rats, and plasma amylase concentrations were measured as a marker of exocrine pancreatic stress. In vitro experiments tested each peptide's effect on amylase release and cell proliferation in rat pancreatic acinar cells (AR42J cell line) and primary isolated ductal cells.
What this study cannot tell us
This study only assessed acute effects — long-term or chronic exposure effects could differ significantly. The study was conducted in rats, and rodent pancreatic physiology does not perfectly replicate human pancreatic responses. Only short-term amylase changes and cell proliferation were measured; other markers of pancreatic inflammation or injury were not assessed. The in vitro cell line (AR42J) may not fully represent normal pancreatic acinar cell behavior.
How to read the evidence
This is a preclinical animal study with both in vivo (rat infusion) and in vitro (cell culture) components. While it provides useful safety data, acute studies in rats have limited direct applicability to human chronic therapy. The findings are reassuring but cannot definitively address long-term pancreatitis risk in humans.
When this study was published
Published in 2016, this study addressed safety concerns that were prominent during the early expansion of GLP-1 drug prescribing. Since then, large-scale human safety data has further supported the conclusion that GLP-1 drugs do not significantly increase pancreatitis risk, consistent with this study's findings.
The bigger picture
The pancreatitis safety question has loomed over GLP-1 drug development for years. While regulatory agencies have concluded that the overall evidence does not support a causal link between GLP-1 drugs and pancreatitis, individual safety studies like this contribute to the evidence base. As newer dual and triple agonists (targeting both GLP-1 and glucagon receptors) enter development, understanding the pancreatic safety of each component is essential.
Questions still open
- Does oxyntomodulin's amylase-inhibiting effect translate to reduced pancreatitis risk in humans taking dual-agonist obesity drugs?
- Would chronic administration of these peptides over weeks or months produce different pancreatic effects than acute exposure?
- Are there specific patient populations (e.g., those with prior pancreatitis) where even this acute reassurance may not apply?
Common questions
Do GLP-1 drugs cause pancreatitis?
What is oxyntomodulin and how is it different from GLP-1?
Read the original research
Proglucagon-Derived Peptides Do Not Significantly Affect Acute Exocrine Pancreas in Rats.
Pancreas, 45(7), 967-73
Citation
Akalestou, Elina; Christakis, Ioannis; Solomou, Antonia M; Minnion, James S; Rutter, Guy A; Bloom, Stephen R. (2016). Proglucagon-Derived Peptides Do Not Significantly Affect Acute Exocrine Pancreas in Rats.. Pancreas, 45(7), 967-73. https://doi.org/10.1097/MPA.0000000000000585