Glucagon ELISA

Glucagon is a 29-amino acid peptide that is produced from the cleavage of proglucagon (160 amino acids) by proprotein convertase 2 in pancreatic alpha cells. In intestinal L‐cells, proglucagon is cleaved into glicentin, a 69 amino acid peptide. Glicentin can further be processed into a 37 amino acid peptide oxyntomodulin. These peptides are released simultaneously upon stimulation^1-5. Glucagon is involved in carbohydrate, fat, and protein metabolism and is the main catabolic hormone of the body. Glucagon raises the concentration of glucose and fatty acids in the bloodstream and plays an important role in maintaining glucose homeostasis by promoting gluconeogenesis and glycogenolysis. Glucagon has traditionally been considered an antagonist to insulin, with insulin reducing blood glucose levels and glucagon increasing them. As the level of blood glucose decreases, the pancreas releases more glucagon. As blood glucose increases, the pancreas releases less glucagon. Once blood glucose levels have normalized, glucagon secretion ceases^{1, 2, 6, 7}. Glucagon also decreases fatty acid synthesis in adipose tissue and the liver and promotes lipolysis in these tissues, which causes them to release fatty acids into circulation where they can be catabolized to generate energy in tissues such as skeletal muscle when required⁸. Glucagon also regulates the rate of glucose production through lipolysis.

Glucagon induces lipolysis in humans under conditions of insulin suppression⁹. Glucagon is secreted from the alpha cells of the pancreatic islets of Langerhans. Recent research has demonstrated that glucagon production may also occur outside the pancreas, with the gut being the most likely site of extra pancreatic glucagon synthesis¹⁰. IVD Glucagon in diabetics has been found elevated absolutely or relatively to insulin, and it has been proposed that glucagon contributes to the development of hyper- and hypoglycemia^11-15. Researchers have found that patients with diabetes are more likely to develop pancreatitis^16-20.

The IBL-America Glucagon ELISA may be used in combination with other clinical and laboratory data as an aid in diagnosing carbohydrate metabolism disorders related to glucagon levels, including hyper- and hypoglycemia, and pancreatitis.

The Glucagon ELISA is a two-step quantitative capture or ‘sandwich’ type immunoassay. The assay utilizes two highly specific monoclonal antibodies. One glucagon-specific monoclonal antibody is immobilized onto the microplate well to capture the glucagon present in the EDTA plasma sample. The second monoclonal antibody is specific for a different epitope of glucagon and is conjugated to horse radish peroxidase to enable the formation of the sandwich. The absorbance is measured on a microplate reader at 450 nm. This ELISA can be performed in under 2 hours utilizing room temperature incubations without shaking the plate. The Glucagon ELISA is 510(k) Exempt - For in vitro diagnostic use only.

The kit contains reagents required to perform the assay, including calibrator stock material, assay controls, strip holder with 12 strips of eight wells, conjugate and TMB substrate.

Pipettes, plate washer and plate reader (450 nm) are not included. Please read the Glucagon ELISA package insert for full details on the assay. 

This manual assay may be adapted to open automated analyzers. The user is responsible for validating the performance of this kit, as a manual assay or with any automated analyzer system.

Thirty-six potential interferents were tested in the assay. Twenty-one potential cross-reactants were tested. Also, no cross-reactivity for oxyntomodulin, glicentin, etc. was found.  Please see the package insert for full performance characteristics of the assay.

Laboratory professionals may order this product from IBL-America (Glucagon ELISA, IB59142 (IVD) | Human Glucagon Competitive Enzyme-linked Immune-sorbent Assay Kit IBL America).  The catalog number is IB59142. Please contact IBL-America with questions or for more information.

References

¹Kobayashi M et al. A newly developed glucagon sandwich ELISA is useful for more accurate glucagon evaluation than the currently used sandwich ELISA in subjects with elevated plasma proglucagon-derived peptide levels. J Diabetes Investig. 2023; May;14(5):648-658;doi: 10.1111/jdi.13986. Epub 2023 Feb 2. PMID: 36729958; PMCID: PMC10119918.

²Rix I, Nexøe-Larsen C, Bergmann NC, et al. Glucagon Physiology. [Updated 2019 Jul 16]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279127/

³Taborsky GJ Jr. The physiology of glucagon. J Diabetes Sci Technol. 2010 Nov 1;4(6):1338-1344. doi: 10.1177/193229681000400607. PMID: 21129328; PMCID: PMC3005043.

⁴Sandoval DA, D'Alessio DA. Physiology of proglucagon peptides: role of glucagon and GLP-1 in health and disease. Physiol Rev. 2015 Apr;95(2):513-548. doi: 10.1152/ physrev.00013.2014. PMID: 25834231.

⁵Holst JJ. Glucagon and glucagon-like peptides 1 and 2. Results Probl Cell Differ. 2010; 50:121-135. doi: 10.1007/400_2009_35. PMID: 19960378.

⁶Bagger JI, Knop FK, Holst JJ, et al. Glucagon antagonism as a potential therapeutic target in type 2 diabetes. Diabetes Obes Metab. 2011 Nov;13(11):965-971. doi: 10.1111/j.1463-1326.2011.01427. x. PMID: 21615669.

⁷Zhang X, Yang S, Chen J, et al. Unraveling the Regulation of Hepatic Gluconeogenesis. Front Endocrinol (Lausanne). 2019 Jan 24; 9:802. doi: 10.3389/fendo.2018.00802. PMID: 30733709; PMCID: PMC6353800.

⁸Habegger KM, Heppner KM, Geary N, et al. The metabolic actions of glucagon revisited. Nat Rev Endocrinol. 2010 Dec;6(12):689-697. doi: 10.1038/nrendo.2010.187. Epub 2010 Oct 19. PMID: 20957001; PMCID: PMC3563428.

⁹Hayashi Y. Glucagon regulates lipolysis and fatty acid oxidation through inositol triphosphate receptor 1 in the liver. J Diabetes Investig. 2021 Jan;12(1):32-34. doi: 10.1111/jdi.13315. Epub 2020 Jul 26. PMID: 32506830; PMCID: PMC7779274.

¹⁰Holst JJ, Holland W, Gromada J, et al. Insulin and Glucagon: Partners for Life. Endocrinology. 2017 Apr 1;158(4):696-701. doi: 10.1210/en.2016 1748. PMID: 28323959; PMCID: PMC6061217.

¹¹Fanelli CG, Porcellati F, Rossetti P, et al. Glucagon: the effects of its excess and deficiency on insulin action. Nutr Metab Cardiovasc Dis. 2006 Mar;16 Suppl 1: S28-34. doi: 10.1016/j.numecd.2005.10.018. Epub 2006 Feb 9. PMID: 16530126.

¹²Cryer PE. Minireview: Glucagon in the pathogenesis of hypoglycemia and hyperglycemia in diabetes. Endocrinology. 2012 Mar;153(3):1039-1048. doi: 10.1210/en.2011-1499. Epub 2011 Dec 13. PMID: 22166985; PMCID: PMC3281526.

¹³Lena Mumme, Thomas G.K. Breuer, Stephan Rohrer, et al. Defects in α Cell Function in Patients with Diabetes Due to Chronic Pancreatitis Compared with Patients with Type 2 Diabetes and Healthy Individuals. Diabetes Care 1 October 2017; 40 (10): 1314–1322. https://doi.org/10.2337/dc17-0792 PubMed: 28751547

¹⁴Aris Siafarikas, Robert J. Johnston, Max K. Bulsara, et al. Early Loss of the Glucagon Response to Hypoglycemia in Adolescents with Type 1 Diabetes. Diabetes Care 1 August 2012; 35 (8): 1757–1762. https://doi.org/10.2337/dc11-2010 PubMed: 22699295

¹⁵Bogachus LD, Bellin MD, Vella A, et al. Deficient Glucagon Response to Hypoglycemia During a Mixed Meal in Total Pancreatectomy/Islet Autotransplantation Recipients. J Clin Endocrinol Metab. 2018 Apr 1;103(4):1522-1529. doi: 10.1210/jc.2017-02182. PMID: 29351616; PMCID: PMC6276676.

¹⁶Uc A, Andersen DK, Bellin MD, et al. Chronic Pancreatitis in the 21st Century - Research Challenges and Opportunities: Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop. Pancreas. 2016 Nov;45(10):1365-1375. doi: 10.1097/MPA.0000000000000713. PMID: 27748719; PMCID: PMC5117429.

¹⁷Richardson A, Park WG. Acute pancreatitis and diabetes mellitus: a review. Korean J Intern Med. 2021;36(1):15-24. doi:10.3904/kjim.2020.505

¹⁸Urushihara H, Taketsuna M, Liu Y, et al. Increased risk of acute pancreatitis in patients with type 2 diabetes: an observational study using a Japanese hospital database. PLOS ONE. 2012;7(12): e53224. doi: 10.1371/journal.pone.0053224

¹⁹Makuc J. Management of pancreatogenic diabetes: challenges and solutions. Diabetes Metab Syndr Obes. 2016; 9:311-315. doi:10.2147/DMSO.S99701

²⁰Lv Y, Lu X, Liu G, et al. Differential diagnosis of post pancreatitis diabetes mellitus based on pancreatic and gut hormone characteristics. J Clin Endocrinol Metab. 2024 Feb 12: dgae080. doi: 10.1210/clinem/dgae080. Epub ahead of print. Erratum in: J Clin Endocrinol Metab. 2024 Apr 17: dgae232. doi: 10.1210/clinem/dgae232. PMID: 38344778.