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D’Souza NC, Aiken JA, Hoffman EG, Atherley SC, Champsi S, Aleali N, Shakeri D, El-Zahed M, Akbarian N, Nejad-Mansouri M, Bavani PZ, Liggins RL, Chan O, Riddell MC. Evaluating the effectiveness of a novel somatostatin receptor 2 antagonist, ZT-01, for hypoglycemia prevention in a rodent model of type 2 diabetes. Front Pharmacol 2024; 15:1302015. [PMID: 38510652 PMCID: PMC10951717 DOI: 10.3389/fphar.2024.1302015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 01/29/2024] [Indexed: 03/22/2024] Open
Abstract
Background: Elevated levels of somatostatin blunt glucagon counterregulation during hypoglycemia in type 1 diabetes (T1D) and this can be improved using somatostatin receptor 2 (SSTR2) antagonists. Hypoglycemia also occurs in late-stage type 2 diabetes (T2D), particularly when insulin therapy is initiated, but the utility of SSTR2 antagonists in ameliorating hypoglycemia in this disease state is unknown. We examined the efficacy of a single-dose of SSTR2 antagonists in a rodent model of T2D. Methods: High-fat fed (HFF), low dose streptozotocin (STZ, 35 mg/kg)-induced T2D and HFF only, nondiabetic (controls-no STZ) rats were treated with the SSTR2 antagonists ZT-01/PRL-2903 or vehicle (n = 9-11/group) 60 min before an insulin tolerance test (ITT; 2-12 U/kg insulin aspart) or an oral glucose tolerance test (OGTT; 2 g/kg glucose via oral gavage) on separate days. Results: This rodent model of T2D is characterized by higher baseline glucose and HbA1c levels relative to HFF controls. T2D rats also had lower c-peptide levels at baseline and a blunted glucagon counterregulatory response to hypoglycemia when subjected to the ITT. SSTR2 antagonists increased the glucagon response and reduced incidence of hypoglycemia, which was more pronounced with ZT-01 than PRL-2903. ZT-01 treatment in the T2D rats increased glucagon levels above the control response within 60 min of dosing, and values remained elevated during the ITT (glucagon Cmax: 156 ± 50 vs. 77 ± 46 pg/mL, p < 0.01). Hypoglycemia incidence was attenuated with ZT-01 vs. controls (63% vs. 100%) and average time to hypoglycemia onset was also delayed (103.1 ± 24.6 vs. 66.1 ± 23.6 min, p < 0.05). ZT-01 administration at the OGTT onset increased the glucagon response without exacerbating hyperglycemia (2877 ± 806 vs. 2982 ± 781), potentially due to the corresponding increase in c-peptide levels (6251 ± 5463 vs. 14008 ± 5495, p = 0.013). Conclusion: Treatment with SSTR2 antagonists increases glucagon responses in a rat model of T2D and results in less hypoglycemia exposure. Future studies are required to determine the best dosing periods for chronic SSTR2 antagonism treatment in T2D.
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Affiliation(s)
| | - Julian A. Aiken
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Emily G. Hoffman
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Sara C. Atherley
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Sabrina Champsi
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Nadia Aleali
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Dorsa Shakeri
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Maya El-Zahed
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Nicky Akbarian
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | | | - Parinaz Z. Bavani
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | | | - Owen Chan
- Department of Internal Medicine, Division of Endocrinology, University of Utah, Salt LakeCity, UT, United States
| | - Michael C. Riddell
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
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