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Warner SO, Dai Y, Sheanon N, Yao MV, Cason RL, Arbabi S, Patel SB, Lindquist D, Winnick JJ. Short-term fasting lowers glucagon levels under euglycemic and hypoglycemic conditions in healthy humans. JCI Insight 2023; 8:e169789. [PMID: 37166980 PMCID: PMC10371233 DOI: 10.1172/jci.insight.169789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 05/09/2023] [Indexed: 05/12/2023] Open
Abstract
Fasting is associated with increased susceptibility to hypoglycemia in people with type 1 diabetes, thereby making it a significant health risk. To date, the relationship between fasting and insulin-induced hypoglycemia has not been well characterized, so our objective was to determine whether insulin-independent factors, such as counterregulatory hormone responses, are adversely impacted by fasting in healthy control individuals. Counterregulatory responses to insulin-induced hypoglycemia were measured in 12 healthy people during 2 metabolic studies. During one study, participants ate breakfast and lunch, after which they underwent a 2-hour bout of insulin-induced hypoglycemia (FED). During the other study, participants remained fasted prior to hypoglycemia (FAST). As expected, hepatic glycogen concentrations were lower in FAST, and associated with diminished peak glucagon levels and reduced endogenous glucose production (EGP) during hypoglycemia. Accompanying lower EGP in FAST was a reduction in peripheral glucose utilization, and a resultant reduction in the amount of exogenous glucose required to maintain glycemia. These data suggest that whereas a fasting-induced lowering of glucose utilization could potentially delay the onset of insulin-induced hypoglycemia, subsequent reductions in glucagon levels and EGP are likely to encumber recovery from it. As a result of this diminished metabolic flexibility in response to fasting, susceptibility to hypoglycemia could be enhanced in patients with type 1 diabetes under similar conditions.
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Affiliation(s)
- Shana O. Warner
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Yufei Dai
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Nicole Sheanon
- Department of Pediatrics, Division of Pediatric Endocrinology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Michael V. Yao
- Department of Pediatrics, Division of Endocrinology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Rebecca L. Cason
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Shahriar Arbabi
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Shailendra B. Patel
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Diana Lindquist
- Imaging Research Center, Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Jason J. Winnick
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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Goutchtat R, Quenon A, Clarisse M, Delalleau N, Coddeville A, Gobert M, Gmyr V, Kerr-Conte J, Pattou F, Hubert T. Effects of subtotal pancreatectomy and long-term glucose and lipid overload on insulin secretion and glucose homeostasis in minipigs. Endocrinol Diabetes Metab 2023:e425. [PMID: 37144278 DOI: 10.1002/edm2.425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/30/2023] [Accepted: 04/10/2023] [Indexed: 05/06/2023] Open
Abstract
INTRODUCTION Nowadays, there are no strong diabetic pig models, yet they are required for various types of diabetes research. Using cutting-edge techniques, we attempted to develop a type 2 diabetic minipig model in this study by combining a partial pancreatectomy (Px) with an energetic overload administered either orally or parenterally. METHODS Different groups of minipigs, including Göttingen-like (GL, n = 17) and Ossabaw (O, n = 4), were developed. Prior to and following each intervention, metabolic assessments were conducted. First, the metabolic responses of the Göttingen-like (n = 3) and Ossabaw (n = 4) strains to a 2-month High-Fat, High-Sucrose diet (HFHSD) were compared. Then, other groups of GL minipigs were established: with a single Px (n = 10), a Px combined with a 2-month HFHSD (n = 6), and long-term intraportal glucose and lipid infusions that were either preceded by a Px (n = 4) or not (n = 4). RESULTS After the 2-month HFHSD, there was no discernible change between the GL and O minipigs. The pancreatectomized group in GL minipigs showed a significantly lower Acute Insulin Response (AIR) (18.3 ± 10.0 IU/mL after Px vs. 34.9 ± 13.7 IU/mL before, p < .0005). In both long-term intraportal infusion groups, an increase in the Insulinogenic (IGI) and Hepatic Insulin Resistance Indexes (HIRI) was found with a decrease in the AIR, especially in the pancreatectomized group (IGI: 4.2 ± 1.9 after vs. 1.5 ± 0.8 before, p < .05; HIRI (×10-5 ): 12.6 ± 7.9 after vs. 3.8 ± 4.3 before, p < .05; AIR: 24.4 ± 13.7 µIU/mL after vs. 43.9 ± 14.5 µIU/mL before, p < .005). Regardless of the group, there was no fasting hyperglycemia. CONCLUSIONS In this study, we used pancreatectomy followed by long-term intraportal glucose and lipid infusions to develop an original minipig model with metabolic syndrome and early signs of glucose intolerance. We reaffirm the pig's usefulness as a preclinical model for the metabolic syndrome but without the fasting hyperglycemia that characterizes diabetes mellitus.
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Affiliation(s)
- Rébecca Goutchtat
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, UFR3S, U1190 - Egid, Lille, France
| | - Audrey Quenon
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, UFR3S, U1190 - Egid, Lille, France
- Univ. Lille, CHU Lille, UFR3S, Département Hospitalo-Universitaire de Recherche et d'Enseignement (Dhure), Lille, France
| | | | - Nathalie Delalleau
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, UFR3S, U1190 - Egid, Lille, France
| | - Anaïs Coddeville
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, UFR3S, U1190 - Egid, Lille, France
| | - Mathilde Gobert
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, UFR3S, U1190 - Egid, Lille, France
| | - Valéry Gmyr
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, UFR3S, U1190 - Egid, Lille, France
| | - Julie Kerr-Conte
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, UFR3S, U1190 - Egid, Lille, France
| | - François Pattou
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, UFR3S, U1190 - Egid, Lille, France
| | - Thomas Hubert
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, UFR3S, U1190 - Egid, Lille, France
- Univ. Lille, CHU Lille, UFR3S, Département Hospitalo-Universitaire de Recherche et d'Enseignement (Dhure), Lille, France
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3
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Daniell H, Singh R, Mangu V, Nair SK, Wakade G, Balashova N. Affordable oral proinsulin bioencapsulated in plant cells regulates blood sugar levels similar to natural insulin. Biomaterials 2023; 298:122142. [PMID: 37148757 DOI: 10.1016/j.biomaterials.2023.122142] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 04/30/2023] [Accepted: 05/01/2023] [Indexed: 05/08/2023]
Abstract
Diabetes Mellitus is a silent epidemic affecting >500 million, which claimed 6.7 million lives in 2021, a projected increase of >670% in <20 years old in the next two decades but insulin is unaffordable for the large majority of the globe. Therefore, we engineered proinsulin in plant cells to facilitate oral delivery. Stability of the proinsulin gene and expression in subsequent generations, after removal of the antibiotic-resistance gene, was confirmed using PCR, Southern and western blots. Proinsulin expression was high (up to 12 mg/g DW or 47.5% of total leaf protein), stable up to one year after storage of freeze-dried plant cells at ambient temperature and met FDA regulatory requirements of uniformity, moisture content and bioburden. GM1 receptor binding, required for uptake via gut epithelial cells was confirmed by pentameric assembly of CTB-Proinsulin. IP insulin injections (without C peptide) in STZ mice rapidly decreased blood glucose level leading to transient hypoglycemia, followed by hepatic glucose compensation. On the other hand, other than the 15-min lag period of oral proinsulin (transit time required to reach the gut), the kinetics of blood sugar regulation of oral CTB-Proinsulin in STZ mice was very similar to naturally secreted insulin in healthy mice (both contain C-peptide), without rapid decrease or hypoglycemia. Elimination of expensive fermentation, purification and cold storage/transportation should reduce cost and increase other health benefits of plant fibers. The recent approval of plant cell delivery of therapeutic proteins by FDA and approval of CTB-ACE2 for phase I/II human clinical studies augur well for advancing oral proinsulin to the clinic.
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Affiliation(s)
- Henry Daniell
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Rahul Singh
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Venkata Mangu
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Smruti K Nair
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Geetanjali Wakade
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nataliya Balashova
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Chen L, Zhang X, Song X, Han D, Han K, Xu W, Luo R, Cao Y, Shi Y, Liu C, Xu C, Li Z, Li Y, Li X. Peripheral Gonadotropin-Inhibitory Hormone (GnIH) Acting as a Novel Modulator Involved in Hyperphagia-Induced Obesity and Associated Disorders of Metabolism in an In Vivo Female Piglet Model. Int J Mol Sci 2022; 23:ijms232213956. [PMID: 36430435 PMCID: PMC9692342 DOI: 10.3390/ijms232213956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Apart from the well-established role of the gonadotropin-inhibitory hormone (GnIH) in the regulation of the reproductive functions, much less is known about the peripheral role of the GnIH and its receptor in the metabolic processes. On account of pig being an excellent model for studies of food intake and obesity in humans, we investigated the peripheral effects of the GnIH on food intake and energy homeostasis and revealed the underlying mechanism(s) in female piglets in vivo. Compared to the vehicle-treated group, intraperitoneally injected GnIH significantly increased the food intake and altered the meal microstructure both in the fasting and ad libitum female piglet. GnIH-triggered hyperphagia induced female piglet obesity and altered islet hormone secretion in the pancreas, accompanied with dyslipidemia and hyperglycemia. Interestingly, GnIH decreased the glucose transport capacity and glycogen synthesis, whereas it increased the gluconeogenesis in the liver, while it also induced an insulin resistance in white adipose tissue (WAT) via inhibiting the activity of AKT-GSK3-β signaling. In terms of the lipid metabolism, GnIH reduced the oxidation of fatty acids, whereas the elevated fat synthesis ability in the liver and WAT was developed though the inhibited AMPK phosphorylation. Our findings demonstrate that peripheral GnIH could trigger hyperphagia-induced obesity and an associated glycolipid metabolism disorder in female piglets, suggesting that GnIH may act as a potential therapeutic agent for metabolic syndrome, obesity and diabetes.
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Affiliation(s)
- Lei Chen
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Xin Zhang
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Xingxing Song
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Dongyang Han
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Kaiou Han
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Wenhao Xu
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Rongrong Luo
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Yajie Cao
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Yan Shi
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Chengcheng Liu
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Changlin Xu
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Zixin Li
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Yinan Li
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
| | - Xun Li
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China
- Guangxi Key Laboratory of Animal Reproduction, Breeding and Disease Control, Nanning 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning 530004, China
- Correspondence: ; Tel.: +86-(07)-7132-35635
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Yu S, Li C, Ji G, Zhang L. The Contribution of Dietary Fructose to Non-alcoholic Fatty Liver Disease. Front Pharmacol 2021; 12:783393. [PMID: 34867414 PMCID: PMC8637741 DOI: 10.3389/fphar.2021.783393] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 11/02/2021] [Indexed: 12/26/2022] Open
Abstract
Fructose, especially industrial fructose (sucrose and high fructose corn syrup) is commonly used in all kinds of beverages and processed foods. Liver is the primary organ for fructose metabolism, recent studies suggest that excessive fructose intake is a driving force in non-alcoholic fatty liver disease (NAFLD). Dietary fructose metabolism begins at the intestine, along with its metabolites, may influence gut barrier and microbiota community, and contribute to increased nutrient absorption and lipogenic substrates overflow to the liver. Overwhelming fructose and the gut microbiota-derived fructose metabolites (e.g., acetate, butyric acid, butyrate and propionate) trigger the de novo lipogenesis in the liver, and result in lipid accumulation and hepatic steatosis. Fructose also reprograms the metabolic phenotype of liver cells (hepatocytes, macrophages, NK cells, etc.), and induces the occurrence of inflammation in the liver. Besides, there is endogenous fructose production that expands the fructose pool. Considering the close association of fructose metabolism and NAFLD, the drug development that focuses on blocking the absorption and metabolism of fructose might be promising strategies for NAFLD. Here we provide a systematic discussion of the underlying mechanisms of dietary fructose in contributing to the development and progression of NAFLD, and suggest the possible targets to prevent the pathogenetic process.
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Affiliation(s)
- Siyu Yu
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Chunlin Li
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Guang Ji
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Li Zhang
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Leptin treatment prevents impaired hypoglycemic counterregulation induced by exposure to severe caloric restriction or exposure to recurrent hypoglycemia. Auton Neurosci 2021; 235:102853. [PMID: 34358845 DOI: 10.1016/j.autneu.2021.102853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 06/06/2021] [Accepted: 07/07/2021] [Indexed: 02/07/2023]
Abstract
Hypoglycemia-associated autonomic failure (HAAF) is a maladaptive failure in glucose counterregulation in persons with diabetes (PWD) that is caused by recurrent exposure to hypoglycemia. The adipokine leptin is known to regulate glucose homeostasis, and leptin levels fall following exposure to recurrent hypoglycemia. Yet, little is known regarding how reduced leptin levels influence glucose counterregulation, or if low leptin levels are involved in the development of HAAF. The purpose of this study was to determine the effect of hypoleptinemia on the neuroendocrine responses to hypoglycemia. We utilized two separate experimental paradigms known to induce a hypoleptinemic state: 60% caloric restriction (CR) in mice and three days of recurrent hypoglycemia (3dRH) in rats. A sub-set of animals were also treated with leptin (0.5-1.0 μg/g) during the CR or 3dRH periods. Neuroendocrine responses to hypoglycemia were assessed 60 min following an IP insulin injection on the terminal day of the paradigms. CR mice displayed defects in hypoglycemic counterregulation, indicated by significantly lower glucagon levels relative to controls, 13.5 pmol/L (SD 10.7) versus 64.7 pmol/L (SD 45) (p = 0.002). 3dRH rats displayed reduced epinephrine levels relative to controls, 1900 pg/mL (SD 1052) versus 3670 pg/mL (SD 780) (p = 0.030). Remarkably, leptin treatment during either paradigm completely reversed this effect by normalizing glucagon levels in CR mice, 78.0 pmol/L (SD 47.3) (p = 0.764), and epinephrine levels in 3dRH rats, 2910 pg/mL (SD 1680) (p = 0.522). These findings suggest that hypoleptinemia may be a key signaling event driving the development of HAAF and that leptin treatment may prevent the development of HAAF in PWD.
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Moore MC, Warner SO, Dai Y, Sheanon N, Smith M, Farmer B, Cason RL, Cherrington AD, Winnick JJ. C-peptide enhances glucagon secretion in response to hyperinsulinemia under euglycemic and hypoglycemic conditions. JCI Insight 2021; 6:148997. [PMID: 34003799 PMCID: PMC8262495 DOI: 10.1172/jci.insight.148997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/12/2021] [Indexed: 12/17/2022] Open
Abstract
Several studies have associated the presence of residual insulin secretion capability (also referred to as being C-peptide positive) with lower risk of insulin-induced hypoglycemia in patients with type 1 diabetes (T1D), although the reason is unclear. We tested the hypothesis that C-peptide infusion would enhance glucagon secretion in response to hyperinsulinemia during euglycemic and hypoglycemic conditions in dogs (5 male/4 female). After a 2-hour basal period, an intravenous (IV) infusion of insulin was started, and dextrose was infused to maintain euglycemia for 2 hours. At the same time, an IV infusion of either saline (SAL) or C-peptide (CPEP) was started. After this euglycemic period, the insulin and SAL/CPEP infusions were continued for another 2 hours, but the glucose was allowed to fall to approximately 50 mg/dL. In response to euglycemic-hyperinsulinemia, glucagon secretion decreased in SAL but remained unchanged from the basal period in CPEP condition. During hypoglycemia, glucagon secretion in CPEP was 2 times higher than SAL, and this increased net hepatic glucose output and reduced the amount of exogenous glucose required to maintain glycemia. These data suggest that the presence of C-peptide during IV insulin infusion can preserve glucagon secretion during euglycemia and enhance it during hypoglycemia, which could explain why T1D patients with residual insulin secretion are less susceptible to hypoglycemia.
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Affiliation(s)
- Mary Courtney Moore
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Shana O. Warner
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Yufei Dai
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Nicole Sheanon
- Department of Endocrinology, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Marta Smith
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Ben Farmer
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Rebecca L. Cason
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Alan D. Cherrington
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Jason J. Winnick
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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