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Puławski W, Dec R, Dzwolak W. Clues to the Design of Aggregation-Resistant Insulin from Proline Scanning of Highly Amyloidogenic Peptides Derived from the N-Terminal Segment of the A-Chain. Mol Pharm 2024; 21:2025-2033. [PMID: 38525800 PMCID: PMC10988558 DOI: 10.1021/acs.molpharmaceut.4c00077] [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: 01/21/2024] [Revised: 03/05/2024] [Accepted: 03/12/2024] [Indexed: 03/26/2024]
Abstract
Insulin aggregation poses a significant problem in pharmacology and medicine as it occurs during prolonged storage of the hormone and in vivo at insulin injection sites. We have recently shown that dominant forces driving the self-assembly of insulin fibrils are likely to arise from intermolecular interactions involving the N-terminal segment of the A-chain (ACC1-13). Here, we study how proline substitutions within the pilot GIVEQ sequence of this fragment affect its propensity to aggregate in both neutral and acidic environments. In a reasonable agreement with in silico prediction based on the Cordax algorithm, proline substitutions at positions 3, 4, and 5 turn out to be very effective in preventing aggregation according to thioflavin T-fluorescence-based kinetic assay, infrared spectroscopy, and atomic force microscopy (AFM). Since the valine and glutamate side chains within this segment are strongly involved in the interactions with the insulin receptor, we have focused on the possible implications of the Q → P substitution for insulin's stability and interactions with the receptor. To this end, comparative molecular dynamics (MD) simulations of the Q5P mutant and wild-type insulin were carried out for both free and receptor-bound (site 1) monomers. The results point to a mild destabilization of the mutant vis à vis the wild-type monomer, as well as partial preservation of key contacts in the complex between Q5P insulin and the receptor. We discuss the implications of these findings in the context of the design of aggregation-resistant insulin analogues retaining hormonal activity.
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Affiliation(s)
- Wojciech Puławski
- Bioinformatics
Laboratory, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawinski Street 5, 02-106 Warsaw, Poland
| | - Robert Dec
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
| | - Wojciech Dzwolak
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
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2
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Saelue P, Sripakdee W, Suknuntha K. Effects of Drug Concentration, Rate of Infusion, and Flush Volume on G-CSF Drug Loss When Administered Intravenously. Hosp Pharm 2019; 54:393-397. [PMID: 31762488 DOI: 10.1177/0018578718811156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Purpose: This study evaluated factors that affect granulocyte-colony stimulating factor (G-CSF) adsorption in the infusion tube by measuring the G-CSF concentration, rate of G-CSF infusion, and volume of flush solution. Methods: The concentrations of G-CSF in all samples were measured by an enzyme-linked immunosorbent assay (ELISA) using human G-CSF Quantikine® ELISA kits. The concentration of G-CSF, the rate of administration, and the volume of flush solution were studied respectively. The concentration of G-CSF and the rate of administration that had a significantly lower G-CSF percent recovery after the infusion via the infusion set were used for further investigation in the study. All samples were diluted with 5% dextrose in water (D5W) to the final concentration within the standard concentration range. All experiments were performed in triplicate. Results: The concentration of G-CSF that was administered through the infusion tube at 20 µg/mL was a significantly higher G-CSF percent recovery compared with the G-CSF concentrations of 5, 10, and 15 µg/mL. The infusion rate of 15 and 20 mL/h percent recovery of G-CSF adsorption was significantly higher than the infusion rates of 30 and 40 mL/h. The concentration of G-CSF at 15 µg/mL and an infusion rate of 30 mL/h were selected to investigate the flush volumes of D5W on G-CSF adsorption. The D5W flush volume of 40 mL dramatically decreased the G-CSF adsorption with a recovery of 103 ± 1.73%. Conclusion: The G-CSF concentration of 20 µg/mL with an infusion rate of 20 mL/h, using a 40 mL D5W flush, was appropriate for intravenous G-CSF administration.
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Affiliation(s)
- Pirun Saelue
- Faculty of Medicine, Prince of of Songkla University, Songkhla, Thailand
| | - Warunsuda Sripakdee
- Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla, Thailand
| | - Krit Suknuntha
- Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla, Thailand
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3
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Rajan R, Suzuki Y, Matsumura K. Zwitterionic Polymer Design that Inhibits Aggregation and Facilitates Insulin Refolding: Mechanistic Insights and Importance of Hydrophobicity. Macromol Biosci 2018; 18:e1800016. [DOI: 10.1002/mabi.201800016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/21/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Robin Rajan
- School of Materials Science; Japan Advanced Institute of Science and Technology; 1-1 Asahidai Nomi Ishikawa 923-1292 Japan
- School of Chemical and Biomedical Engineering; Nanyang Technological University; 62 Nanyang Drive Singapore 637459 Singapore
| | - Yu Suzuki
- Tenure-Track Program for Innovative Research; University of Fukui; 3-9-1 Bunkyo Fukui-shi Fukui 910-8507 Japan
| | - Kazuaki Matsumura
- School of Materials Science; Japan Advanced Institute of Science and Technology; 1-1 Asahidai Nomi Ishikawa 923-1292 Japan
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4
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Zimmerman R. The dawn phenomenon: variability in occurrence may cause need for change in treatment strategy. Endocr Pract 2014; 20:1352-3. [PMID: 25297670 DOI: 10.4158/ep14364.co] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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5
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Teska BM, Alarcón J, Pettis RJ, Randolph TW, Carpenter JF. Effects of phenol and meta-cresol depletion on insulin analog stability at physiological temperature. J Pharm Sci 2014; 103:2255-67. [PMID: 24909933 DOI: 10.1002/jps.24039] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 05/13/2014] [Accepted: 05/16/2014] [Indexed: 11/11/2022]
Abstract
The stability of three commercial "fast-acting" insulin analogs, insulin lispro, insulin aspart, and insulin glulisine, was studied at various concentrations of phenolic preservatives (phenol and/or meta-cresol) during 9 days of incubation at 37 °C. The analysis by both size-exclusion and reversed-phase chromatography showed degradation of lispro and aspart that was inversely dependent on the concentration of phenolic preservatives. Insulin glulisine was much more stable than the other analogs and showed minimal degradation even in the absence of phenolic preservatives. With sedimentation velocity ultracentrifugation, we determined the preservatives' effect on the insulins' self-assembly. When depleted of preservatives, insulin glulisine dissociates from higher molecular weight species into a number of intermediate molecular weight species, in between monomer and hexamer, whereas insulin aspart and insulin lispro dissociate into monomers and dimers. Decreased stability of insulin lispro and insulin aspart seems to be because of the extent of dissociation when depleted of preservative. Insulin glulisine's dissociation to intermediate molecular weight species appears to help minimize its degradation during incubation at 37 °C.
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Affiliation(s)
- Brandon M Teska
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045
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Porcellati F, Lucidi P, Bolli GB, Fanelli CG. Thirty years of research on the dawn phenomenon: lessons to optimize blood glucose control in diabetes. Diabetes Care 2013; 36:3860-2. [PMID: 24265365 PMCID: PMC3836156 DOI: 10.2337/dc13-2088] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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7
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Gregory JM, Moore DJ. Can technological solutions for diabetes replace islet cell function? Organogenesis 2011; 7:32-41. [PMID: 21289480 DOI: 10.4161/org.7.1.14028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The central objective of diabetes research and management is to restore the deficient secretion of insulin, thereby restoring a state of euglycemia and minimizing short- and long-term risks associated with poor glucose control. The development of the artificial pancreas seeks to imitate the action of the pancreatic beta cell by employing closed-loop control to respond to glycemic excursions by appropriately infusing appropriate amounts of insulin. This article examines progress towards implementing an artificial pancreas in the context of the pancreatic islet as the ideal model for controlling blood glucose. Physiologic insulin secretion will form our foundation for considering the technical design elements relevant to electromechanically imitating the beta cell. The most recent clinical trials using closed-loop control are reviewed and this modality is compared to other curative approaches including islet cell transplantation and preservation. Finally, the potential of the artificial pancreas as a method to adequately reestablish euglycemia is considered.
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Affiliation(s)
- Justin M Gregory
- Department of Pediatrics, University of Tennessee School of Medicine, Memphis, TN, USA
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8
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Sluzky V, Klibanov AM, Langer R. Mechanism of insulin aggregation and stabilization in agitated aqueous solutions. Biotechnol Bioeng 2010; 40:895-903. [PMID: 18601196 DOI: 10.1002/bit.260400805] [Citation(s) in RCA: 160] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Undesirable aggregation of aqueous insulin solutions remains a serious obstacle in the development of alternative methods of diabetes therapy. We investigated the fundamental nature of the aggregation mechanism and proposed stabilization strategies based on a mathematical model for the reaction scheme. Insulin aggregation kinetics in the presence of solid-liquid and air-liquid interfaces were monitored using UV spectroscopy and quasielastic light scattering (QELS). Experimental observations were consistent with our model of monomer denaturation at hydrophobic surfaces followed by the formation of stable intermediate species which facilitated subsequent macroaggregation. The model was used to predict qualitative trends in insulin aggregation behavior, to propose stabilization strategies, and to elucidate mechanisms of stabilization. In the absence of additives, insulin solutions aggregated completely (more than 95% of the soluble protein lost) within 24 h; with sugar-based nonionic detergents, no detectable loss occurred for more than 6 weeks.
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Affiliation(s)
- V Sluzky
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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9
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Staples M. Microchips and controlled-release drug reservoirs. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2010; 2:400-17. [DOI: 10.1002/wnan.93] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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10
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Zhang K, Quan C, Huang H, Taulier N, Wu XY. On the stability of Insulin delivered through a new glucose-responsive polymeric composite membrane. J Pharm Pharmacol 2010; 56:611-20. [PMID: 15142338 DOI: 10.1211/0022357023376] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Abstract
A new glucose-responsive polymeric composite membrane that provided pulsatile insulin release was developed in our laboratory previously. To develop a clinically useful insulin delivery system, this study was designed to investigate factors influencing insulin stability during delivery by this membrane. The effects of stirring, release duration, insulin concentration and surfactant on insulin stability were studied under both incubation and delivery conditions in a buffer solution at 37°C. The structural change of insulin was characterized by reverse-phase HPLC and circular dichroism. Hydrophobicity of various contact surfaces was determined by contact angle measurement. The results indicated that insulin concentration played an important role in the insulin stability, followed by stirring. Treating the membrane with a non-ionic surfactant prevented insulin denaturation during delivery through the membrane.
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Affiliation(s)
- Kai Zhang
- Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada, M5S 2S2
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11
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Ishikawa T, Kobayashi N, Osawa C, Sawa E, Wakamatsu K. Prevention of Stirring-Induced Microparticle Formation in Monoclonal Antibody Solutions. Biol Pharm Bull 2010; 33:1043-6. [DOI: 10.1248/bpb.33.1043] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Tomoyoshi Ishikawa
- Bio Process Research and Development Laboratories, Production Division, Kyowa Hakko Kirin Company Limited
- Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University
| | - Noritaka Kobayashi
- Bio Process Research and Development Laboratories, Production Division, Kyowa Hakko Kirin Company Limited
| | - Chie Osawa
- Bio Process Research and Development Laboratories, Production Division, Kyowa Hakko Kirin Company Limited
| | - Eiji Sawa
- Bio Process Research and Development Laboratories, Production Division, Kyowa Hakko Kirin Company Limited
| | - Kaori Wakamatsu
- Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University
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12
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Staples M, Daniel K, Cima MJ, Langer R. Application of Micro- and Nano-Electromechanical Devices to Drug Delivery. Pharm Res 2006; 23:847-63. [PMID: 16715375 DOI: 10.1007/s11095-006-9906-4] [Citation(s) in RCA: 229] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Accepted: 12/27/2005] [Indexed: 11/28/2022]
Abstract
Micro- and nano-electromechanical systems (MEMS and NEMS)-based drug delivery devices have become commercially-feasible due to converging technologies and regulatory accommodation. The FDA Office of Combination Products coordinates review of innovative medical therapies that join elements from multiple established categories: drugs, devices, and biologics. Combination products constructed using MEMS or NEMS technology offer revolutionary opportunities to address unmet medical needs related to dosing. These products have the potential to completely control drug release, meeting requirements for on-demand pulsatile or adjustable continuous administration for extended periods. MEMS or NEMS technologies, materials science, data management, and biological science have all significantly developed in recent years, providing a multidisciplinary foundation for developing integrated therapeutic systems. If small-scale biosensor and drug reservoir units are combined and implanted, a wireless integrated system can regulate drug release, receive sensor feedback, and transmit updates. For example, an "artificial pancreas" implementation of an integrated therapeutic system would improve diabetes management. The tools of microfabrication technology, information science, and systems biology are being combined to design increasingly sophisticated drug delivery systems that promise to significantly improve medical care.
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Affiliation(s)
- Mark Staples
- MicroCHIPS, Inc., 6-B Preston Court, Bedford, Massachusetts 01730, USA.
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13
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Abstract
OBJECTIVE To summarize current data on the magnitude, prevalence, variability, pathogenesis, and management of the dawn phenomenon in patients with diabetes mellitus. METHODS On the basis of the pertinent available literature and clinical experience, we propose a quantitative definition of the dawn phenomenon, discuss potential pathogenic mechanisms, and suggest management options. RESULTS The "dawn phenomenon" is a term used to describe hyperglycemia or an increase in the amount of insulin needed to maintain normoglycemia, occurring in the absence of antecedent hypoglycemia or waning insulin levels, during the early morning hours. To be clinically relevant, the magnitude of the dawn increase in blood glucose level should be more than 10 mg/dL or the increase in insulin requirement should be at least 20% from the overnight nadir. Controversy exists regarding the frequency, reproducibility, and pathogenesis of the dawn phenomenon. Approximately 54% of patients with type 1 diabetes and 55% of patients with type 2 diabetes experience the dawn phenomenon when the foregoing quantitative definition is used. The most likely pathogenic mechanism underlying the dawn phenomenon is growth hormone-mediated impairment of insulin sensitivity at the liver and muscles. The exact biochemical pathways involved are unknown. Therapeutic decisions aimed at correcting fasting hyperglycemia should take into account the variability and magnitude of the dawn phenomenon within individual patients. Successful insulinization appears to minimize the effects of the dawn phenomenon. Currently, no subcutaneous depot preparation of insulin exists that is capable of mimicking the basal insulinsecretion of the healthy pancreas. CONCLUSION Increases in the bedtime doses of hypoglycemic agents with nighttime peaks in action may correct early morning hyperglycemia but be associated with undesirable nocturnal hypoglycemia. Targeted continuous subcutaneous insulin infusion programming can facilitate the prevention of early morning hyperglycemia in selected patients.
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Affiliation(s)
- Mary F Carroll
- Endocrinology and Metabolism Clinic, Eastern New Mexico Medical Center, Roswell, New Mexico, USA
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14
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Peppas N. Is there a future in glucose-sensitive, responsive insulin delivery systems? J Drug Deliv Sci Technol 2004. [DOI: 10.1016/s1773-2247(04)50045-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Affiliation(s)
- E Van Cauter
- Department of Medicine, University of Chicago, Illinois 60637, USA
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16
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17
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Affiliation(s)
- J Brange
- Novo Nordisk A/S, Bagsvaerd, Denmark
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18
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Silvestri S, Lu MY, Johnson H. Kinetics and mechanisms of peptide aggregation. I: Aggregation of a cholecystokinin analogue. J Pharm Sci 1993; 82:689-93. [PMID: 8360841 DOI: 10.1002/jps.2600820704] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Aggregation kinetics for a tetrapeptide analogue of cholecystokinin (A-71623) have been studied by quasi-elastic light scattering. Aggregation kinetics were quantitated with a kinetic model, described herein, which was modified for quasi-elastic light scattering data. The model predicts that the average molecular weight of peptide aggregates increases in a linear fashion with time. Data generated for A-71623 were consistent with the model presented under conditions of varied ethanol concentration at a fixed peptide concentration, as well as varied A-71623 concentration at fixed ethanol concentration. Although not the primary thrust of this study, experimental design permitted some understanding of the effect of environmental changes on the apparent aggregation kinetics of A-71623. These studies suggest A-71623 aggregation may be partially mediated by hydrophobic bonding.
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Affiliation(s)
- S Silvestri
- University of Pittsburgh, Department of Pharmaceutical Sciences, PA 15261
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19
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Boyle PJ, Avogaro A, Smith L, Shah SD, Cryer PE, Santiago JV. Absence of the dawn phenomenon and abnormal lipolysis in type 1 (insulin-dependent) diabetic patients with chronic growth hormone deficiency. Diabetologia 1992; 35:372-9. [PMID: 1516766 DOI: 10.1007/bf00401205] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To determine the role of growth hormone in overnight insulin requirements and lipolysis, five patients with chronic growth hormone deficiency and Type 1 (insulin-dependent) diabetes mellitus and six control patients with diabetes were each studied on two separate nights. Insulin was infused at a variable rate throughout one night to maintain euglycaemia and fixed at 04.00 hours on another. During the variable infusion, euglycaemia was maintained in control patients by a 36% increase in insulin infusion rate between 03.00 and 08.00 hours while a 46% decrease in the rate was required in growth hormone deficient patients (p less than 0.02). Despite this difference, mean free insulin values were equivalent. This finding is suggestive of increased insulin clearance in growth hormone sufficient patients. Glucose levels rose in control and fell in growth hormone deficient patients when insulin infusion rates were fixed at 04.00 hours. Glycerol production and non-esterified fatty acid concentrations were significantly lower in the growth hormone deficient diabetic patients, p less than 0.001, and when normalized with a heparin infusion, had no effect on insulin requirements. We conclude that: (1) growth hormone contributes to the development of the "dawn phenomenon," possibly by increasing insulin clearance (2) growth hormone helps sustain nocturnal lipolysis in Type 1 diabetes and (3) non-esterified fatty acids are not involved in the dawn phenomenon.
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Affiliation(s)
- P J Boyle
- Department of Medicine, University of New Mexico, Albuquerque
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20
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Perriello G, De Feo P, Torlone E, Fanelli C, Santeusanio F, Brunetti P, Bolli GB. The dawn phenomenon in type 1 (insulin-dependent) diabetes mellitus: magnitude, frequency, variability, and dependency on glucose counterregulation and insulin sensitivity. Diabetologia 1991; 34:21-8. [PMID: 2055337 DOI: 10.1007/bf00404020] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In 114 subjects with Type 1 (insulin-dependent) diabetes mellitus the nocturnal insulin requirements to maintain euglycaemia were assessed by means of i.v. insulin infusion by a Harvard pump. The insulin requirements decreased after midnight to a nadir of 0.102 +/- 0.03 mU.kg-1.min-1 at 02.40 hours. Thereafter, the insulin requirements increased to a peak of 0.135 +/- 0.06 mU.kg-1.min-1 at 06.40 hours (p less than 0.05). The dawn phenomenon (increase in insulin requirements by more than 20% after 02.40 hours lasting for at least 90 min) was present in 101 out of the 114 diabetic subjects, and its magnitude (% increase in insulin requirements between 05.00-07.00 hours vs that between 01.00-03.00 hours) was 19.4 +/- 0.54% and correlated inversely with the duration of diabetes (r = -0.72, p less than 0.001), but not with age. The nocturnal insulin requirements and the dawn phenomenon were highly reproducible on three separate nights. In addition, glycaemic control, state of counterregulation to hypoglycaemia and insulin sensitivity all influenced the magnitude of the dawn phenomenon as follows. In a subgroup of 84 subjects with Type 1 diabetes, the multiple correlation analysis showed that not only duration of diabetes (t = -9.76, p less than 0.0001), but also % HbA1 significantly influenced the magnitude of the dawn phenomenon (t = 2.03, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G Perriello
- Istituto di Patologia Medicare Metodologia Clinica, dell' Universita' degli Studi, Perugia, Italy
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21
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Edge JA, Matthews DR, Dunger DB. The dawn phenomenon is related to overnight growth hormone release in adolescent diabetics. Clin Endocrinol (Oxf) 1990; 33:729-37. [PMID: 2096008 DOI: 10.1111/j.1365-2265.1990.tb03910.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have investigated the relation between nocturnal insulin requirements and nocturnal growth hormone (GH) release in 26 diabetic adolescents at various puberty stages and have examined the effect of nocturnal GH suppression on pre-breakfast insulin requirement. In all the studies, euglycaemia was maintained overnight using a computer-calculated variable-rate insulin infusion, and 15-min blood samples were collected for GH assay. During initial clamp studies, insulin infusion rates were greater from 0500-0800 h (15.22 +/- 0.95 mU/kg/h, mean +/- SEM) than from 0100-0400 h (12.42 +/- 0.84 mU/kg/h, P less than 0.001). The increase in insulin infusion rate correlated with mean overnight GH concentration (r = 0.68, P less than 0.001), and was maximal at puberty stage 3 in both sexes. In seven of the subjects, a second identical clamp was performed following administration of 100 mg oral pirenzepine. During these studies, mean overnight GH levels were reduced by 11-85%, from 17.6 +/- 1.6 to 7.5 +/- 2.2 mU/l; P less than 0.01. Insulin requirements were not significantly different between the periods 0100-0400 and 0500-0800 h during these studies, and the reduction in pre-breakfast (0500-0800 h) insulin requirement when compared with the baseline studies correlated with the fall in GH secretion (rs = 0.82, P less than 0.01). The dawn increase in insulin requirement in adolescents with IDDM is related to the overnight GH secretion during puberty, and pre-breakfast insulin requirement can be reduced by suppressing nocturnal GH release.
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Affiliation(s)
- J A Edge
- Department of Paediatrics, John Radcliffe Hospital, Oxford, UK
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22
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Perriello G, De Feo P, Torlone E, Fanelli C, Santeusanio F, Brunetti P, Bolli GB. Nocturnal spikes of growth hormone secretion cause the dawn phenomenon in type 1 (insulin-dependent) diabetes mellitus by decreasing hepatic (and extrahepatic) sensitivity to insulin in the absence of insulin waning. Diabetologia 1990; 33:52-9. [PMID: 2406181 DOI: 10.1007/bf00586461] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The aim of the present studies was to test the hypothesis that the dawn phenomenon in Type 1 (insulin-dependent) diabetes mellitus is due to a decrease in insulin sensitivity caused by nocturnal spikes of growth hormone. Twelve subjects with Type 1 diabetes were studied on two different occasions, from 24.00 to 02.00 hours, and from 06.00 to 08.00 hours with the euglycaemic clamp technique at two plasma free insulin levels (approximately 25 mU/l, n = 7; approximately 80 mU/l, n = 5). To eliminate the confounding factor of insulin waning of previous Biostator studies, prior to clamp experiments the diabetic subjects were infused with i.v. insulin by means of a syringe pump according to their minute-to-minute insulin requirements. Insulin sensitivity decreased at dawn as compared to the early night hours (approximately 30% increase in the rate of hepatic glucose production, approximately 25% decrease in the rate of peripheral glucose utilisation). Plasma insulin clearance did not change overnight. In seven Type 1 diabetic subjects, suppression of nocturnal spikes of growth hormone secretion by somatostatin during basal glucagon and growth hormone replacement resulted in complete abolition of the increased rate of hepatic glucose production at dawn. Replacement of nocturnal spikes of growth hormone faithfully reproduced the increase in hepatic glucose production at dawn of the control study.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G Perriello
- Instituto di Patologia Speciale Medica, Università di Perugia, Italy
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Abstract
Recombinant DNA technology has now made it possible to produce proteins for pharmaceutical applications. Consequently, proteins produced via biotechnology now comprise a significant portion of the drugs currently under development. Isolation, purification, formulation, and delivery of proteins represent significant challenges to pharmaceutical scientists, as proteins possess unique chemical and physical properties. These properties pose difficult stability problems. A summary of both chemical and physical decomposition pathways for proteins is given. Chemical instability can include proteolysis, deamidation, oxidation, racemization, and beta-elimination. Physical instability refers to processes such as aggregation, precipitation, denaturation, and adsorption to surfaces. Current methodology to stabilize proteins is presented, including additives, excipients, chemical modification, and the use of site-directed mutagenesis to produce a more stable protein species.
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Affiliation(s)
- M C Manning
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence 66045
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24
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Beaufrère B, Beylot M, Metz C, Ruitton A, François R, Riou JP, Mornex R. Dawn phenomenon in type 1 (insulin-dependent) diabetic adolescents: influence of nocturnal growth hormone secretion. Diabetologia 1988; 31:607-11. [PMID: 3065115 DOI: 10.1007/bf00264768] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In order to reassess the role of growth hormone in the dawn phenomenon, we studied eight C-peptide negative diabetic adolescents, who are likely to exhibit important nocturnal growth hormone surges. The insulin infusion rate necessary to maintain euglycaemia was predetermined in each patient from 22.00 hours to 01.00 hours, and then kept constant until 08.00 hours resulting in stable free insulin levels. Blood glucose rose from 4.3 +/- 0.7 mmol/l at 01.00 hours to 7.1 +/- 1.1 mmol/l at 08.00 hours (p less than 0.01) secondary to an increased hepatic glucose production. All the subjects presented an important growth hormone secretion, ranging from 20 to 66 ng/ml (peak values) and from 3619 to 8621 ng.min.ml-1 (areas under the curve). The insulin infusion rate selected for each patient was positively correlated with the nocturnal growth hormone secretion (area under the curve) (r = 0.87, p less than 0.01). On the other hand, there was no relationship between the nocturnal growth hormone secretion and the magnitude of the early morning blood glucose rise (r = -0.48, p greater than 0.2). We conclude that, in Type 1 (insulin-dependent) diabetic adolescents, the dawn phenomenon exists but is moderate despite important growth hormone surges; the nocturnal growth hormone secretion influences the nocturnal insulin requirements but not the dawn phenomenon itself, if insulinisation is adequate.
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Affiliation(s)
- B Beaufrère
- INSERM U. 197, Faculté de Médecine Alexis Carrel, Lyon, France
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De Feo P, Perriello G, Bolli GB. Somogyi and dawn phenomena: mechanisms. DIABETES/METABOLISM REVIEWS 1988; 4:31-49. [PMID: 3278873 DOI: 10.1002/dmr.5610040106] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- P De Feo
- Istituto di Patologia Speciale Medica, Università degli Studi di, Perugia, Italy
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Nestler JE, Clore JN, Blackard WG. Reduced insulin clearance in normal subjects due to extreme hyperinsulinemia. Am J Med Sci 1988; 295:15-22. [PMID: 3276188 DOI: 10.1097/00000441-198801000-00005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Insulin clearance was assessed in five normal subjects infused with insulin at a rate of 10 mU.kg-1.min-1 for 12-16 hours, which produced insulin levels of 1500-2000 microU/ml (approximately 10(-8) M). This level approximates the Kd of low affinity insulin binding sites, whereas previous clearance studies had been performed at insulin concentrations of 10(-9) M or less, approximating the Kd of the high affinity insulin receptor. The metabolic clearance rate for insulin during the infusion averaged 214 +/- 29 ml.min-1.m-2, which is half of that reported previously when lower insulin levels were achieved. Upon termination of the insulin infusion, the disappearance of insulin was markedly prolonged with an average "half-life" of 62 minutes. The rapidity with which hyperinsulinemia altered clearance suggested that down-regulation of insulin receptors was probably not the explanation for the reduced clearance. To elucidate the cause for the observed decrease in insulin clearance, five additional subjects were studied. If insulin was infused for 3.0-4.5 hours, the half-life of insulin disappearance was intermediate between that for an insulin bolus dose and that for a 12-16 hour insulin infusion. Administration of an insulin bolus dose at the end of a 12-hour infusion, while the insulin concentration was still approximately 10(-8) M, or 140 min later, when the insulin concentration was 10(-9) M, was followed by rapid disappearance with half-lives of 1.5 and 6-8 minutes, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J E Nestler
- Department of Medicine, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298
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Perriello G, De Feo P, Bolli GB. The dawn phenomenon: nocturnal blood glucose homeostasis in insulin-dependent diabetes mellitus. Diabet Med 1988; 5:13-21. [PMID: 2964322 DOI: 10.1111/j.1464-5491.1988.tb00934.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- G Perriello
- Istituto di Patologia Speciale Medica e Metodologia Clinica, Universita degli Studi di Perugia, Italy
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De Feo P, Perriello G, Ventura MM, Calcinaro F, Basta G, Lolli C, Cruciani C, Dell'Olio A, Santeusanio F, Brunetti P. Studies on overnight insulin requirements and metabolic clearance rate of insulin in normal and diabetic man: relevance to the pathogenesis of the dawn phenomenon. Diabetologia 1986; 29:475-80. [PMID: 3530862 DOI: 10.1007/bf00453496] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In order to assess whether the metabolic clearance of insulin changes overnight, 11 patients with Type 1 (insulin-dependent) diabetes and low insulin antibody titre, and 6 nondiabetic subjects were studied. In these studies insulin was always infused by a Harvard pump. Initially, the nocturnal insulin requirements were assessed in the diabetic patients by an overnight feedback insulin infusion to maintain euglycaemia. The insulin requirements decreased continuously after midnight to a nadir of 0.115 +/- 0.014 mU X kg-1 X min-1 at 04.30 hours, but after 05.00 hours the insulin requirements increased nearly 40 percent to a maximum of 0.16 +/- 0.012 mU X kg-1 X min-1 at 07.00 hours. To assess whether plasma insulin clearance changes overnight, the diabetic patients were studied on two different occasions, from 22.00-02.30 hours and from 04.00-08.30 hours. During each of these two studies insulin was infused in sequential steps of 90 min each at the rate of 0.13, 0.40 and 0.20 mU X kg-1 X min-1. Despite changes in plasma free insulin concentration, the metabolic clearance of insulin in the interval 22.00-02.30 hours (12.6 +/- 0.17 ml X kg-1 X min-1) was no different from that of the interval 04.00-08.30 hours (12.5 +/- 0.19 ml X kg-1 X min-1). The nondiabetic subjects were studied on two different occasions to assess whether the metabolic clearance of insulin changes overnight. Somatostatin (0.25 mg/h) and insulin (0.3 mU X kg-1 X min-1) were infused from 22.00-02.30 hours on one occasion, and from 04.00-08.30 hours on the other.(ABSTRACT TRUNCATED AT 250 WORDS)
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Fukagawa NK, Minaker KL, Rowe JW, Goodman MN, Matthews DE, Bier DM, Young VR. Insulin-mediated reduction of whole body protein breakdown. Dose-response effects on leucine metabolism in postabsorptive men. J Clin Invest 1985; 76:2306-11. [PMID: 3908486 PMCID: PMC424354 DOI: 10.1172/jci112240] [Citation(s) in RCA: 282] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In vivo effects of insulin on plasma leucine and alanine kinetics were determined in healthy postabsorptive young men (n = 5) employing 360-min primed, constant infusions of L-[1-13C]leucine and L-[15N]alanine during separate single rate euglycemic insulin infusions. Serum insulin concentrations of 16.4 +/- 0.8, 29.1 +/- 2.7, 75.3 +/- 5.0, and 2,407 +/- 56 microU/ml were achieved. Changes in plasma 3-methyl-histidine (3-MeHis) were obtained as an independent qualitative indicator of insulin-mediated reduction in proteolysis. Hepatic glucose output was evaluated at the lowest insulin level using D-[6,6-2H2]glucose. The data demonstrate a dose-response effect of insulin to reduce leucine flux, from basal values of 77 +/- 1 to 70 +/- 2, 64 +/- 3, 57 +/- 3, and 52 +/- 4 mumol(kg X h)-1 at the 16, 29, 75, and 2,407 microU/ml insulin levels, respectively (P less than 0.01). A parallel, progressive reduction in 3-MeHis from 5.8 +/- 0.3 to 4.3 +/- 0.3 microM was revealed. Leucine oxidation estimated from the 13C-enrichment of expired CO2 and plasma leucine (12 +/- 1 mumol[kg X h]-1) and from the 13C-enrichment of CO2 and plasma alpha-ketoisocaproate (19 +/- 2 mumol[kg X h]-1) increased at the 16 microU/ml insulin level to 16 +/- 1 and 24 +/- 2 mumol(kg X h)-1, respectively (P less than 0.05 for each), but did not increase at higher insulin levels. Alanine flux (206 +/- 13 mumol(kg X h)-1) did not increase during the clamp, but alanine de novo synthesis increased in all studies from basal rates of 150 +/- 13 to 168 +/- 23, 185 +/- 21, 213 +/- 29, and 187 +/- 15 mumol(kg X h)-1 at 16, 29, 75, and 2,407 microU/ml insulin levels, respectively (P less than 0.05). These data indicate the presence of insulin-dependent suppression of leucine entry into the plasma compartment in man secondary to a reduction in proteolysis and the stimulation of alanine synthesis during euglycemic hyperinsulinemia.
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