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Thrasher JR, Arrieta A, Niu F, Cameron KR, Cordero TL, Shin J, Rhinehart AS, Vigersky RA. Early Real-World Performance of the MiniMed™ 780G Advanced Hybrid Closed-Loop System and Recommended Settings Use in the United States. Diabetes Technol Ther 2024; 26:24-31. [PMID: 38377317 DOI: 10.1089/dia.2023.0453] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Background: The MiniMed™ 780G system (MM780G) with Guardian™ 4 sensor includes a 100 mg/dL glucose target (GT) and automated insulin corrections up to every 5 min and was recently approved for use in the United States. In the present study, early real-world MM780G performance and the use of recommended system settings (100 mg/dL GT with an active insulin time of 2 h), by individuals with type 1 diabetes, were evaluated. Methods: CareLink™ personal data uploaded between the launch of the MM780G to August 22, 2023 were aggregated and underwent retrospective analysis (based on user consent) and if users had ≥10 days of continuous glucose monitoring (CGM) data. The 24-h day CGM metrics, including mean glucose, percentage of time spent in (%TIR), above (%TAR), and below (%TBR) target range (70-180 mg/dL), in addition to delivered insulin and closed-loop (CL) exits, were compared between an overall group (n = 7499) and individuals who used recommended settings (each, for >95% of the time). An analysis of the same metrics for MiniMed™ 770G system (MM770G) users (n = 3851) who upgraded to the MM780G was also conducted (paired t-test or Wilcoxon signed-rank test, P < 0.05 considered statistically significant). Results: For MM780G users, CGM use, and time in CL were >90% and all MM780G CGM metrics exceeded consensus-recommended goals. With recommended settings (22% of all users), mean %TIR and %TITR (70-140 mg/dL) were 81.4% and 56.4%, respectively. For individuals who upgraded from the MM770G, %TIR and %TITR increased from 73.2% to 78.3% and 45.8% to 52.6%, respectively, while %TAR reduced from 25.1% to 20.2% (P < 0.001, for all three). CL exits/week averaged <1, for all MM780G users. Conclusions: Early real-world MM780G use in the United States demonstrated a high percentage of time in range with low time above and below range. These outcomes are similar to those observed for real-world MM780G use in other countries.
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Affiliation(s)
- James R Thrasher
- Arkansas Diabetes and Endocrinology Center, Little Rock, Arkansas, USA
| | - Arcelia Arrieta
- Medtronic International Trading Sàrl, Tolochenaz, Switzerland
| | - Fang Niu
- Medtronic Diabetes, Northridge, California, USA
| | | | | | - John Shin
- Medtronic Diabetes, Northridge, California, USA
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Pihoker C, Shulman DI, Forlenza GP, Kaiserman KB, Sherr JL, Thrasher JR, Buckingham BA, Kipnes MS, Bode BW, Carlson AL, Lee SW, Latif K, Liljenquist DR, Slover RH, Dai Z, Niu F, Shin J, Jonkers RAM, Roy A, Grosman B, Vella M, Cordero TL, McVean J, Rhinehart AS, Vigersky RA. Safety and Glycemic Outcomes During the MiniMed TM Advanced Hybrid Closed-Loop System Pivotal Trial in Children and Adolescents with Type 1 Diabetes. Diabetes Technol Ther 2023; 25:755-764. [PMID: 37782145 DOI: 10.1089/dia.2023.0255] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Background: During MiniMed™ advanced hybrid closed-loop (AHCL) use by adolescents and adults in the pivotal trial, glycated hemoglobin (A1C) was significantly reduced, time spent in range (TIR) was significantly increased, and there were no episodes of severe hypoglycemia or diabetic ketoacidosis (DKA). The present study investigated the same primary safety and effectiveness endpoints during AHCL use by a younger cohort with type 1 diabetes (T1D). Methods: An intention-to-treat population (N = 160, aged 7-17 years) with T1D was enrolled in a single-arm study at 13 investigational centers. There was a run-in period (∼25 days) using HCL or sensor-augmented pump with/without predictive low-glucose management, followed by a 3-month study period with AHCL activated at two glucose targets (GTs; 100 and 120 mg/dL) for ∼45 days each. The mean ± standard deviation values of A1C, TIR, mean sensor glucose (SG), coefficient of variation (CV) of SG, time at SG ranges, and insulin delivered between run-in and study were analyzed (Wilcoxon signed-rank test or t-test). Results: Compared with baseline, AHCL use was associated with reduced A1C from 7.9 ± 0.9% (N = 160) to 7.4 ± 0.7% (N = 136) (P < 0.001) and overall TIR increased from the run-in 59.4 ± 11.8% to 70.3 ± 6.5% by end of study (P < 0.001), without change in CV, time spent below range (TBR) <70 mg/dL, or TBR <54 mg/dL. Relative to longer active insulin time (AIT) settings (N = 52), an AIT of 2 h (N = 19) with the 100 mg/dL GT increased mean TIR to 73.4%, reduced TBR <70 mg/dL from 3.5% to 2.2%, and reduced time spent above range (TAR) >180 mg/dL from 28.7% to 24.4%. During AHCL use, there was no severe hypoglycemia or DKA. Conclusions: In children and adolescents with T1D, MiniMed AHCL system use was safe, A1C was lower, and TIR was increased. The lowest GT and shortest AIT were associated with the highest TIR and lowest TBR and TAR, all of which met consensus-recommended glycemic targets. ClinicalTrials.gov ID: NCT03959423.
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Affiliation(s)
- Catherine Pihoker
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Dorothy I Shulman
- University of South Florida, Pediatric Diabetes and Endocrinology, Tampa, Florida, USA
| | - Gregory P Forlenza
- Department of Pediatrics, Barbara Davis Center of Childhood Diabetes, Aurora, Colorado, USA
| | | | - Jennifer L Sherr
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - James R Thrasher
- Arkansas Diabetes and Endocrinology Center, Little Rock, Arkansas, USA
| | - Bruce A Buckingham
- Stanford University School of Medicine, Pediatric Diabetes and Endocrinology, Stanford, California, USA
| | - Mark S Kipnes
- Diabetes and Glandular Disease Clinic, San Antonio, Texas, USA
| | - Bruce W Bode
- Atlanta Diabetes Associates, Atlanta, Georgia, USA
| | - Anders L Carlson
- International Diabetes Center, HealthPartners Institute, Minneapolis, Minnesota, USA
| | - Scott W Lee
- Department of Endocrinology, Loma Linda University, Loma Linda, California, USA
| | - Kashif Latif
- AM Diabetes and Endocrinology Center, Bartlett, Tennessee, USA
| | | | - Robert H Slover
- Department of Pediatrics, Barbara Davis Center of Childhood Diabetes, Aurora, Colorado, USA
| | - Zheng Dai
- Medtronic, Northridge, California, USA
| | - Fang Niu
- Medtronic, Northridge, California, USA
| | - John Shin
- Medtronic, Northridge, California, USA
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Cordero TL, Dai Z, Arrieta A, Niu F, Vella M, Shin J, Rhinehart AS, McVean J, Lee SW, Slover RH, Forlenza GP, Shulman DI, Pop-Busui R, Thrasher JR, Kipnes MS, Christiansen MP, Buckingham BA, Pihoker C, Sherr JL, Kaiserman KB, Vigersky RA. Glycemic Outcomes During Early Use of the MiniMed™ 780G Advanced Hybrid Closed-Loop System with Guardian™ 4 Sensor. Diabetes Technol Ther 2023; 25:652-658. [PMID: 37252734 PMCID: PMC10460682 DOI: 10.1089/dia.2023.0123] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Background: Safety and significant improvement in overall glycated hemoglobin (A1C) and percentage of time spent in (TIR), below (TBR), and above (TAR) glucose range were demonstrated in the pivotal trial of adolescents and adults using the MiniMed™ advanced hybrid closed-loop (AHCL) system with the adjunctive, calibration-required Guardian™ Sensor 3. The present study evaluated early outcomes of continued access study (CAS) participants who transitioned from the pivotal trial investigational system to the approved MiniMed™ 780G system with the non-adjunctive, calibration-free Guardian™ 4 Sensor (MM780G+G4S). Study data were presented alongside those of real-world MM780G+G4S users from Europe, the Middle East, and Africa. Methods: The CAS participants (N = 109, aged 7-17 years and N = 67, aged >17 years) used the MM780G+G4S for 3 months and data of real-world MM780G+G4S system users (N = 10,204 aged ≤15 years and N = 26,099 aged >15 years) were uploaded from September 22, 2021 to December 02, 2022. At least 10 days of real-world continuous glucose monitoring (CGM) data were required for analyses. Glycemic metrics, delivered insulin and system use/interactions underwent descriptive analyses. Results: Time in AHCL and CGM use were >90% for all groups. AHCL exits averaged 0.1/day and there were few blood glucose measurements (BGMs) (0.8/day-1.0/day). Adults in both cohorts met most consensus recommendations for glycemic targets. Pediatric groups met recommendations for %TIR and %TBR, although not those for mean glucose variability and %TAR, possibly due to low use of recommended glucose target (100 mg/dL) and active insulin time (2 h) settings (28.4% in the CAS cohort and 9.4% in the real-world cohort). The CAS pediatric and adult A1C were 7.2% ± 0.7% and 6.8% ± 0.7%, respectively, and there were no serious adverse events. Conclusions: Early clinical use of the MM780G+G4S was safe and involved minimal BGMs and AHCL exits. Consistent with real-world pediatric and adult use, outcomes were associated with achievement of recommended glycemic targets. Clinical Trial Registration number: NCT03959423.
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Affiliation(s)
| | - Zheng Dai
- Medtronic, Northridge, California, USA
| | - Arcelia Arrieta
- Medtronic International Trading Sàrl, Tolochenaz, Switzerland
| | - Fang Niu
- Medtronic, Northridge, California, USA
| | | | - John Shin
- Medtronic, Northridge, California, USA
| | | | | | - Scott W. Lee
- Department of Endocrinology, Loma Linda University, Loma Linda, California, USA
| | - Robert H. Slover
- Department of Pediatrics, Barbara Davis Center of Childhood Diabetes, Aurora, Colorado, USA
| | - Gregory P. Forlenza
- Department of Pediatrics, Barbara Davis Center of Childhood Diabetes, Aurora, Colorado, USA
| | - Dorothy I. Shulman
- University of South Florida Diabetes and Endocrinology, Department of Pediatrics, Tampa, Florida, USA
| | - Rodica Pop-Busui
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - James R. Thrasher
- Arkansas Diabetes and Endocrinology Center, Little Rock, Arkansas, USA
| | - Mark S. Kipnes
- Diabetes and Glandular Disease Clinic, San Antonio, Texas, USA
| | | | - Bruce A. Buckingham
- Stanford University School of Medicine, Department of Pediatric Endocrinology, Stanford, California, USA
| | - Catherine Pihoker
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Jennifer L. Sherr
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA
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Brazg R, Garg SK, Bhargava A, Thrasher JR, Latif K, Bode BW, Bailey TS, Horowitz BS, Cavale A, Kudva YC, Kaiserman KB, Grunberger G, Reed JC, Chattaraj S, Zhang G, Shin J, Chen V, Lee SW, Cordero TL, Rhinehart AS, Vigersky RA, Buckingham BA. Evaluation of Extended Infusion Set Performance in Adults with Type 1 Diabetes: Infusion Set Survival Rate and Glycemic Outcomes from a Pivotal Trial. Diabetes Technol Ther 2022; 24:535-543. [PMID: 35263188 PMCID: PMC9353978 DOI: 10.1089/dia.2021.0540] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Background: Standard insulin infusion sets (IISs) are to be replaced every 2 to 3 days to avoid complications and diabetic ketosis due to set failure. This pivotal trial evaluated the safety and performance of a new extended-wear infusion set (EIS) when used for 7 days by adults with type 1 diabetes (T1D). Methods: This single-arm, nonrandomized trial enrolled adults (18-80 years of age) with T1D, who used their own MiniMed™ 670G system with insulin lispro or insulin aspart and the EIS for up to 7 days, across 12 consecutive wears. Safety endpoints included incidence of serious adverse events (SAEs), serious adverse device effects (SADEs), unanticipated adverse device effects (UADEs), severe hypoglycemia (SevHypo), severe hyperglycemia (SevHyper), diabetic ketoacidosis (DKA), and skin infection. The EIS failure rate due to unexplained hyperglycemia (i.e., suspected occlusion), the overall EIS survival rate, glycemic control outcomes (i.e., A1C, mean sensor glucose and time spent in established glucose ranges), total daily insulin delivered, and satisfaction with the EIS were determined. Results: The intention to treat population (n = 259, 48% men, 45.0 ± 14.1 years) wore a total of 3041 EIS devices. No SADE, UADE, or DKA events was reported. Overall rates of SAEs, SevHypo, SevHyper, and skin infection were 3.8, 2.5, 104.1, and 20.1 events per 100 participant-years. The rate of EIS failure due to unexplained hyperglycemia at the end of day 7 was 0.1% (95% confidence interval [CI]: 0.03-0.51) and 0.4% (95% CI: 0.16-1.00) for insulin lispro and aspart use, respectively. Overall EIS survival rate at the end of day 7 was 77.8% (95% CI: 76.2-79.3), glycemic control did not change, and participants reported greater satisfaction with the EIS compared with standard IISs worn before the study (P < 0.001). Conclusions: This investigation demonstrates that the EIS, when worn for up to 7 days, was safe and rated with high satisfaction, without adversely affecting glycemic control in adults with T1D. Clinical Trial Registration number: NCT04113694 (https://clinicaltrials.gov/ct2/show/NCT04113694).
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Affiliation(s)
- Ron Brazg
- Rainier Clinical Research Center, Renton, Washington, USA
| | - Satish K. Garg
- Barbara Davis Center for Diabetes, Aurora, Colorado, USA
| | - Anuj Bhargava
- Iowa Diabetes and Endocrinology Center, West Des Moines, Iowa, USA
| | | | - Kashif Latif
- AM Diabetes and Endocrinology Center, Bartlett, Tennessee, USA
| | | | | | | | - Arvind Cavale
- Diabetes and Endocrinology Consultants of Pennsylvania, Feasterville Trevose, Pennsylvania, USA
| | | | | | | | | | | | | | - John Shin
- Medtronic, Northridge, California, USA
| | | | | | | | | | | | - Bruce A. Buckingham
- Stanford University School of Medicine, Palo Alto, California, USA
- Address correspondence to: Bruce A. Buckingham, MD, Professor Emeritus - Active, Center for Academic Medicine, Pediatric Endocrinology, MC: 5660, Stanford University School of Medicine, 453 Quarry Road, Room 354, Palo Alto, CA 94304, USA
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Carlson AL, Sherr JL, Shulman DI, Garg SK, Pop-Busui R, Bode BW, Lilenquist DR, Brazg RL, Kaiserman KB, Kipnes MS, Thrasher JR, Reed JHC, Slover RH, Philis-Tsimikas A, Christiansen M, Grosman B, Roy A, Vella M, Jonkers RA, Chen X, Shin J, Cordero TL, Lee SW, Rhinehart AS, Vigersky RA. Safety and Glycemic Outcomes During the MiniMed™ Advanced Hybrid Closed-Loop System Pivotal Trial in Adolescents and Adults with Type 1 Diabetes. Diabetes Technol Ther 2022; 24:178-189. [PMID: 34694909 PMCID: PMC8971997 DOI: 10.1089/dia.2021.0319] [Citation(s) in RCA: 93] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction: This trial assessed safety and effectiveness of an advanced hybrid closed-loop (AHCL) system with automated basal (Auto Basal) and automated bolus correction (Auto Correction) in adolescents and adults with type 1 diabetes (T1D). Materials and Methods: This multicenter single-arm study involved an intent-to-treat population of 157 individuals (39 adolescents aged 14-21 years and 118 adults aged ≥22-75 years) with T1D. Study participants used the MiniMed™ AHCL system during a baseline run-in period in which sensor-augmented pump +/- predictive low glucose management or Auto Basal was enabled for ∼14 days. Thereafter, Auto Basal and Auto Correction were enabled for a study phase (∼90 days), with glucose target set to 100 or 120 mg/dL for ∼45 days, followed by the other target for ∼45 days. Study endpoints included safety events and change in mean A1C, time in range (TIR, 70-180 mg/dL) and time below range (TBR, <70 mg/dL). Run-in and study phase values were compared using Wilcoxon signed-rank test or paired t-test. Results: Overall group time spent in closed loop averaged 94.9% ± 5.4% and involved only 1.2 ± 0.8 exits per week. Compared with run-in, AHCL reduced A1C from 7.5% ± 0.8% to 7.0% ± 0.5% (<0.001, Wilcoxon signed-rank test, n = 155), TIR increased from 68.8% ± 10.5% to 74.5% ± 6.9% (<0.001, Wilcoxon signed-rank test), and TBR reduced from 3.3% ± 2.9% to 2.3% ± 1.7% (<0.001, Wilcoxon signed-rank test). Similar benefits to glycemia were observed for each age group and were more pronounced for the nighttime (12 AM-6 AM). The 100 mg/dL target increased TIR to 75.4% (n = 155), which was further optimized at a lower active insulin time (AIT) setting (i.e., 2 h), without increasing TBR. There were no severe hypoglycemic or diabetic ketoacidosis events during the study phase. Conclusions: These findings show that the MiniMed AHCL system is safe and allows for achievement of recommended glycemic targets in adolescents and adults with T1D. Adjustments in target and AIT settings may further optimize glycemia and improve user experience. Clinical Trial Registration number: NCT03959423.
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Affiliation(s)
- Anders L. Carlson
- International Diabetes Center, HealthPartners Institute, Minneapolis, Minnesota, USA
| | - Jennifer L. Sherr
- Yale University School of Medicine Pediatric Endocrinology, New Haven, Connecticut, USA
| | - Dorothy I. Shulman
- University of South Florida Diabetes and Endocrinology, Tampa, Florida, USA
| | - Satish K. Garg
- Barbara Davis Center of Childhood Diabetes, Aurora, Colorado, USA
| | - Rodica Pop-Busui
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | | | | | - Ron L. Brazg
- Rainier Clinical Research Center, Renton, Washington, USA
| | | | - Mark S. Kipnes
- Diabetes and Glandular Disease Clinic, San Antonio, Texas, USA
| | - James R. Thrasher
- Arkansas Diabetes and Endocrinology Center, Little Rock, Arkansas, USA
| | | | - Robert H. Slover
- Barbara Davis Center of Childhood Diabetes, Aurora, Colorado, USA
| | | | | | | | | | | | | | | | - John Shin
- Medtronic, Northridge, California, USA
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Thrasher JR, Talley JD. Syncope and aortic valve stenosis: clues to diagnosis and pathophysiology. J Ark Med Soc 1996; 93:191-3. [PMID: 8840749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- J R Thrasher
- Department of Internal Medicine, UAMS Medical Center, USA
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8
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Thrasher JR, Cooper MD, Dunaway GA. Developmental changes in heart and muscle phosphofructokinase isozymes. J Biol Chem 1981; 256:7844-8. [PMID: 6455419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Phosphofructokinase isozymes of fetal, neonatal, and adult rat heart and skeletal muscle were characterized by DEAE-cellulose chromatography, agarose gel electrophoresis, and immunodiffusion with specific antisera. The results of these studies indicate that in skeletal muscle and heart the levels of the major liver phosphofructokinase isozyme (PFK-L2) and the muscle phosphofructokinase isozyme (PFK-M) are dependent on the developmental status of the rat. For example, PFK-L2 and PFK-M are present in fetal and early neonatal skeletal muscle; whereas in adult skeletal muscle, only PFK-M is detectable. By DEAE- cellulose chromatography, PFK-L2 activity was estimated to be 2.4 units/g (41% of total phosphofructokinase activity) in fetal muscle, very low and not resolved from PFK-M in 7-day neonatal muscle, and not detectable in adult muscle. Further, PFK-M activity was found to be 3.4 units/g (59% of total phosphofructokinase activity), 10 units/g, and 31.6 units/g in fetal, 7-day neonatal, and adult skeletal muscle, respectively. The developmental changes of heart phosphofructokinase isozymes differ considerably from that of the skeletal muscle phosphofructokinase isozymes. In fetal heart, PFK-L2 is the major phosphofructokinase isozyme (5.6 units/g), constituting 67% of total phosphofructokinase activity. Further, in fetal heart another phosphofructokinase isozyme (33% of total phosphofructokinase activity) was found by DEAE-cellulose chromatography which is different from PFK-M and PFK-L2. In 7-day neonatal and adult heart, PFK-M and PFK-L2 are the only detectable phosphofructokinase isozymes. Varying from 5.6 units/g (44% of total) in 7-day neonatal to 5.9 units/g (40% of total) in adult heart, PFK-L2 activity remains fairly constant. Also, PFK-M is very low in fetal heart but increases within 1 week postpartum to 5.5 units/g (50% of total activity) and to 8.9 units/g (60% of total activity) in adult heart.
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Dunaway GA, Leung GL, Thrasher JR, Naqui D, Morris HP. Regulation of rat liver phosphofructokinase levels in Morris hepatomas. Biochem Biophys Res Commun 1979; 88:882-6. [PMID: 157134 DOI: 10.1016/0006-291x(79)91491-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Dunaway GA, Leung GL, Thrasher JR, Cooper MD. Turnover of hepatic phosphofructokinase in normal and diabetic rats. Role of insulin and peptide stabilizing factor. J Biol Chem 1978; 253:7460-3. [PMID: 151683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Earlier work demonstrated that the activity of liver phosphofructokinase (PFK-L2) and immunoreactive PFK-L2 were decreased in diabetic rats and increased to normal or super-normal amounts following insulin treatment (Dunaway, G.A., and Weber, G., (1974) Arch. Biochem. Biophys. 162, 629-637). This report indicates that the decrease in levels of PFK-L2 in diabetic rats is a result of an accelerated degradation rate while the synthetic rate remains nearly normal. Following insulin treatment, the rate of PFK-L2 synthesis is enhanced 2-fold, whereas the rate of degradation appears to be greatly diminished. An inverse relationship is shown to exist between the PFK-L2 levels and the rates of PFK-L2 degradation, suggesting that the levels of PFK-L2 are primarily regulated by degradation rate. In addition, the levels of the PFK-L2 peptide stabilizing factor are inversely proportional to rates of PFK-L2 degradation. These results indicate that insulin mediates the rate of degradation of PFK-L2 by controlling the level of the peptide stabilizing factor.
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Dunaway GA, Leung GL, Cooper MD, Thrasher JR, Wagle SR. Distribution of hepatic phosphofructokinase isozymes in parenchymal and sinusoidal cells. Biochem Biophys Res Commun 1978; 80:71-4. [PMID: 146493 DOI: 10.1016/0006-291x(78)91105-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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