1
|
Fabricius TW, Verhulst CEM, Kristensen PL, Holst JJ, Tack CJ, McCrimmon RJ, Heller SR, Evans ML, de Galan BE, Pedersen-Bjergaard U. Counterregulatory hormone and symptom responses to hypoglycaemia in people with type 1 diabetes, insulin-treated type 2 diabetes or without diabetes: the Hypo-RESOLVE hypoglycaemic clamp study. Acta Diabetol 2024; 61:623-633. [PMID: 38376580 PMCID: PMC11055751 DOI: 10.1007/s00592-024-02239-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/13/2024] [Indexed: 02/21/2024]
Abstract
AIM The sympathetic nervous and hormonal counterregulatory responses to hypoglycaemia differ between people with type 1 and type 2 diabetes and may change along the course of diabetes, but have not been directly compared. We aimed to compare counterregulatory hormone and symptom responses to hypoglycaemia between people with type 1 diabetes, insulin-treated type 2 diabetes and controls without diabetes, using a standardised hyperinsulinaemic-hypoglycaemic clamp. MATERIALS We included 47 people with type 1 diabetes, 15 with insulin-treated type 2 diabetes, and 32 controls without diabetes. Controls were matched according to age and sex to the people with type 1 diabetes or with type 2 diabetes. All participants underwent a hyperinsulinaemic-euglycaemic-(5.2 ± 0.4 mmol/L)-hypoglycaemic-(2.8 ± 0.13 mmol/L)-clamp. RESULTS The glucagon response was lower in people with type 1 diabetes (9.4 ± 0.8 pmol/L, 8.0 [7.0-10.0]) compared to type 2 diabetes (23.7 ± 3.7 pmol/L, 18.0 [12.0-28.0], p < 0.001) and controls (30.6 ± 4.7, 25.5 [17.8-35.8] pmol/L, p < 0.001). The adrenaline response was lower in type 1 diabetes (1.7 ± 0.2, 1.6 [1.3-5.2] nmol/L) compared to type 2 diabetes (3.4 ± 0.7, 2.6 [1.3-5.2] nmol/L, p = 0.001) and controls (2.7 ± 0.4, 2.8 [1.4-3.9] nmol/L, p = 0.012). Growth hormone was lower in people with type 2 diabetes than in type 1 diabetes, at baseline (3.4 ± 1.6 vs 7.7 ± 1.3 mU/L, p = 0.042) and during hypoglycaemia (24.7 ± 7.1 vs 62.4 ± 5.8 mU/L, p = 0.001). People with 1 diabetes had lower overall symptom responses than people with type 2 diabetes (45.3 ± 2.7 vs 58.7 ± 6.4, p = 0.018), driven by a lower neuroglycopenic score (27.4 ± 1.8 vs 36.7 ± 4.2, p = 0.012). CONCLUSION Acute counterregulatory hormone and symptom responses to experimental hypoglycaemia are lower in people with type 1 diabetes than in those with long-standing insulin-treated type 2 diabetes and controls.
Collapse
Affiliation(s)
- Therese W Fabricius
- Department of Endocrinology and Nephrology, Nordsjællands Hospital, Hillerød, Denmark.
| | - Clementine E M Verhulst
- Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Peter L Kristensen
- Department of Endocrinology and Nephrology, Nordsjællands Hospital, Hillerød, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Cees J Tack
- Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Rory J McCrimmon
- Systems Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Simon R Heller
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
| | - Mark L Evans
- Welcome MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Bastiaan E de Galan
- Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
- Department of Internal Medicine, Maastricht UMC+, Maastricht, The Netherlands
- CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
| | - Ulrik Pedersen-Bjergaard
- Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
2
|
Michaelsson LF, la Cour JL, Medici BB, Watt T, Faber J, Nygaard B. Levothyroxine/Liothyronine Combination Therapy and Quality of Life: Is It All about Weight Loss? Eur Thyroid J 2018; 7:243-250. [PMID: 30374427 PMCID: PMC6198786 DOI: 10.1159/000490383] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 05/24/2018] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVES According to one hypothesis, the popularity of levothyroxine (L-T4)/liothyronine (L-T3) combination therapy relates to weight loss. The purpose of this study was to detect a possible correlation between thyroid-related quality of life (QoL) and weight loss in hypothyroid patients switched from L-T4 monotherapy to L-T4/L-T3 combination therapy. METHODS In an open-label cohort study, all hypothyroid patients referred to the University Hospital endocrine clinic due to persistent symptoms despite adequate L-T4 monotherapy (without other explanations for the symptoms) were switched from L-T4 monotherapy to L-T4/ L-T3 combination therapy at a ratio of approximately 17/1. At baseline and after 3 months of treatment we measured: QoL by the Thyroid Patient-Reported Outcome (ThyPRO-39) questionnaire, thyroid hormones, body weight, body composition by a DEXA-scan, and cognitive function by evaluating participants' reaction time as well as working memory by the California Computerized Assessment Package (CalCAP®). QoL was re-evaluated after 12 months. RESULTS Twenty-three patients participated (91% women, median age 47 years). The ThyPRO-39 composite score decreased from a median of 54 (quartiles: 34, 74) to 15 (11, 28) after 3 months (p < 0.0001), and 20 (14, 26) after 12 months, indicating a better QoL. There was no change in body weight, and no correlations between QoL and weight. There was a slight improvement in cognitive function, whereas body composition, heart rate, and serum TSH did not change. CONCLUSION Our study on hypothyroid patients switched from L-T4 monotherapy to L-T4/L-T3 combination therapy showed a substantial improvement in QoL measured by the ThyPRO-39. This improvement could not be explained by weight loss.
Collapse
Affiliation(s)
- Luba Freja Michaelsson
- Department of Endocrinology, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jeppe Lerche la Cour
- Department of Endocrinology, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
| | | | - Torquil Watt
- Department of Endocrinology, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jens Faber
- Department of Endocrinology, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Birte Nygaard
- Department of Endocrinology, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- *Birte Nygaard, Department of Endocrinology, Herlev Hospital, University of Copenhagen, Herlev Ringvej 75, DK–2730 Herlev (Denmark), E-Mail
| |
Collapse
|
3
|
Abstract
Hypoglycemia is defined by an abnormally low blood glucose level. The condition develops when rates of glucose entry into the systematic circulation are reduced relative to the glucose uptake by the tissues. A cardinal manifestation of hypoglycemia arises from inadequate supply of glucose to the brain, where glucose is the primary metabolic fuel. The brain is one of the first organs to be affected by hypoglycemia. Shortage of glucose in the brain, or neuroglycopenia, results in a gradual loss of cognitive functions causing slower reaction time, blurred speech, loss of consciousness, seizures, and ultimately death, as the hypoglycemia progresses. The electrical activity in the brain represents the metabolic state of the brain cells and can be measured by electroencephalography (EEG). An association between hypoglycemia and changes in the EEG has been demonstrated, although blood glucose levels alone do not seem to predict neuroglycopenia. This review provides an overview of the current literature regarding changes in the EEG during episodes of low blood glucose.
Collapse
Affiliation(s)
| | - Claus B Juhl
- HYPOSAFE A/S, Nymøllevej 6, 3540 Lynge, Denmark
- Department of Endocrinology, Hospital South West Jutland, Esbjerg, Denmark
| |
Collapse
|
4
|
Kristensen PL, Pedersen-Bjergaard U, Due-Andersen R, Høi-Hansen T, Grimmeshave L, Lyssenko V, Groop L, Holst JJ, Vaag AA, Thorsteinsson B. Impact of the TCF7L2 genotype on risk of hypoglycaemia and glucagon secretion during hypoglycaemia. Endocr Connect 2016; 5:53-60. [PMID: 27758844 PMCID: PMC5097143 DOI: 10.1530/ec-16-0050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 10/10/2016] [Indexed: 11/25/2022]
Abstract
INTRODUCTION In healthy carriers of the T allele of the transcription factor 7-like 2 (TCF7L2), fasting plasma glucagon concentrations are lower compared with those with the C allele. We hypothesised that presence of the T allele is associated with a diminished glucagon response during hypoglycaemia and a higher frequency of severe hypoglycaemia (SH) in type 1 diabetes (T1DM). MATERIAL AND METHODS This is a post hoc study of an earlier prospective observational study of SH and four mechanistic studies of physiological responses to hypoglycaemia. 269 patients with T1DM were followed in a one-year observational study. A log-linear negative binomial model was applied with events of SH as dependent variable and TCF7L2 alleles as explanatory variable. In four experimental studies including 65 people, TCF7L2 genotyping was done and plasma glucagon concentration during experimental hypoglycaemia was determined. RESULTS Incidences of SH were TT 0.54, TC 0.98 and CC 1.01 episodes per patient-year with no significant difference between groups. During experimental hypoglycaemia, the TCF7L2 polymorphism did not influence glucagon secretion. DISCUSSION Patients with T1DM carrying the T allele of the TCF7L2 polymorphism do not exhibit diminished glucagon response during hypoglycaemia and are not at increased risk of severe hypoglycaemia compared with carriers of the C allele.
Collapse
Affiliation(s)
- Peter L Kristensen
- Department of CardiologyNephrology and Endocrinology, Nordsjællands Hospital, Hillerød, Denmark
| | - Ulrik Pedersen-Bjergaard
- Department of CardiologyNephrology and Endocrinology, Nordsjællands Hospital, Hillerød, Denmark
- Faculty of Health and Medical SciencesUniversity of Copenhagen, Copenhagen, Denmark
| | - Rikke Due-Andersen
- Department of CardiologyNephrology and Endocrinology, Nordsjællands Hospital, Hillerød, Denmark
- Lægerne på EllemarksvejKøge, Denmark
| | - Thomas Høi-Hansen
- Department of CardiologyNephrology and Endocrinology, Nordsjællands Hospital, Hillerød, Denmark
- Department of CardiologyHerlev-Gentofte University Hospital, Herlev, Denmark
| | - Lise Grimmeshave
- Department of CardiologyNephrology and Endocrinology, Nordsjællands Hospital, Hillerød, Denmark
- Novo Nordisk A/SSøborg, Denmark
| | - Valeriya Lyssenko
- Steno Diabetes CenterGentofte, Denmark
- Lund University Diabetes CentreSkåne University Hospital, Malmø, Sweden
| | - Leif Groop
- Lund University Diabetes CentreSkåne University Hospital, Malmø, Sweden
- Finnish Institute for Molecular Medicine (FIMM)Helsinki University, Helsinki, Finland
| | - Jens J Holst
- Faculty of Health and Medical SciencesUniversity of Copenhagen, Copenhagen, Denmark
- Department of Biomedical SciencesNNF Center for Basic Metabolic Research, The Panum Institute, Copenhagen, Denmark
| | - Allan A Vaag
- Faculty of Health and Medical SciencesUniversity of Copenhagen, Copenhagen, Denmark
- Department of EndocrinologyCopenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Birger Thorsteinsson
- Department of CardiologyNephrology and Endocrinology, Nordsjællands Hospital, Hillerød, Denmark
- Faculty of Health and Medical SciencesUniversity of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
5
|
Sejling AS, Kjær TW, Pedersen-Bjergaard U, Diemar SS, Frandsen CSS, Hilsted L, Faber J, Holst JJ, Tarnow L, Nielsen MN, Remvig LS, Thorsteinsson B, Juhl CB. Hypoglycemia-associated changes in the electroencephalogram in patients with type 1 diabetes and normal hypoglycemia awareness or unawareness. Diabetes 2015; 64:1760-9. [PMID: 25488900 DOI: 10.2337/db14-1359] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 12/02/2014] [Indexed: 11/13/2022]
Abstract
Hypoglycemia is associated with increased activity in the low-frequency bands in the electroencephalogram (EEG). We investigated whether hypoglycemia awareness and unawareness are associated with different hypoglycemia-associated EEG changes in patients with type 1 diabetes. Twenty-four patients participated in the study: 10 with normal hypoglycemia awareness and 14 with hypoglycemia unawareness. The patients were studied at normoglycemia (5-6 mmol/L) and hypoglycemia (2.0-2.5 mmol/L), and during recovery (5-6 mmol/L) by hyperinsulinemic glucose clamp. During each 1-h period, EEG, cognitive function, and hypoglycemia symptom scores were recorded, and the counterregulatory hormonal response was measured. Quantitative EEG analysis showed that the absolute amplitude of the θ band and α-θ band up to doubled during hypoglycemia with no difference between the two groups. In the recovery period, the θ amplitude remained increased. Cognitive function declined equally during hypoglycemia in both groups and during recovery reaction time was still prolonged in a subset of tests. The aware group reported higher hypoglycemia symptom scores and had higher epinephrine and cortisol responses compared with the unaware group. In patients with type 1 diabetes, EEG changes and cognitive performance during hypoglycemia are not affected by awareness status during a single insulin-induced episode with hypoglycemia.
Collapse
Affiliation(s)
- Anne-Sophie Sejling
- Faculty of Health, University of Southern Denmark, Odense, Denmark Nordsjællands Hospital Hillerød, Hillerød, Denmark
| | - Troels W Kjær
- Roskilde Hospital, Roskilde, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Rigshospitalet, Copenhagen, Denmark
| | | | - Sarah S Diemar
- Nordsjællands Hospital Hillerød, Hillerød, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christian S S Frandsen
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Hvidovre Hospital, Hvidovre, Denmark
| | | | - Jens Faber
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Herlev Hospital, Herlev, Denmark
| | - Jens J Holst
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lise Tarnow
- Nordsjællands Hospital Hillerød, Hillerød, Denmark Health, Aarhus University, Aarhus, Denmark
| | | | | | - Birger Thorsteinsson
- Nordsjællands Hospital Hillerød, Hillerød, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claus B Juhl
- Faculty of Health, University of Southern Denmark, Odense, Denmark HypoSafe A/S, Lyngby, Denmark Sydvestjysk Sygehus, Esbjerg, Denmark
| |
Collapse
|
6
|
Færch LH, Thorsteinsson B, Tarnow L, Holst JJ, Kjær T, Kanters J, Larroude C, Dela F, Pedersen-Bjergaard U. Effects of angiotensin II receptor blockade on cerebral, cardiovascular, counter-regulatory, and symptomatic responses during hypoglycaemia in patients with type 1 diabetes. J Renin Angiotensin Aldosterone Syst 2014; 16:1036-45. [DOI: 10.1177/1470320314529356] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Louise H Færch
- Department of Cardiology, Nephrology and Endocrinology, Nordsjællands Hospital – Hillerød, Denmark
| | - Birger Thorsteinsson
- Department of Cardiology, Nephrology and Endocrinology, Nordsjællands Hospital – Hillerød, Denmark
- Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Lise Tarnow
- HIH Research Unit, Nordsjællands Hospital – Hillerød, Denmark
- Department of Health, University of Aarhus, Denmark
| | - Jens Juul Holst
- NNF Centre for Basic Metabolic Research, Department of Biomedical Sciences, the Panum Institute, University of Copenhagen, Denmark
| | - Troels Kjær
- Clinic of Neurophysiology, The Neuroscience Centre, Rigshospitalet, Copenhagen University Hospital, Denmark
| | - Jørgen Kanters
- Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Denmark
- Department of Cardiology, Nephrology and Endocrinology, Nordsjællands Hospital – Frederikssund, Denmark
| | - Charlotte Larroude
- Department of Cardiology, Nephrology and Endocrinology, Nordsjællands Hospital – Frederikssund, Denmark
- Department of Cardiology, Bispebjerg Hospital, Copenhagen, Denmark
| | - Flemming Dela
- Xlab, Centre for Healthy Ageing, University of Copenhagen, Denmark
| | - Ulrik Pedersen-Bjergaard
- Department of Cardiology, Nephrology and Endocrinology, Nordsjællands Hospital – Hillerød, Denmark
- Department of Clinical Medicine, University of Copenhagen, Denmark
| |
Collapse
|
7
|
Kristensen PL, Pedersen-Bjergaard U, Kjær TW, Olsen NV, Dela F, Holst JJ, Faber J, Tarnow L, Thorsteinsson B. Influence of erythropoietin on cognitive performance during experimental hypoglycemia in patients with type 1 diabetes mellitus: a randomized cross-over trial. PLoS One 2013; 8:e59672. [PMID: 23577069 PMCID: PMC3618268 DOI: 10.1371/journal.pone.0059672] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Accepted: 02/16/2013] [Indexed: 12/23/2022] Open
Abstract
Introduction The incidence of severe hypoglycemia in type 1 diabetes has not decreased over the past decades. New treatment modalities minimizing the risk of hypoglycemic episodes and attenuating hypoglycemic cognitive dysfunction are needed. We studied if treatment with the neuroprotective hormone erythropoietin (EPO) enhances cognitive function during hypoglycemia. Materials and Methods Eleven patients with type 1 diabetes, hypoglycemia unawareness and recurrent severe hypoglycemia completed the study. In a double-blind, randomized, balanced, cross-over study using clamped hypoglycemia they were treated with 40,000 IU of EPO or placebo administered intravenously six days before the two experiments. Cognitive function (primary endpoint), hypoglycemic symptoms, and counter-regulatory hormonal response were recorded. Results Compared with placebo, EPO treatment was associated with a significant reduction in errors in the most complex reaction time task (−4.7 (−8.1 to −1.3), p = 0.01) and a less reaction time prolongation (−66 (−117 to −16) msec, p = 0.02). EPO treatment did not change performance in other measures of cognition. Hypoglycemic symptoms, EEG-changes, and counter-regulatory hormone concentrations did not differ between EPO and placebo treatment. Conclusion In patients with type 1 diabetes and hypoglycemia unawareness, treatment with EPO is associated with a beneficial effect on cognitive function in a complex reaction time task assessing sustained attention/working memory. Hypoglycemic symptoms and hormonal responses were not changed by EPO treatment. Trial Registration ClinicalTrials.gov NCT00615368
Collapse
Affiliation(s)
- Peter Lommer Kristensen
- Endocrinology Section, Department of Cardiology, Nephrology and Endocrinology, Hillerød Hospital, Hillerød, Denmark.
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Færch L, Pedersen-Bjergaard U, Thorsteinsson B. High serum ACE activity predicts severe hypoglycaemia over time in patients with type 1 diabetes. Scandinavian Journal of Clinical and Laboratory Investigation 2011; 71:620-4. [DOI: 10.3109/00365513.2011.604132] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
9
|
Baltatu OC, Campos LA, Bader M. Local renin-angiotensin system and the brain--a continuous quest for knowledge. Peptides 2011; 32:1083-6. [PMID: 21333703 DOI: 10.1016/j.peptides.2011.02.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 02/10/2011] [Indexed: 01/22/2023]
Abstract
The ancient renin-angiotensin system (RAS) was discovered more than a hundred years ago by identifying the rate-limiting enzyme of the system and its relevance to blood pressure regulation. Forty years ago, Detlev Ganten et al. postulated the existence of a tissue RAS. In these forty years, he kept developing the knowledge of these systems either directly or by training or attracting the interest of many researchers. Through the present review, we try to highlight recent advancements that originated from the postulation of local brain RAS. Although a large amount of knowledge accumulated, this system continues to intrigue and stimulate the interest and imagination of many researchers.
Collapse
Affiliation(s)
- Ovidiu C Baltatu
- Center of Biomedical Engineering, University Camilo Castelo Branco, Rod. Presidente Dutra Km 138, SP, 12247-004 São José dos Campos, Brazil
| | | | | |
Collapse
|
10
|
Rice AC, Chiou VL, Zuckoff SB, Shapiro SM. Profile of minocycline neuroprotection in bilirubin-induced auditory system dysfunction. Brain Res 2010; 1368:290-8. [PMID: 20971088 DOI: 10.1016/j.brainres.2010.10.052] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 10/08/2010] [Accepted: 10/14/2010] [Indexed: 12/17/2022]
Abstract
Excessive hyperbilirubinemia in human neonates can cause permanent dysfunction of the auditory system, as assessed with brainstem auditory evoked potentials (BAEPs). Jaundiced Gunn rat pups (jjs) exhibit similar BAEP abnormalities as hyperbilirubinemic neonates. Sulfadimethoxine (sulfa) administration to jjs, which displaces bilirubin from serum albumin into tissues including brain, exacerbates acute toxicity. Minocycline administered prior to sulfa in jjs protects against BAEP abnormalities. This study evaluates the neuroprotective capabilities of minocycline HCl (50 mg/kg) administered 30 or 120 min after sulfa (200 mg/kg) in 16 days old jjs. BAEPs are recorded at 6 or 24 h post-sulfa. Abnormal BAEP waves exhibit increased latency and decreased amplitude. The sulfa/saline treated jjs exhibited a significantly increased interwave interval between waves I and II (I-II IWI) and significantly decreased amplitudes of waves II and III compared to the saline/saline jjs. The minocycline 30 min post-sulfa (sulfa/mino+30) group was not significantly different from the saline/saline control group, indicating neuroprotection. The minocycline 120 min post-sulfa (sulfa/mino+120) group had a significantly decreased amplitude of wave III at both 6 and 24h. These studies indicate that minocycline has a graded neuroprotective effect when administered after acute bilirubin neurotoxicity.
Collapse
Affiliation(s)
- Ann C Rice
- Department of Neurology, Box 980599, Virginia Commonwealth University, Richmond, VA 23298-0599, USA.
| | | | | | | |
Collapse
|