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Impaired skin microcirculation in paediatric patients with type 1 diabetes mellitus. Cardiovasc Diabetol 2013; 12:115. [PMID: 23937662 PMCID: PMC3751195 DOI: 10.1186/1475-2840-12-115] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 08/12/2013] [Indexed: 11/11/2022] Open
Abstract
Aims/hypothesis We used Laser Doppler Fluximetry (LDF) to define "normal" endothelial function in a large cohort of healthy children and adolescents and to evaluate skin microcirculation in paediatric patients with type 1 diabetes mellitus. Methods LDF was performed in 102 healthy children (12.8 ± 3.3 years of age; 48 male) and 68 patients (12.9 ± 3.3 years of age; 33 male). Duration of disease was 5.0 ± 3.97 years. Each participant sequentially underwent three stimulation protocols (localized thermal hyperaemia with localized warming to maximum 40°C, iontophoretic delivery of pilocarpine hydrochloride (PCH) and sodium nitroprusside (SNP)). The maximum relative increase in skin blood flow and the total relative response, i.e. the area under the curve (AUC) to each stimulus (AUCheat, AUCPCH, AUCSNP) was determined. In addition, the area of a right-angled triangle summarizing the time to and the amplitude of the first peak, which represents the axon reflex mediated neurogenic vasodilation (ARR) was calculated. Results In healthy controls, AUCheat, AUCPCH, AUCSNP, and ARR turned out to be independent of sex, age, and anthropometric values. Per parameter the 10th percentile generated from data of healthy controls was used as the lower threshold to define normal endothelial function. Diabetic patients showed significantly reduced vasodilatative response to either physical or pharmacological stimulation with SNP, whereas the response to PCH was comparable in both cohorts. In patients compared to controls i) a significantly higher frequency of impaired vasodilatation in response to heat and SNP was noted and ii) vascular response was classified as pathological in more than one of the parameters with significantly higher frequency. Conclusions/interpretation Skin microvascular endothelial dysfunction is already present in about 25% of paediatric type 1 diabetic patients suffering from type 1 diabetes for at least one year. Future studies are needed to assess the predictive value of endothelial dysfunction in the development of long-term (cardio)vascular comorbidity in these patients.
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Giebink AW, Vogel PA, Medawala W, Spence DM. C-peptide-stimulated nitric oxide production in a cultured pulmonary artery endothelium is erythrocyte mediated and requires Zn(2+). Diabetes Metab Res Rev 2013; 29:44-52. [PMID: 23007928 DOI: 10.1002/dmrr.2359] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 08/23/2012] [Indexed: 12/13/2022]
Abstract
BACKGROUND C-peptide has been shown to stimulate the production of nitric oxide (NO) in aortic endothelial cells via activation of endothelial nitric oxide synthase (eNOS) through an increased calcium influx. Here, results obtained using cultured bovine pulmonary artery endothelial cells (bPAECs) suggest that C-peptide does not induce eNOS activation directly in cultured pulmonary artery endothelium. However, C-peptide has been shown to stimulate the release of ATP from erythrocytes, a well-documented stimulus of eNOS activity in the pulmonary endothelium. Therefore, studies were performed to examine if C-peptide can indirectly stimulate NO production in a cultured pulmonary endothelium that is erythrocyte mediated. METHODS NO production and free intracellular calcium changes were monitored in immobilized bPAECs using specific intracellular fluorescent probes after stimulation with adenosine triphosphate (ATP), calcium ionophore A23187, or C-peptide. A microfluidic device enabled immobilized bPAECs to interact with flowing erythrocytes in the presence and absence of C-peptide to determine the role of the erythrocyte in C-peptide-stimulated NO production in cultured bPAECs. RESULTS ATP and the calcium ionophore stimulate significant increases in both intracellular NO production and influx of free calcium in cultured bPAECs. In contrast, C-peptide, ranging from physiological to above physiological concentrations, was unable to stimulate NO production or calcium influx in the bPAECs. However, when erythrocytes were pre-incubated with a mixture containing physiological concentrations of C-peptide with Zn(2+) and haemodynamically pumped beneath bPAECs cultured on a microfluidic device, an 88.6 ± 7.5% increase in endothelial NO production was observed. CONCLUSIONS C-peptide does not affect NO production in bPAECs directly but can impact NO production through an erythrocyte-mediated mechanism. Furthermore, in the absence of Zn(2+), C-peptide does not stimulate this NO production directly or indirectly. These results suggest that C-peptide, in the presence of Zn(2+), may be a determinant in purinergic receptor signalling via its ability to stimulate the release of ATP from erythrocytes.
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Affiliation(s)
- Adam W Giebink
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
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Mahé G, Humeau-Heurtier A, Durand S, Leftheriotis G, Abraham P. Assessment of Skin Microvascular Function and Dysfunction With Laser Speckle Contrast Imaging. Circ Cardiovasc Imaging 2012; 5:155-63. [DOI: 10.1161/circimaging.111.970418] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Guillaume Mahé
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
| | - Anne Humeau-Heurtier
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
| | - Sylvain Durand
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
| | - Georges Leftheriotis
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
| | - Pierre Abraham
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
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Forst T, Hach T, Kunt T, Weber MM, Pfützner A. Molecular effects of C-Peptide in microvascular blood flow regulation. Rev Diabet Stud 2009; 6:159-67. [PMID: 20039005 DOI: 10.1900/rds.2009.6.159] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
C-Peptide is produced in beta-cells in the pancreas, and secreted into the blood stream in equimolar amounts with insulin. For a long time, C-peptide was considered as an important component in the biosynthesis of insulin, but otherwise believed to possess minimal biological activity. In the recent years, numerous studies demonstrated that lacking C-peptide in type 1 diabetic patients might exert an important role in the development of microvascular complications such as nephropathy or neuropathy. There is increasing evidence that the biological effects of C-peptide are, at least in part, mediated through the modulation of endothelial function and microvascular blood flow. In several tissues, an increase in microvascular and nutritional blood flow could be observed during substitution of physiological amounts of C-peptide. Recent studies confirmed that C-peptide stimulates endothelial NO release by the activation of Ca2+ calmodulin-regulated endothelial NO synthase. A restoration of Na+/K+-ATPase activity during C-peptide supplementation could be observed in erythrocytes and renal tubular cells. The improvement of erythrocyte Na+/K+-ATPase is associated with an increase in erythrocyte deformability, and improved rheological properties. In this article, we consider the role of C-peptide in the context of endothelial function and microvascular blood flow as pathophysiologic components in the development of microvascular complications in patients with diabetes mellitus and loss of beta-cell function.
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Affiliation(s)
- Thomas Forst
- Institute for Clinical Research and Development, Parcusstr. 8, 55116 Mainz, Germany
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