scholarly journals Increased forearm blood flow in longstanding Type 1 diabetic patients without microvascular complications

2007 ◽  
Vol 24 (2) ◽  
pp. 208-210 ◽  
Author(s):  
P. J. van Gurp ◽  
J. W. M. Lenders ◽  
C. J. Tack
2003 ◽  
Vol 285 (4) ◽  
pp. E864-E870 ◽  
Author(s):  
Bo-Lennart Johansson ◽  
John Wahren ◽  
John Pernow

Proinsulin C-peptide has been shown to increase muscle blood flow in type 1 diabetic patients. The underlying mechanism is not fully understood. The aim of this study was to evaluate if the vasodilator effect of C-peptide is mediated by nitric oxide (NO). Eleven type 1 diabetic patients were studied two times and randomized to administration of intravenous and intra-arterial infusion of C-peptide or saline. Forearm blood flow (FBF) was measured by venous occlusion plethysmography during infusion of C-peptide or saline before, during, and after NO synthase (NOS) blockade. Endothelium-dependent and -independent vasodilatation was evaluated by administration of acetylcholine and sodium nitroprusside, respectively. FBF increased by 35% during intravenous C-peptide ( P < 0.01) but not during saline infusion (–2%, not significant). NOS blockade resulted in a more pronounced reduction in FBF during intravenous C-peptide than during saline infusion (–41 vs. –26%, P < 0.05). Intra-arterial C-peptide failed to increase FBF during NOS blockade. However, when C-peptide was given after the recovery from NOS blockade, FBF rose by 30% ( P < 0.001). The vasodilator effects of acetylcholine and nitroprusside were not influenced by C-peptide. It is concluded that the stimulatory effect of C-peptide on FBF in type 1 diabetic patients is mediated via the NO system and that C-peptide increases basal endothelial NO levels.


1987 ◽  
Vol 72 (1) ◽  
pp. 123-130 ◽  
Author(s):  
J. Kastrup ◽  
T. Nørgaard ◽  
H.-H. Parving ◽  
N. A. Lassen

1. The distensibility of the resistance vessels of the skin at the dorsum of the foot was determined in 11 long-term type 1 (insulin-dependent) diabetic patients with nephropathy and retinopathy, nine short-term type 1 diabetic patients without clinical microangiopathy and in nine healthy non-diabetic subjects. 2. Blood flow was measured by the local 133Xexenon washout technique in a vascular bed locally paralysed by the injection of histamine. Blood flow was measured before, during and after a 40 mmHg increase of the vascular transmural pressure, induced by head-up tilt. 3. The mean increase in blood flow during headup tilt was only 24% in diabetic subjects with and 48% in diabetic patients without clinical microangiopathy, compared with 79% in normal non-diabetic subjects (P < 0.0005 and P < 0.05, respectively). 4. An inverse correlation between microvascular distensibility and degree of hyalinosis of the terminal arterioles in biopsies from the skin was demonstrated (r = − 0.57, P < 0.001). 5. Our results suggest that terminal arteriolar hyalinosis reduces the microvascular distensibility and probably increases the minimal vascular resistance, thereby impeding hyperaemic responses.


Diabetes Care ◽  
2005 ◽  
Vol 28 (7) ◽  
pp. 1649-1655 ◽  
Author(s):  
C. E.M. De Block ◽  
I. H. De Leeuw ◽  
L. F. Van Gaal

Diabetologia ◽  
2005 ◽  
Vol 48 (9) ◽  
pp. 1911-1918 ◽  
Author(s):  
J. Frystyk ◽  
L. Tarnow ◽  
T. Krarup Hansen ◽  
H.-H. Parving ◽  
A. Flyvbjerg

2005 ◽  
Vol 21 (6) ◽  
pp. 525-532 ◽  
Author(s):  
Nicola Eberl ◽  
Wolfgang Piehlmeier ◽  
Stefan Dachauer ◽  
August König ◽  
Walter Land ◽  
...  

2016 ◽  
Author(s):  
Edita Prakapiene ◽  
Aiste Kondrotiene ◽  
Egle Kreivaitiene ◽  
Raminta Miezyte ◽  
Karolina Bauraite ◽  
...  

Diabetes Care ◽  
2010 ◽  
Vol 33 (9) ◽  
pp. 2038-2042 ◽  
Author(s):  
B. Pemp ◽  
E. Polska ◽  
G. Garhofer ◽  
M. Bayerle-Eder ◽  
A. Kautzky-Willer ◽  
...  

2004 ◽  
Vol 5 (1) ◽  
pp. 51-64 ◽  
Author(s):  
T. Forst ◽  
T. Kunt

Beside functional and structural changes in vascular biology, alterations in the rheologic properties of blood cells mainly determines to an impaired microvascular blood flow in patients suffering from diabetes mellitus. Recent investigations provide increasing evidence that impaired C-peptide secretion in type 1 diabetic patients might contribute to the development of microvascular complications. C-peptide has been shown to stimulate endothelial NO secretion by activation of theCa2+calmodolin regulated enzyme eNOS. NO himself has the potency to increase cGMP levels in smooth muscle cells and to activateNa+K+ATPase activity and therefore evolves numerous effects in microvascular regulation. In type 1 diabetic patients, supplementation of C-peptide was shown to improve endothelium dependent vasodilatation in an NO-dependent pathway in different vascular compartments. In addition, it could be shown that C-peptide administration in type 1 diabetic patients, results in a redistribution of skin blood flow by increasing nutritive capillary blood flow in favour to subpapillary blood flow. ImpairedNa+K+ATPase in another feature of diabetes mellitus in many cell types and is believed to be a pivotal regulator of various cell functions. C-peptide supplementation has been shown to restoreNa+K+ATPase activity in different cell types during in vitro and in vivo investigations. In type 1 diabetic patients, C-peptide supplementation was shown to increase erythrocyteNa+K+ATPase activity by about 100%. There was found a linear relationship between plasma C-peptide levels and erythrocyteNa+K+ATPase activity. In small capillaries, microvascular blood flow is increasingly determined by the rheologic properties of erythrocytes. Using laser-diffractoscopie a huge improvement in erythrocyte deformability could be observed after C-peptide administration in erythrocytes of type 1 diabetic patients. Inhibition of theNa+K+ATPase by Obain completely abolished the effect of C-peptide on erythrocyte deformability. In conclusion, C-peptide improves microvascular function and blood flow in type 1 diabetic patients by interfering with vascular and rheological components of microvascular blood flow.


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