Acute hyperhomocysteinaemia blunts endothelial dependent and endothelial independent vasodilatation in diabetic patients.
The aim of this study was to investigate the effects of acute, methionine-induced hyperhomocysteinaemia on endothelial function of skin microcirculation in diabetic compared with non-diabetic persons. Endothelial- and non-endothelial-dependent vasodilatation of the skin microcirculation were evaluated in 20 persons with type 2 diabetes (59.95+/-2.36 years old) and 24 age- and gender-matched controls using laser Doppler flowmetry, during fasting and four hours after 0.1 g/kg methionine-induced acute hyperhomocysteinaemia. Methionine loading caused a comparable increase of homocysteine in the two groups. Four hours after induction of acute hyperhomocysteinaemia, endothelial-dependent vasodilatation (acetylcholine effect) was lower in the diabetic patients compared with the controls ([mean+/-SEM] 8.09+/-1.18-fold increase in diabetic patients vs. 11.11+/-1.33-fold increase in controls, p=0.027). The same was observed for the endothelial-independent vasodilatation (sodium-nitroprusside effect, 7.55+/-0.80-fold increase in the diabetic patients vs. 12.19+/-1.26-fold increase in controls, p=0.008). Acute hyperhomocysteinaemia causes a decreased response of both endothelial-dependent and endothelial-independent vasodilatation of the skin microcirculation in diabetic compared with non-diabetic persons. These alterations might contribute to the vascular complications of hyperhomocysteinaemia in diabetes, and especially the microvascular ones.
Chousos
Ilias
I
First Department of Propaedeutic Medicine, University of Athens Medical School, Athens, Greece.
Perrea
Despoina
D
Kyriaki
Despoina
D
Liatis
Stavros
S
Katsilambros
Nicholas
N
Makrilakis
Konstantinos
K
D000109:Acetylcholine / Q000008:administration & dosage; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000503:physiopathology; D003925:Diabetic Angiopathies / Q000209:etiology* / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D005260:Female; D006115:Greece; D006801:Humans; D020138:Hyperhomocysteinemia / Q000150:complications* / Q000503:physiopathology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008715:Methionine / Q000008:administration & dosage; D008833:Microcirculation; D008875:Middle Aged; D009599:Nitroprusside / Q000008:administration & dosage; D012867:Skin / Q000098:blood supply*; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage
D014665:Vasodilator Agents; D009599:Nitroprusside; D008715:Methionine; D000109:Acetylcholine