Local hyperglycemia for 24 hours does not affect endothelium
dependent or independent vasoreactivity in man.
Houben, A. J. H. M., N. C. Schaper, C. H. A. De Haan, F. C. Huvers, D.
W. Slaaf, P. W. De Leeuw, A. C. Nieuwenhuijzen Kruseman.
Department of Internal Medicine, Divisions of Endocrinology and
Nephrology, University Hospital Maastricht; P.O. Box 5800, 6202 AZ
Maastricht; The Netherlands, Department of Biophysics, Cardiovascular
Research Institute Maastricht, University of Limburg; P.O. Box 616,
6200 MD Maastricht; The Netherlands
APStracts 2:0511H, 1995.
Hyperglycemia induces regional hemodynamic changes, as suggested by
animal studies. These hemodynamic changes may play an initiating role
in the pathogenesis of diabetic microangiopathy. The aim of the
present study was to evaluate the effects of acute local
hyperglycemia for 24 hours on basal human forearm muscle and skin
blood flow, and endothelium dependent and independent vasoreactivity.
Local hyperglycemia (approximately 15 mmol/l) was induced by infusion
of 5% glucose into the brachial artery of the nondominant arm. In
control experiments the same individual amount of glucose was infused
intravenously in the dominant arm, to correct for possible systemic
effects of the infused glucose. Vasoreactivity of the forearm
vasculature was evaluated by local infusion of acetylcholine, sodium
nitroprusside, NG-monomethyl-l-arginine (l-NMMA), and noradrenaline
into the brachial artery. Regional hemodynamic measurements were
performed at baseline and after 6, 12, and 24 hours of local
hyperglycemia. Median (with interquartile range) basal forearm
(muscle) blood flow (FBF) was not influenced by the 24-h local
hyperglycemia (FBF-ratio infused/contralateral arm GLUCOSE: 1.32
(1.16-1.64) vs CONTROL: 1.54 (1.34-1.69)). Skin microcirculatory
blood flow (LDF) was neither influenced by the 24-h local
hyperglycemia (LDF-ratio GLUCOSE: 1.00 (0.62-1.56) vs CONTROL: 0.80
(0.58-1.14). In addition, the vasoreactivity of both muscle and skin
(NOT SHOWN) vasculature to acetylcholine (%-change in FBF-ratio
GLUCOSE: 167 (81-263) vs CONTROL : 148 (94-211)%), sodium
nitroprusside (GLUCOSE: 486 (178-586) vs CONTROL: 293 (196-454)%), l
-NMMA (GLUCOSE: -36 (-56 - -22) vs CONTROL: -41 (-51 - -24)%), and
noradrenaline (GLUCOSE: -48 (-72 - -41) vs CONTROL: -66 (-79 - -33)%)
were not affected by the local hyperglycemia as well. Thus, in
contrast to animal studies, our results suggest that a
moderate/severe hyperglycemia does not affect the regulation of basal
blood flow or endothelium dependent or independent vasoreactivity in
man.
Received 22 May 1995; accepted in final form 10 November 1995.
APS Manuscript Number H436-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 November 95