Muscle blood flow response to mental stress and adrenaline infusion in man: microdialysis ethanol technique compared to 133Xe clearance and venous occlusion plethysmography

作者：Widegren U; Hickner R C; Jorfeldt L; Henriksson J^*

来源：Clinical Physiology and Functional Imaging, 2010, 30(2): 152-161.

DOI：10.1111/j.1475-097X.2009.00919.x

• 133Xe clearance
• adrenaline
• blood flow
• mental stress
• microdialysis
• skeletal muscle
• venous occlusion plethysmography

P>Background and aim:
Adrenaline, administered locally by microdialysis in skeletal muscle, causes vasoconstriction around the microdialysis catheter. This is contrary to the vasodilation that normally occurs when adrenaline is infused intravenously or intra-arterially. The hypothesis was tested that vasoconstriction, measured by microdialysis, would not occur with two interventions causing increased plasma levels of adrenaline, mental stress and intravenous adrenaline infusion (0 center dot 1 nmol kg-1 min-1).
Methods:
Twenty-four men (27 +/- 1 center dot 6 years) underwent these interventions. Blood flow was determined by the microdialysis ethanol technique and 133Xe clearance (gastrocnemius muscle, medial head) and by venous occlusion plethysmography (calf).
Results:
The ethanol outflow/inflow ratio, which is inversely related to blood flow, decreased to 92 center dot 0 +/- 3 center dot 4% of basal, P = 0 center dot 014 (mean +/- SEM, n = 16) during the mental stress test, but increased to 108 center dot 3 +/- 2 center dot 2% of basal, P = 0 center dot 001 (n = 16) during the adrenaline infusion. The latter increase was abolished when adrenaline was infused during alpha-receptor blockade by phentolamine. On the contrary, by 133Xe clearance and venous occlusion plethysmography, blood flow increased during both interventions; 2 center dot 0-1 center dot 7-fold (mental stress) and 1 center dot 3-1 center dot 4-fold (adrenaline infusion), respectively, P < 0 center dot 05.
Conclusion:
Adrenaline causes vasoconstriction in skeletal muscle when blood flow is measured with the microdialysis ethanol technique, irrespective of the mode of administration. The discrepant blood flow result obtained with the microdialysis ethanol technique might, at least partly, be explained by differential diffusion properties of ethanol and 133Xe. An additional or alternative explanation might be that an inserted microdialysis catheter shifts the balance of vasoconstrictor and vasodilator effects of adrenaline in skeletal muscle.

• 出版日期2010-3