Testing of cerebral endothelium function with L-arginine after stroke

• Published in: International angiology Vol. 21; no. 3; pp. 256 - 259
• Main Authors: ZVAN, B, ZALETEL, M, POGACNIK, T, KIAUTA, T
• Format: Journal Article
• Language: English
• Published: Torino Minerva Medica 01.09.2002; Edizioni Minerva Medica
• Subjects: Aged; Arginine; Biological and medical sciences; Blood Flow Velocity - drug effects; Blood Flow Velocity - physiology; Brain Ischemia - complications; Brain Ischemia - physiopathology; Cerebrovascular Circulation - drug effects; Cerebrovascular Circulation - physiology; Endothelium, Vascular - drug effects; Endothelium, Vascular - physiopathology; Female; Humans; Infarction, Middle Cerebral Artery - etiology; Infarction, Middle Cerebral Artery - physiopathology; Male; Medical sciences; Middle Aged; Middle Cerebral Artery - drug effects; Middle Cerebral Artery - physiopathology; Neurology; Reperfusion Injury - diagnosis; Reperfusion Injury - etiology; Reperfusion Injury - physiopathology; Reproducibility of Results; Time Factors; Vascular diseases and vascular malformations of the nervous system; Vascular Resistance - drug effects; Vascular Resistance - physiology; Sonography; Doppler ultrasound study; Human; Nervous system diseases; Stroke; Middle cerebral artery; Carbon dioxide; Cardiovascular disease; Early stage; Reperfusion injury; Cerebral disorder; Endothelium; Vascular disease; Reperfusion; Endothelium, vascular; Arginine; Ischemia; Aminoacid; Nitric oxide; Central nervous system disease; Cerebrovascular accident; Arterial pressure; Cerebrovascular disease; Monitoring
• ISSN: 0392-9590; 1827-1839

Endothelium-dependent vasodilatation could be impaired during hypoperfusion. L-arginine (L-A), a precursor of nitric oxide, is able to elicit endothelium-dependent vasodilatation. To determine cerebral vascular endothelial function in the early stages after ischemic stroke, we studied cerebrovascular reactivity to L-A with transcranial Doppler (TCD). The study group consisted of 15 patients with the middle cerebral artery syndrome, aged 57.6+/-9.8 years. They were investigated on days 7 to 10 after ischemic stroke. The control group consisted of 15 healthy volunteers, aged 58+/-10.7 years. All subjects received an intravenous infusion of L-A over 20 min at a rate of 1.5 g/min. The mean arterial velocity (vm) was measured in both middle cerebral arteries by using a bitemporal monitoring system (Multi-Dop X4, DWL). At the same time, the mean arterial pressure (MAP) and heart rate (HR) were measured by Finapres and ECG. The end-tidal CO2 (Et-Co2) was monitored by capnograph. The Vm over 5-min intervals at rest and during the infusion of L-A was determined by using the DWL TCD8 software. The Vm significantly increased in both hemispheres of both groups (p=0.00). Vm differences between rest and L-A stimulation were lower in the ischemic hemispheres compared to the healthy ones (p=0.00), but did not differ between the ischemic hemispheres and hemispheres of the healthy group (p>0.05). MAP, HR and Et-Co2 did not change during the infusion (p>0.05). Cerebrovascular reactivity to L-A is impaired in patients with recent stroke. The amino acid could thus be useful in testing endothelium function both in healthy persons and in stroke patients since endothelium dysfunction seems to be an important factor in reperfusion injury.