Transcerebral exchange kinetics of nitrite and calcitonin gene-related peptide in acute mountain sickness: evidence against trigeminovascular activation?
Research output: Contribution to journal › Journal article › Research › peer-review
BACKGROUND AND PURPOSE: High-altitude headache is the primary symptom associated with acute mountain sickness, which may be caused by nitric oxide-mediated activation of the trigeminovascular system. Therefore, the present study examined the effects of inspiratory hypoxia on the transcerebral exchange kinetics of the vasoactive molecules, nitrite (NO(2)(*)), and calcitonin gene-related peptide (CGRP). METHODS: Ten males were examined in normoxia and after 9-hour exposure to hypoxia (12.9% O(2)). Global cerebral blood flow was measured by the Kety-Schmidt technique with paired samples obtained from the radial artery and jugular venous bulb. Plasma CGRP and NO(2)(*) were analyzed via radioimmunoassay and ozone-based chemiluminescence. Net cerebral exchange was calculated by the Fick principle and acute mountain sickness/headache scores assessed via clinically validated questionnaires. RESULTS: Hypoxia increased cerebral blood flow with a corresponding increase in acute mountain sickness and headache scores (P<0.05 vs normoxia). Hypoxia blunted the cerebral uptake of NO(2)(*), whereas CGRP exchange remained unaltered. No relationships were observed between the change (hypoxia-normoxia) in cerebral NO(2)(*) or CGRP exchange and acute mountain sickness/headache scores (P>0.05). CONCLUSIONS: These findings argue against sustained trigeminovascular system activation as a significant event in acute mountain sickness.
Original language | English |
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Journal | Stroke |
Volume | 40 |
Issue number | 6 |
Pages (from-to) | 2205-8 |
Number of pages | 3 |
ISSN | 0039-2499 |
DOIs | |
Publication status | Published - 2009 |
Bibliographical note
Keywords: Adult; Altitude Sickness; Anoxia; Brain Chemistry; Calcitonin Gene-Related Peptide; Cerebrovascular Circulation; Headache; Humans; Kinetics; Luminescence; Male; Nitric Oxide; Questionnaires; Trigeminal Nerve
ID: 20008997