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Andrew Subudhi

Faculty Publication

Subudhi, A. W., J. -L Fan, O. Evero, N. Bourdillon, B. Kayser, C. G. Julian, A. T. Lovering, and R. C. Roach. "AltitudeOmics: Effect of Ascent and Acclimatization to 5260 m on Regional Cerebral Oxygen Delivery." Experimental Physiology 99, no. 5: 772–781. 2014 DOI: 10.1113/expphysiol.2013.075184

Andy Subudhi, Biology

Article's Abstract

"Cerebral hypoxaemia associated with rapid ascent to high altitude can be life threatening; yet, with proper acclimatization, cerebral function can be maintained well enough for humans to thrive. We investigated adjustments in global and regional cerebral oxygen delivery (inline image) as 21 healthy volunteers rapidly ascended and acclimatized to 5260 m. Ultrasound indices of cerebral blood flow in internal carotid and vertebral arteries were measured at sea level, upon arrival at 5260 m (ALT1; atmospheric pressure 409 mmHg) and after 16 days of acclimatization (ALT16). Cerebral inline image was calculated as the product of arterial oxygen content and flow in each respective artery and summed to estimate global cerebral blood flow. Vascular resistances were calculated as the quotient of mean arterial pressure and respective flows. Global cerebral blood flow increased by ∼70% upon arrival at ALT1 (P < 0.001) and returned to sea-level values at ALT16 as a result of changes in cerebral vascular resistance. A reciprocal pattern in arterial oxygen content maintained global cerebral inline image throughout acclimatization, although inline image to the posterior cerebral circulation was increased by ∼25% at ALT1 (P = 0.032). We conclude that cerebral inline image is well maintained upon acute exposure and acclimatization to hypoxia, particularly in the posterior and inferior regions of the brain associated with vital homeostatic functions. This tight regulation of cerebral inline image was achieved through integrated adjustments in local vascular resistances to alter cerebral perfusion during both acute and chronic exposure to hypoxia." -- from the journal

Posted: 07/08/2014