Effect of hypoxia on arterial and venous blood levels of oxygen, carbon dioxide, hydrogen ions and lactate during incremental forearm exercise

Abstract

The purpose of the present study was to investigate whether, in humans, hypoxia results in an elevated lactate production from exercising skeletal muscle. Under conditions of both hypoxia [inspired oxygen fraction (F1O2): 11.10%] and normoxia (F1O2: 20.94%), incremental exercise of a forearm was performed. The exercise intensity was increased every minute by 1.6 kg.m.min-1 until exhaustion. During the incremental exercise the partial pressure of oxygen (PO2) and carbon dioxide (PCO2), oxygen saturation (SO2), pH and lactate concentration [HLa] of five subjects, were measured repeatedly in blood from the brachial artery and deep veins from muscles in the forearm of both the active and inactive sides. The hypoxia (arterial SO2 approximately 70%) resulted in (1) the difference in [HLa] in venous blood from active muscle (values during exercise-resting value) often being more than twice that for normoxia, (2) a significantly greater difference in venous-arterial (v-a) [HLa] for the exercising muscle compared to normoxia, and (3) a difference in v-a [HLa] for non-exercising muscle that was slightly negative during normoxia and more so with hypoxia. These studies suggest that lower O2 availability to the exercising muscle results in increased lactate production.

Haemodynamic and metabolic responses of the lower limb after high intensity exercise in humans

“…7). As expected, the arterialized lactate levels results were higher by 1-2 mmol 1Iat the peak of the response (Yoshida, Udo, Chida, Ichioka & Makiguchi, 1989).…”

Imaging of hemoglobin oxygen saturation variations in single vessels in vivo using photoacoustic microscopy

“…The imaged changes of SO 2 in the arterioles matched the oximeter readings and other published data. [23][24][25] Based on anatomical observation, the imaged blood vessels were located beneath the dermis. The wavelengthdependent optical attenuation in the dermal layer must be considered in imaging SO 2 .…”

Functional Photoacoustic Microscopy

“…readings and other published data. [88][89][90] Although the same compensation was applied to all the three physiological states, the systematic change of SO 2 itself does affect optical attenuation in skin. Thus, such compensation should be adjusted for different physiological states accordingly to achieve a more precise quantitative measurement.…”