Oxygen Transport to Tissue XXXI pp 323-328
NIRS Measurement of O2 Dynamics in Contracting Blood and Buffer Perfused Hindlimb Muscle
- Cite this paper as:
- Masuda K., Takakura H., Furuichi Y., Iwase S., Jue T. (2010) NIRS Measurement of O2 Dynamics in Contracting Blood and Buffer Perfused Hindlimb Muscle. In: Takahashi E., Bruley D. (eds) Oxygen Transport to Tissue XXXI. Advances in Experimental Medicine and Biology, vol 662. Springer, Boston, MA
In order to obtain evidence that Mb releases O2 during muscle contraction, we have set up a buffer-perfused hindlimb rat model and applied NIRS to detect the dynamics of tissue deoxygenation during contraction. The NIRS signal was monitored on hindlimb muscle during twitch contractions at 1 Hz, evoked via electrostimulator at different submaximal levels. The hindlimb perfusion was carried out by perfusion of Krebs Bicarbonate buffer. The NIRS still detected a strong signal even under Hb-free contractions. The deoxygenation signal (Δ[deoxy]) was progressively increased at onset of the contraction and reached the plateau under both blood- and buffer-perfused conditions. However, the amplitude of Δ[deoxy] during steady state continued to significantly increase as tension increased. The tension-matched comparison of the Δ[deoxy] level under buffer-perfused and blood perfused conditions indicate that Mb can contribute approximately 50% to the NIRS signal. These results clarify the Mb contribution to the NIRS signal and show a falling intracellular PO2 as workload increases.