Spleen emptying does not correlate with faster oxygen kinetics during a step-transition supine cycling.

Abstract

This manuscript quantified spleen volume changes and examined the relationship between those changes and oxygen uptake kinetics during supine cycling. Ten volunteers (age= 22± 3), completed 3 step transitions from 20W to their power output at 90% gas exchange threshold. Ultrasonic measurements of the spleen were performed each minute. The largest spleen volume reduction was 105mL (p= 0.001). No associations existed between i) spleen volumes at rest; and ii) spleen volume changes (%) and tau pulmonary oxygen uptake (τV̇O2p). Larger resting spleen volume and greater emptying do not correlate with a faster τV̇O2p. Novelty: Greater splenic contractions do not augment τV̇O2p, irrespective of spleen emptying and subsequent erythrocyte release.