Naslov
No differences in splenic emptying during on- transient supine cycling between aerobically trained and untrained participants

Autori
Zubac, Damir ; Obad, Ante ; Šupe-Domić, Daniela ; Bošnjak, Ana ; Zec, Mirela ; Ivančev, Vladimir ; Valić, Zoran

Izvornik
European Journal of Applied Physiology (1439-6319) 122 (2022), 4; 903-917

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Blood O2 carrying capacity · ΔHHb kinetics · Aerobic exercise · Muscle bioenergetics

Sažetak
Purpose: The role of splenic emptying in O2 transport during aerobic exercise still remains a matter of debate. Our study compared the differences in spleen volume changes between aerobically trained and untrained individuals during step-transition supine cycling exercise at moderate-intensity. We also examined the relationship between spleen volume changes, erythrocyte release, and O2 uptake parameters. Methods: Fourteen healthy men completed all study procedures, including a detailed medical examination, supine maximal O2 uptake ([Formula: see text] max.) test, and three step-transitions from 20 W to a moderate-intensity power output, equivalent to [Formula: see text] uptake at 90% gas exchange threshold. During these step- transitions pulmonary [Formula: see text], near- infrared spectroscopy of the vastus lateralis, and cardiovascular responses were continuously measured. In parallel, minute-by-minute ultrasonic measurements of the spleen were performed. Blood samples were taken before and immediately after step-transition cycling. Results: On average, [Formula: see text] max. was 10 mL kg min-1 (p = 0.001) higher in trained compared to their aerobically untrained peers. In response to supine step-transition cycling, the splenic volume was significantly reduced, and the largest reduction (~ 106 to 115 mL, ~ 38%, p = 0.001) was similar in both aerobically trained and untrained individuals. Erythrocyte concentration and platelet count transiently increased after exercise cessation, with no differences observed between groups. However, the vastus lateralis deoxygenation amplitude was 30% (p = 0.001) greater in trained compared to untrained individuals. No associations existed between: (i) spleen volumes at rest (ii) spleen volume changes (%), (iii) resting hematocrit and oxygen uptake parameters. Conclusion: Greater splenic emptying and subsequent erythrocyte release do not lead to a slower [Formula: see text], regardless of individual [Formula: see text] max. readings.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA