Selected contribution: role of spleen emptying in prolonging apneas in humans

Research output: Contribution to journalArticle

Abstract

This study addressed the interaction between short-term adaptation to apneas with face immersion and erythrocyte release from the spleen. Twenty healthy volunteers, including ten splenectomized subjects, participated. After prone rest, they performed five maximal-duration apneas with face immersion in 10 degrees C water, with 2-min intervals. Cardiorespiratory parameters and venous blood samples were collected. In subjects with spleens, hematocrit and hemoglobin concentration increased by 6.4% and 3.3%, respectively, over the serial apneas and returned to baseline 10 min after the series. A delay of the physiological breaking point of apnea, by 30.5% (17 s), was seen only in this group. These parameters did not change in the splenectomized group. Plasma protein concentration, preapneic alveolar PCO2, inspired lung volume, and diving bradycardia remained unchanged throughout the series in both groups. Serial apneas thus triggered the hematological changes that have been previously observed after long apneic diving shifts; they were rapidly reversed and did not occur in splenectomized subjects. This suggests that splenic contraction occurs in humans as a part of the diving response and may prolong repeated apneas.

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Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Medical and Health Sciences

Keywords

  • Adult, Apnea, Blood Pressure/physiology, Blood Proteins/metabolism, Carbon Dioxide/blood, Face, Female, Heart Rate/physiology, Hematocrit, Hemoglobins/metabolism, Humans, Immersion, Lung Volume Measurements, Male, Regional Blood Flow/physiology, Spleen/ physiology, Splenectomy
Original languageEnglish
Pages (from-to)1623-9; discussion 1606-1623-9; discussion 1606
JournalJournal of Applied Physiology
Volume90
Issue number4
Publication statusPublished - 2001
Publication categoryResearch
Peer-reviewedYes