2007, Piran, Slovenia

Environmental Ergonomics XII
Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007
term altitude exposure was related to tonic spleen contraction (Cook and Alafi 1956)
but little scientific interest has been shown to the possible role of the spleen in altitude
acclimatization in humans. It is conceivable that the human spleen, in hypoxic
environments, responds to eupnea in a similar manner as during apnea in normoxic
environments – that is, by a contraction leading to an increased number of circulating
erythrocytes and resultant oxygen carrying capacity. Further apneic interventions on
an “empty” spleen may therefore not result in any further increases in Hb. Apneic
duration increase across the series would also be reduced, as was the case at the
highest altitude, where no increases within the 3-apnea series were noted. Conversely,
post-acclimatization apneic responses may be augmented due to the spleen again
containing an ejectable erythrocyte volume, with subsequently increased apneic
duration and a reduction in apneic arterial oxygen desaturation. Further studies on
larger groups in controlled environments will be needed to reveal the relative role of
the spleen in acclimatization to altitude in humans.
REFERENCES
Cook, S.F. and Alafi M.H. 1956. Role of the spleen in acclimatization to hypoxia. Am
J Physiol 186(2): 369-372, 1956.
Hurford, W.E., S.K. Hong, Y.S. Park, D.W. Ahn, K. Shiraki, M. Mohri, W.M. Zapol.
1990. Splenic contraction during breath-hold diving in the Korean Ama. J Appl
Physiol 69(3): 932-936.
Richardson, M., Haughey, H., de Bruijn, R., Andersson, J., Schagatay, E. 2003.
Hematological Response pattern associated with maximal-duration Apnea series
in untrained subjects. Abstract, European Undersea and Baromedical Society
Annual Meeting, Copenhagen.
Richardson, M., de Bruijn, R., Schagatay, E., 2005. Hypoxia - a trigger for spleen
contraction? Abstract, International Conference on Diving and Hyperbaric
Medicine, Barcelona.
Schagatay, E., Andersson, J. P. A., Hallén, M., Pålsson, B., 2001. Selected
Contribution: Role of spleen emptying in prolonging apneas in humans. J Appl
Physiol 90(4): 1623-1629.
Schagatay, E., Haughey, H., Reimers, J. 2005. Speed of spleen volume changes
evoked by serial apneas. Eur J Appl Physiol 93(4): 447-452.
92