Splenic contraction during breath-hold diving in the Korean ama

Abstract

Major increases of hemoglobin concentration and hematocrit, possibly secondary to splenic contraction, have been noted during diving in the Weddell seal. We sought to learn whether this component of the diving response could be present in professional human breath-hold divers. Splenic size was measured ultrasonically before and after repetitive breath-hold dives to approximately 6-m depth in ten Korean ama (diving women) and in three Japanese male divers who did not routinely practice breath-hold diving. Venous hemoglobin concentration and hematocrit were measured in nine of the ama and all Japanese divers. In the ama, splenic length and width were reduced after diving (P = 0.0007 and 0.0005, respectively) and calculated splenic volume decreased 19.5 +/- 8.7% (mean +/- SD, P = 0.0002). Hemoglobin concentration and hematocrit increased 9.5 +/- 5.9% (P = 0.0009) and 10.5 +/- 4% (P = 0.0001), respectively. In Japanese male divers, splenic size and hematocrit were unaffected by repetitive breath-hold diving and hemoglobin concentration increased only slightly over baseline (3.0 +/- 0.6%, P = 0.0198). Splenic contraction and increased hematocrit occur during breath-hold diving in the Korean ama.

Exercise induced hemoconcentration following spleen contraction in subjects with COPD

“…The latter finding suggests that this spleen function may be essential for these individuals during hypoxic challenges similar to that found in healthy subjects during maximal exercise [23], high altitude simulation [13,14] or apnea [4,5,7]. In …”

“…prolonging apnea duration [4]. Splenic contribution of Hb to the circulating blood volume has also been observed in healthy subjects during exercise [10][11][12] and more recently during altitude simulation by normobaric hypoxia [13,14].…”

“…diving seals, spleen contraction may prolong aerobic dive duration [2,3]. In healthy human subjects, spleen contraction and circulating hemoglobin (Hb) increase have also been observed during apnea [4][5][6][7]. Interestingly, apnea in splenectomized subjects was found not to induce a Hb increase [5], and neonates with asplenia showed impaired transient elevation of blood Hb in response to acute hypoxia [8].…”

The human diving response, its function, and its control

“…The concept of splenic contraction has recently been described as a property of the human diving response (Hurford et al, 1990;Schagatay et al, 2001;Espersen et al, 2002;Bakovic et al, 2003) and, as seen in intermittent hypoxia studies, may play an O 2 -conserving role (Kuwahira et al, 1999(Kuwahira et al, , 2000. The spleen serves as a dynamic erythrocyte blood cell reservoir that contracts and releases significant volume of erythrocytes during increased activity (Stewart et al, 2003), diving (Espersen et al, 2002), or in response to severe hypoxia (Hoka et al 1989).…”

“…Their arterial blood pressure is not maintained and can dramatically increase to values as high as 280/200 mmHg (systolic/diastolic) (Ferrigno et al, 1997). Recent evidence suggests that an active contraction of the spleen is also a characteristic of the human diving response (Hurford et al, 1990). This concept of splenic contraction is based on hematological observation (Schagatay, et al 2001), radionuclide measurements (Espersen, et al 2002), and ultrasonic measurements of spleen volume (Bakovic et al, 2003).…”