Abstract
Kume Island deep ocean water has a higher specific gravity than tap water or surface ocean water and therefore is expected to produce possible effects by higherwater pressure. In this study we observed the circulation of the rigtht vastus medialis muscle with a laser tissue blood-oxygen moniter and measured blood pressure when subjects were immersed to the xiphoid process in the Kume Island deep ocean water at 34°C. Ten males and 5 females served as subjects. Measurementswere made with the subjects in each of 5 conditions, that is in a standing, sitting, and lying supine on the ground, in standing position in tap water and in the Kume Island deep ocean water. The specific gravity of tap water and Kume Island deep ocean water were 1.00 g/cm3 and 1.03 g/cm3, respectively when measured using a gravimeter (YAGAMI) when measured.
An equilibration period was allowed for each subject, and measurements were taken only after heart rate stabilized (±1) for 30 sec. Blood pressure standing in the Kume Island deep ocean water (SBP; 113.54 ±13.45/DBP; 65.31±12.65 mmHg) was significantly lower than that sitting on the ground (127.23±12.85/81.38±10.44 mmHg). The total hemoglobin (HbT) levels in the vastus medialis muscle at right might reflect the variation in venous return with water pressure or posture. Since no significant difference was found between the blood pressure in lying supine onthe ground and in standing in the Kume Island deep ocean water, and the musculecirculations were also similar, the water pressure was likely to lie within safetrange.
