Hoar P F, Raymond L W, Langworthy H C, Johnsonbaugh R E, Sode J
J Appl Physiol. 1976 Apr;40(4):605-10. doi: 10.1152/jappl.1976.40.4.605.
Fourteen scuba divers in swim trunks did ergometer work while breathing air at 3 m in 25.5 degrees C water. They were stressed by work and cold. Exercise produced increases in heart rate, minute ventilation (VE), oxygen consumption (VO2), and catecholamine excretion. Cold lowered rectal temperature (Tre) despite exercise, and contributed to the increase in VO2 and catecholamine excretion. Immersion, cutaneous vasoconstriction, work, and scuba breathing contributed to a brisk diuresis, probably by centralizing blood volume and thus stimulating central vascular volume receptors. Similar exercise in 25.5 degrees C water, breathing helium tri-mix (gas density less than air), produced higher VE but lower VO2 when compared to air breathing. Tri-mix scuba breathing resulted in a smaller diuresis, perhaps because its lower density leads to lesser atrial distension during work. The fall in Tre during work in 25.5 degrees C water was identical whether air or helium tri-mix was respired, since helium does not accentuate respiratory convective heat transfer.
14名穿着泳裤的潜水员在25.5摄氏度的水中3米深处呼吸空气时进行了测力计运动。他们因运动和寒冷而承受压力。运动使心率、分钟通气量（VE）、耗氧量（VO2）和儿茶酚胺排泄量增加。尽管运动，寒冷仍降低了直肠温度（Tre），并导致VO2和儿茶酚胺排泄量增加。浸入水中、皮肤血管收缩、运动和水肺呼吸可能通过集中血容量从而刺激中枢血管容量感受器，导致尿量增加。与呼吸空气相比，在25.5摄氏度的水中进行类似运动，呼吸氦三混合气（气体密度小于空气）时会产生更高的VE，但VO2更低。氦三混合气潜水呼吸导致的尿量较少，可能是因为其较低的密度在运动期间导致心房扩张较小。在25.5摄氏度的水中运动时，无论呼吸空气还是氦三混合气，Tre的下降都是相同的，因为氦不会加剧呼吸对流热传递。
