Deep diving mammals: Dive behavior and circulatory adjustments contribute to bends avoidance
Deep diving mammals: Dive behavior and circulatory adjustments contribute to bends avoidance
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DOI：
10.1016/j.resp.2005.09.014
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发表时间：
2006-08-01
影响因子：
2.3
通讯作者：
Jones, David R.
中科院分区：
文献类型：
--
作者：
Fahlman, A.;Olszowka, A.;Jones, David R.
建立了一个数学模型，预测屏气潜水过程中血液和组织N-2张力（P-N2）。重复潜水至100 m后，测量的海豚肌肉PN 2（Tursiops truncatus [Ridgway and霍华德，1979，Science，4423，1182-1183]）与模型预测值进行比较。肺萎陷被模拟为100%肺分流，其产生的组织P-N2类似于海豚的报告。另一方面，对于具有潜水反应的动物，预测的肌肉P-N2使心输出量从表面值（20.5至6.81（.）min（-1）），也与在没有肺萎陷的情况下观察到的值一致。事实上，模拟表明，心血管调节和潜水行为对于减少潜水期间的N-2吸收和在到达水面之前立即将组织和血液N-2安全转移回肺部都很重要。特别是，在下降和底部阶段的潜水心动过缓，以及上升率降低和心率增加，使返回水面时的混合静脉P-N2减少了45%。这具有重要的意义，因为惰性气体负荷的小的减少（类似于5%）可以实质上将减压病（DCS）风险减少多达50%（Fahlman等人，2001，J.Appl.Physiol.91，2720-2729）。(c)2005 Elsevier B. V.保留所有权利。
A mathematical model was created that predicted blood and tissue N-2 tension (P-N2) during breath-hold diving. Measured muscle PN2 from the bottlenose dolphin after diving repeatedly to 100 m (Tursiops truncatus [Ridgway and Howard, 1979, Science, 4423, 1182-1183]) was compared with predictions from the model. Lung collapse was modelled as a 100% pulmonary shunt which yielded tissue P-N2 similar to those reported for the dolphin. On the other hand, predicted muscle P-N2 for an animal with a dive response, reducing cardiac output by 66% from surface values (20.5 to 6.81(.)min(-1)), also agreed well with observed values in the absence of lung collapse. In fact, modelling indicated that both cardiovascular adjustments and dive behaviour are important in reducing N-2 uptake during diving and enhancing safe transfer of tissue and blood N-2 back to the lung immediately before coming to the surface. In particular, diving bradycardia during the descent and bottom phase together with a reduced ascent rate and increase in heart rate reduced mixed venous P-N2 upon return to the surface by as much as 45%. This has important implications as small reductions in inert gas load (similar to 5%) can substantially reduce decompression sickness (DCS) risk by as much as 50% (Fahlman et al., 2001, J. Appl. Physiol. 91, 2720-2729). (c) 2005 Elsevier B.V. All rights reserved.