Gutierrez Danielle B, Fahlman Andreas, Gardner Manuela, Kleinhenz Danielle, Piscitelli Marina, Raverty Stephen, Haulena Martin, Zimba Paul V
Department of Life Sciences, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA.
Comparative Physiology Laboratory, Department of Life Sciences, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA.
Respir Physiol Neurobiol. 2015 Jun;211:29-36. doi: 10.1016/j.resp.2015.02.004. Epub 2015 Mar 23.
Marine mammals are repeatedly exposed to elevated extra-thoracic pressure and alveolar collapse during diving and readily experience alveolar expansion upon inhalation - a unique capability as compared to terrestrial mammals. How marine mammal lungs overcome the challenges of frequent alveolar collapse and recruitment remains unknown. Recent studies indicate that pinniped lung surfactant has more anti-adhesive components compared to terrestrial mammals, which would aid in alveolar opening. However, pulmonary surfactant composition has not yet been investigated in odontocetes, whose physiology and diving behavior differ from pinnipeds. The aim of this study was to investigate the phosphatidylcholine (PC) composition of lung surfactants from various marine mammals and compare these to a terrestrial mammal. We found an increase in anti-adhesive PC species in harp seal (Pagophilus groenlandicus) and California sea lion (Zalophus californianus) compared to dog (Canus lupus familiaris), as well as an increase in the fluidizing PCs 16:0/14:0 and 16:0/16:1 in pinnipeds compared to odontocetes. The harbor porpoise (a representative of the odontocetes) did not have higher levels of fluidizing PCs compared to dog. Our preliminary results support previous findings that pinnipeds may have adapted unique surfactant compositions that allow them to dive at high pressures for extended periods without adverse effects. Future studies will need to investigate the differences in other surfactant components to fully assess the surfactant composition in odontocetes.
海洋哺乳动物在潜水过程中反复暴露于升高的胸外压力和肺泡塌陷，并且在吸气时很容易经历肺泡扩张——这是与陆生哺乳动物相比的独特能力。海洋哺乳动物的肺部如何克服频繁肺泡塌陷和复张的挑战仍然未知。最近的研究表明，与陆生哺乳动物相比，鳍足类动物的肺表面活性剂具有更多的抗黏附成分，这有助于肺泡开放。然而，尚未对齿鲸类动物的肺表面活性剂成分进行研究，其生理和潜水行为与鳍足类动物不同。本研究的目的是调查各种海洋哺乳动物肺表面活性剂的磷脂酰胆碱（PC）成分，并将其与陆生哺乳动物进行比较。我们发现，与狗（家犬）相比，竖琴海豹（格陵兰海豹）和加利福尼亚海狮的抗黏附PC种类增加，并且与齿鲸类动物相比，鳍足类动物中具有流化作用的PC 16:0/14:0和16:0/16:1增加。港湾鼠海豚（齿鲸类动物的代表）与狗相比，具有流化作用的PC水平并不更高。我们的初步结果支持了先前的发现，即鳍足类动物可能已经适应了独特的表面活性剂成分，使其能够在高压下长时间潜水而不会产生不利影响。未来的研究需要调查其他表面活性剂成分的差异，以全面评估齿鲸类动物的表面活性剂组成。
