Static inflation and deflation pressure-volume curves from excised lungs of marine mammals

• Published in: Journal of Experimental Biology
• Main Authors: Fahlman, Andreas, Loring, Stephen H., Ferrigno, Massimo, Moore, Colby, Early, Greg, Niemeyer, Misty, Lentell, Betty, Wenzel, Frederic, Joy, Ruth, Moore, Michael J.
• Format: Text
• Language: English
• Published: Company of Biologists 2011
• Subjects: Research Articles; harbor seal; Harp Seal; Pagophilus groenlandicus; Phoca vitulina; Phocoena phocoena
• Online Access: http://jeb.biologists.org/cgi/content/short/214/22/3822; https://doi.org/10.1242/jeb.056366

Excised lungs from eight marine mammal species [harp seal ( Pagophilus groenlandicus ), harbor seal ( Phoca vitulina ), gray seal ( Halichoerus grypus h), Atlantic white-sided dolphin ( Lagenorhynchus acutus ), common dolphin ( Delphinus delphis ), Risso's dolphin ( Grampus griseus ), long-finned pilot whale ( Globicephala melas ) and harbor porpoise ( Phocoena phocoena )] were used to determine the minimum air volume of the relaxed lung (MAV, N =15), the elastic properties (pressure–volume curves, N =24) of the respiratory system and the total lung capacity (TLC). Our data indicate that mass-specific TLC (sTLC, l kg–1) does not differ between species or groups (odontocete vs phocid) and agree with that estimated (TLC est ) from body mass ( M b ) by applying the equation: TLC est =0.135 M b 0.92. Measured MAV was on average 7% of TLC, with a range from 0 to 16%. The pressure–volume curves were similar among species on inflation but diverged during deflation in phocids in comparison with odontocetes. These differences provide a structural basis for observed species differences in the depth at which lungs collapse and gas exchange ceases.