Static inflation and deflation pressure-volume curves from excised lungs of marine mammals.
Excised lungs from eight marine mammal species [harp seal (Pagophilus groenlandicus), harbor seal (Phoca vitulina), gray seal (Halichoerus grypush), 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.
Woods Hole Oceanographic Institution, 266 Woods Hole Road, MS 50, Woods Hole, MA 02543, USA. andreas_fahlman@yahoo.com
Andreas
A
Fahlman
Stephen H
SH
Loring
Massimo
M
Ferrigno
Colby
C
Moore
Greg
G
Early
Misty
M
Niemeyer
Betty
B
Lentell
Frederic
F
Wenzel
Ruth
R
Joy
Michael J
MJ
Moore
D000818:Animals; D004242:Diving / Q000502:physiology*; D004289:Dolphins / Q000502:physiology*; D008168:Lung / Q000502:physiology; D050741:Phocoena / Q000523:psychology*; D046048:Seals, Earless / Q000502:physiology*; D014109:Total Lung Capacity; D050686:Whales, Pilot / Q000502:physiology