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

Fahlman, Andreas; Loring, Stephen H.; Ferrigno, Massimo; Moore, Colby D.; Early, Greg; Niemeyer, Misty; Lentell, Betty J.; Wenzel, Frederic; Joy, Ruth; Moore, Michael J.

doi:10.1242/jeb.056366

Cited by 41 publications

(79 citation statements)

References 21 publications

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“…4), but was significantly higher during chuffs (11.9±3.7 l, AIC null =1099.2, AIC breath-type =913.3) compared with spontaneous breaths (5.7±1.7 l, P<0.01). The largest tidal volume recorded during this study was 18.4 l for Kolohe (94 ml kg −1 ), which was greater than that animal's estimated total lung capacity (TLC est ) of 17.3 l, based on models from excised lungs (TLCest=0.135M b 0.92 see references Fahlman et al, 2011;Kooyman, 1973).…”

Section: −1mentioning

confidence: 56%

“…Theoretical modeling work indicates that the structural properties (e.g. compliance) of the various parts of the respiratory system dictate how pressure affects the distribution of gas between conducting airways and alveolar space (Bostrom et al, 2008;Fahlman et al, 2009Fahlman et al, , 2011Fitz-Clarke, 2007). High pulmonary compliance may be an important component of minimizing transpulmonary pressure gradients Leith, 1976Leith, , 1989Ridgway et al, 1969), and has also been suggested to reduce the risk of elevated blood and tissue N 2 levels, thereby minimizing the risk for DCS (Ridgway and Howard, 1979;Scholander, 1940).…”

Section: Introductionmentioning

confidence: 99%

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Lung mechanics and pulmonary function testing in cetaceans

Fahlman

Loring

Levine³

et al. 2015

Journal of Experimental Biology

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126

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We measured esophageal pressures, respiratory flow rates, and expired O 2 and CO 2 in six adult bottlenose dolphins (Tursiops truncatus) during voluntary breaths and maximal (chuff ) respiratory efforts. The data were used to estimate the dynamic specific lung compliance (sC L ), the O 2 consumption rate (V O2 ) and CO 2 production rates (V CO2 ) during rest. ). The average estimated V O2 and V CO2 using our breath-by-breath respirometry system ranged from 0.857 to 1.185 l O 2 min −1 and 0.589 to 0.851 l CO 2 min, respectively, which is similar to previously published metabolic measurements from the same animals using conventional flow-through respirometry. In addition, our custom-made system allows us to approximate end tidal gas composition. Our measurements provide novel data for respiratory physiology in cetaceans, which may be important for clinical medicine and conservation efforts.

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Section: −1mentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Lung mechanics and pulmonary function testing in cetaceans

Fahlman

Loring

Levine³

et al. 2015

Journal of Experimental Biology

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126

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“…The structural properties of the lungs were measured and have been discussed in a separate publication (Fahlman et al, 2011). The trachea was separated from the lungs and excess associated tissue was removed.…”

Section: Protocolmentioning

confidence: 99%

“…The relationship between pressure and volume gives an estimate of the compliance of the respiratory tract and has been successfully performed on excised lungs from terrestrial mammals (Bachofen et al, 1970), with few data documenting compliance of marine mammal lungs (Denison et al, 1971;Piscitelli et al, 2010;Fahlman et al, 2011). The compliance of the trachea has been suggested to affect the amount of air displaced from the lungs (Bostrom et al, 2008), and thereby the depth where the alveoli collapse and gas exchange ceases.…”

Section: Introductionmentioning

confidence: 99%

A comparative analysis of marine mammal tracheas

Moore

Trumble

et al. 2013

Journal of Experimental Biology

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In 1940, Scholander suggested that stiffened upper airways remained open and received air from highly compressible alveoli during marine mammal diving. There are few data available on the structural and functional adaptations of the marine mammal respiratory system. The aim of this research was to investigate the anatomical (gross) and structural (compliance) characteristics of excised marine mammal tracheas. Here, we defined different types of tracheal structures, categorizing pinniped tracheas by varying degrees of continuity of cartilage (categories 1-4) and cetacean tracheas by varying compliance values (categories 5A and 5B). Some tracheas fell into more than one category along their length; for example, the harbor seal (Phoca vitulina) demonstrated complete rings cranially, and as the trachea progressed caudally, tracheal rings changed morphology. Dolphins and porpoises had less stiff, more compliant spiraling rings while beaked whales had very stiff, less compliant spiraling rings. The pressure-volume (P-V) relationships of isolated tracheas from different species were measured to assess structural differences between species. These findings lend evidence for pressure-induced collapse and re-inflation of lungs, perhaps influencing variability in dive depth or ventilation rates of the species investigated.

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“…These data will be used to calculate airway resistance, pulmonary and thoracic compliance (pressure-volume relationship). The static compliance values will be compared to the data previously determined in postmortem marine mammals [11].…”

Section: Approachmentioning

confidence: 99%