Nitrogen solubility in odontocete blubber and mandibular fats in relation to lipid composition.
J Exp Biol
; 218(Pt 16): 2620-30, 2015 Aug.
Article
em En
| MEDLINE
| ID: mdl-26290593
ABSTRACT
Understanding toothed whale (odontocete) diving gas dynamics is important given the recent atypical mass strandings of odontocetes (particularly beaked whales) associated with mid-frequency naval sonar. Some stranded whales have exhibited gas emboli (pathologies resembling decompression sickness) in their specialized intramandibular and extramandibular fat bodies used for echolocation and hearing. These tissues have phylogenetically unique, endogenous lipid profiles with poorly understood biochemical properties. Current diving gas dynamics models assume an Ostwald nitrogen (N2) solubility of 0.07â
ml N2 ml(-1) oil in odontocete fats, although solubility in blubber from many odontocetes exceeds this value. The present study examined N2 solubility in the blubber and mandibular fats of seven species across five families, relating it to lipid composition. Across all species, N2 solubility increased with wax ester content and was generally higher in mandibular fats (0.083 ± 0.002â
ml N2 ml(-1) oil) than in blubber (0.069 ± 0.007â
ml N2 ml(-1) oil). This effect was more pronounced in mandibular fats with higher concentrations of shorter, branched fatty acids/alcohols. Mandibular fats of short-finned pilot whales, Atlantic spotted dolphins and Mesoplodon beaked whales had the highest N2 solubility values (0.097 ± 0.005, 0.081 ± 0.007 and 0.080 ± 0.003â
ml N2 ml(-1) oil, respectively). Pilot and beaked whales may experience high N2 loads during their relatively deeper dives, although more information is needed about in vivo blood circulation to mandibular fats. Future diving models should incorporate empirically measured N2 solubility of odontocete mandibular fats to better understand N2 dynamics and potential pathologies from gas/fat embolism.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cetáceos
/
Tecido Adiposo
/
Lipídeos
/
Nitrogênio
Limite:
Animals
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article