Oxygenating blubber: a challenge for fat animals

Laura Oller; Joel Rocha; J. Chris McKnight; Mark Dagleish; Kimberley Bennett

Abstract

Large fat depots are associated comorbidities in humans. Biomedical studies show that tissue expansion leads to structural tissue modifications and potential hypoxia as result of low vascularity or impaired diffusion due to large adipocyte size. How blubber maintains adequate oxygenation and readjust tissue structure is unknown. Here, we examine blubber depth and fatness effects on tissue oxygenation and blubber characteristics. Blubber dissolved oxygen levels (pO₂) were measured in dorsal flank blubber on juvenile grey seals (n=10) under appropriate sedation and anaesthesia. Measurements were taken at different blubber depths, with an optical, non-consuming oxygen probe. Oxygen supply was investigated recording systemic blood saturation (SpO₂), breathing rate and oxy-haemoglobin and deoxygenated haemoglobin. The later was measured using a novel non-invasive technique: Near Infrared Spectroscopy (NIRS). Body composition and heart rate were also recorded. To examine vascularity and tissue structure changes throughout depth and fatness, full blubber depth biopsies of mother and pup pairs were taken at early and late lactation (n = 6). Biopsies were fixed in formalin, processed and stained with Masson’s Trichrome. Each biopsy was divided into three sections, and five images of each section were analysed by Image J. In vivo oxygen measurements ranged between 11 mmHg and 59 mmHg (mean = 32 mmHg), consistent with levels on other species. Linear mixed effect analysis (LMM) showed that tissue oxygenation had a significant positive relation with SpO₂ (p-value = 0.04) and a negative relationship with depth section (p-value Inner vs Outer = 0.02; p-value Inner vs Middle = 0.17; p-value Outer vs Middle = 0.46) and fatness (p-value = 0.04), independently of the individual (R²_marginal = 0.59, R²_conditional = 0.59). Results show that tissue expansion is also a challenge for seals. NIRS and histology data analysis are underway to explore oxygen supply, vascularity and tissue structure role on oxygenation.

Original language	English
Publication status	Published - 10 Dec 2019
Event	World Marine Mammal Conference 2019 - Centre de Convencions Internacional de Barcelona, Barcelona, Spain Duration: 9 Dec 2019 → 12 Dec 2019 https://www.wmmconference.org/wp-content/uploads/2019/12/WMMC2019-PDF-Program_Dec_2019.pdf

Conference

Conference	World Marine Mammal Conference 2019
Abbreviated title	WMMC'19
Country/Territory	Spain
City	Barcelona
Period	9/12/19 → 12/12/19
Internet address	https://www.wmmconference.org/wp-content/uploads/2019/12/WMMC2019-PDF-Program_Dec_2019.pdf

Cite this

@conference{6bc271956c7148c5848d150176728f2d,

title = "Oxygenating blubber: a challenge for fat animals",

abstract = "Large fat depots are associated comorbidities in humans. Biomedical studies show that tissue expansion leads to structural tissue modifications and potential hypoxia as result of low vascularity or impaired diffusion due to large adipocyte size. How blubber maintains adequate oxygenation and readjust tissue structure is unknown. Here, we examine blubber depth and fatness effects on tissue oxygenation and blubber characteristics. Blubber dissolved oxygen levels (pO2) were measured in dorsal flank blubber on juvenile grey seals (n=10) under appropriate sedation and anaesthesia. Measurements were taken at different blubber depths, with an optical, non-consuming oxygen probe. Oxygen supply was investigated recording systemic blood saturation (SpO2), breathing rate and oxy-haemoglobin and deoxygenated haemoglobin. The later was measured using a novel non-invasive technique: Near Infrared Spectroscopy (NIRS). Body composition and heart rate were also recorded. To examine vascularity and tissue structure changes throughout depth and fatness, full blubber depth biopsies of mother and pup pairs were taken at early and late lactation (n = 6). Biopsies were fixed in formalin, processed and stained with Masson{\textquoteright}s Trichrome. Each biopsy was divided into three sections, and five images of each section were analysed by Image J. In vivo oxygen measurements ranged between 11 mmHg and 59 mmHg (mean = 32 mmHg), consistent with levels on other species. Linear mixed effect analysis (LMM) showed that tissue oxygenation had a significant positive relation with SpO2 (p-value = 0.04) and a negative relationship with depth section (p-value Inner vs Outer = 0.02; p-value Inner vs Middle = 0.17; p-value Outer vs Middle = 0.46) and fatness (p-value = 0.04), independently of the individual (R2marginal = 0.59, R2conditional = 0.59). Results show that tissue expansion is also a challenge for seals. NIRS and histology data analysis are underway to explore oxygen supply, vascularity and tissue structure role on oxygenation.",

author = "Laura Oller and Joel Rocha and McKnight, {J. Chris} and Mark Dagleish and Kimberley Bennett",

year = "2019",

month = dec,

day = "10",

language = "English",

note = "World Marine Mammal Conference 2019, WMMC'19 ; Conference date: 09-12-2019 Through 12-12-2019",

url = "https://www.wmmconference.org/wp-content/uploads/2019/12/WMMC2019-PDF-Program_Dec_2019.pdf",

}

TY - CONF

T1 - Oxygenating blubber

T2 - World Marine Mammal Conference 2019

AU - Oller, Laura

AU - Rocha, Joel

AU - McKnight, J. Chris

AU - Dagleish, Mark

AU - Bennett, Kimberley

PY - 2019/12/10

Y1 - 2019/12/10

N2 - Large fat depots are associated comorbidities in humans. Biomedical studies show that tissue expansion leads to structural tissue modifications and potential hypoxia as result of low vascularity or impaired diffusion due to large adipocyte size. How blubber maintains adequate oxygenation and readjust tissue structure is unknown. Here, we examine blubber depth and fatness effects on tissue oxygenation and blubber characteristics. Blubber dissolved oxygen levels (pO2) were measured in dorsal flank blubber on juvenile grey seals (n=10) under appropriate sedation and anaesthesia. Measurements were taken at different blubber depths, with an optical, non-consuming oxygen probe. Oxygen supply was investigated recording systemic blood saturation (SpO2), breathing rate and oxy-haemoglobin and deoxygenated haemoglobin. The later was measured using a novel non-invasive technique: Near Infrared Spectroscopy (NIRS). Body composition and heart rate were also recorded. To examine vascularity and tissue structure changes throughout depth and fatness, full blubber depth biopsies of mother and pup pairs were taken at early and late lactation (n = 6). Biopsies were fixed in formalin, processed and stained with Masson’s Trichrome. Each biopsy was divided into three sections, and five images of each section were analysed by Image J. In vivo oxygen measurements ranged between 11 mmHg and 59 mmHg (mean = 32 mmHg), consistent with levels on other species. Linear mixed effect analysis (LMM) showed that tissue oxygenation had a significant positive relation with SpO2 (p-value = 0.04) and a negative relationship with depth section (p-value Inner vs Outer = 0.02; p-value Inner vs Middle = 0.17; p-value Outer vs Middle = 0.46) and fatness (p-value = 0.04), independently of the individual (R2marginal = 0.59, R2conditional = 0.59). Results show that tissue expansion is also a challenge for seals. NIRS and histology data analysis are underway to explore oxygen supply, vascularity and tissue structure role on oxygenation.

AB - Large fat depots are associated comorbidities in humans. Biomedical studies show that tissue expansion leads to structural tissue modifications and potential hypoxia as result of low vascularity or impaired diffusion due to large adipocyte size. How blubber maintains adequate oxygenation and readjust tissue structure is unknown. Here, we examine blubber depth and fatness effects on tissue oxygenation and blubber characteristics. Blubber dissolved oxygen levels (pO2) were measured in dorsal flank blubber on juvenile grey seals (n=10) under appropriate sedation and anaesthesia. Measurements were taken at different blubber depths, with an optical, non-consuming oxygen probe. Oxygen supply was investigated recording systemic blood saturation (SpO2), breathing rate and oxy-haemoglobin and deoxygenated haemoglobin. The later was measured using a novel non-invasive technique: Near Infrared Spectroscopy (NIRS). Body composition and heart rate were also recorded. To examine vascularity and tissue structure changes throughout depth and fatness, full blubber depth biopsies of mother and pup pairs were taken at early and late lactation (n = 6). Biopsies were fixed in formalin, processed and stained with Masson’s Trichrome. Each biopsy was divided into three sections, and five images of each section were analysed by Image J. In vivo oxygen measurements ranged between 11 mmHg and 59 mmHg (mean = 32 mmHg), consistent with levels on other species. Linear mixed effect analysis (LMM) showed that tissue oxygenation had a significant positive relation with SpO2 (p-value = 0.04) and a negative relationship with depth section (p-value Inner vs Outer = 0.02; p-value Inner vs Middle = 0.17; p-value Outer vs Middle = 0.46) and fatness (p-value = 0.04), independently of the individual (R2marginal = 0.59, R2conditional = 0.59). Results show that tissue expansion is also a challenge for seals. NIRS and histology data analysis are underway to explore oxygen supply, vascularity and tissue structure role on oxygenation.

M3 - Abstract

Y2 - 9 December 2019 through 12 December 2019

ER -

Oxygenating blubber: a challenge for fat animals

Abstract

Conference

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