Lipid studies in breath-hold diving mammals and obese, pre-diabetic mice.

Young, Kathryn, 1984-

Lipid studies in breath-hold diving mammals and obese, pre-diabetic mice.

dc.contributor.advisor	Lee, Myeongwoo.
dc.contributor.author	Young, Kathryn, 1984-
dc.contributor.department	Biology.	en_US
dc.contributor.schools	Baylor University. Dept. of Biology.	en_US
dc.date.accessioned	2014-01-28T16:03:48Z
dc.date.available	2014-01-28T16:03:48Z
dc.date.copyright	2013-12
dc.date.issued	2014-01-28
dc.description.abstract	Lipidology, or the scientific investigation of cellular lipids in biological systems, as well as their pathways and networks, is becoming an increasingly integral component in the investigation of metabolic disease and, outside the healthcare fields, in the elucidation of adaptations to specific environmental stressors. Sphingolipid and whole phospholipid profiles were examined in several species of marine mammals (and in two tissue types in one marine mammal species), as well as in the skeletal muscle of obese, pre-diabetic mice. The fatty acid composition of the cells (the sum total of intracellular lipid and the fatty acids of membrane phospholipids) was also examined in obese, pre-diabetic skeletal muscle of the mouse. Marine mammal species were compared based on diving ability. Shallower divers (harbor seals, Phoca vitulina) demonstrated significantly higher C16 ceramide, 16:0 sphingomyelin, and dipalmitoylphosphatidylcholine (DPPC) levels compared to deeper divers (Weddell seals, Leptonychotes weddellii). Additionally, in comparing ringed seal (Pusa hispida) skeletal muscle to liver tissue, liver tissue showed significantly higher levels of C16:0 sphingomyelin, dipalmitoylphosphatidlycholine, and C16 ceramide. Pre-diabetic mice were found to have no significant changes in sphingolipids or whole phospholipids after high-fat diet (HFD) feeding compared to controls, but had statistically significant elevations of PUFAs (particularly omega-6s), and statistically significant declines in MUFAs. These results suggest that harbor seals are under greater stress than Weddell seals, based on upregulated levels of C16 ceramide and 16:0 sphingomyelin, and this increased stress likely results from an increased time at depth. Likewise, the liver of ringed seals shows significant signs of physiological stress, but here, the difference may be one of varying blood flow between the liver and skeletal muscle during diving. DPPC levels were higher in ringed seal liver, as well as harbor seal skeletal muscle, suggesting these tissues are more susceptible to hydrostatic pressure-related complications. Finally, the HFD-fed mice demonstrated a trend toward pro-inflammatory fatty acid pools with an increase in PUFAs, and specifically N6s. The results reported here contribute to our knowledge of the importance of biological membranes and the composition of fatty acid pools within cells to healthy physiological functioning.	en_US
dc.description.degree	Ph.D.	en_US
dc.identifier.citation	Young, K. E., Quinn, S. M., and Trumble, S. J. "Comparing gas chromatographic techniques used in fatty acid profiling of northern fur seals (Callorhinus ursinus) and Steller sea lions (Eumetopias jubatus) from Lovushki Island Complex, Russia." IJAST 2, 9 (2012): 11-21.	en_US
dc.identifier.uri	http://hdl.handle.net/2104/8925
dc.language.iso	en_US	en_US
dc.publisher		en
dc.rights	Baylor University theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact librarywebmaster@baylor.edu for inquiries about permission.	en_US
dc.rights.accessrights	Worldwide access.	en_US
dc.subject	Lipid studies.	en_US
dc.subject	Pre-diabetes.	en_US
dc.subject	Insulin resistance.	en_US
dc.subject	C57BL/6J mice.	en_US
dc.subject	Marine mammal.	en_US
dc.subject	Breath-hold diving.	en_US
dc.subject	Sphingolipids.	en_US
dc.subject	Phospholipids.	en_US
dc.subject	Ceramide.	en_US
dc.title	Lipid studies in breath-hold diving mammals and obese, pre-diabetic mice.	en_US
dc.type	Thesis	en_US