Data on the phospholipid fatty acyl composition of retroperitoneal white adipose tissue in ad libitum fed and fasted mice

Data are presented on the fatty acyl composition of phospholipid from retroperitoneal white adipose tissue of female mice that were either given ad libitum access to food or fasted for 16 h overnight prior to sacrifice. Our data show that total adipose phospholipid concentrations were more than 2-fold higher in the fasted animals compared with the fed animals (33.48±7.40 versus 16.57±4.43 μg phospholipid fatty acids/100 mg tissue). Concentrations of several individual phospholipid fatty acyl species, including palmitic acid (16:0), vaccenic acid (18:1n-7), linoleic acid (18:2n-6), dihomo-gamma-linolenic acid (20:3n-6), arachidonic acid (20:4n-6), eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3), as well as total phospholipid saturated fatty acids, n-6 polyunsaturated fatty acids and n-3 polyunsaturated fatty acids, were significantly higher in adipose tissue from the fasted animals compared with the fed animals. However, when the relative abundance of phospholipid fatty acyl species was analyzed, only 20:4n-6 was specifically enriched (by ~2.5-fold) in adipose phospholipid with fasting.


a b s t r a c t
Data are presented on the fatty acyl composition of phospholipid from retroperitoneal white adipose tissue of female mice that were either given ad libitum access to food or fasted for 16 h overnight prior to sacrifice. Our data show that total adipose phospholipid concentrations were more than 2-fold higher in the fasted animals compared with the fed animals (33.4877.40 versus 16.5774.43 μg phospholipid fatty acids/100 mg tissue). Concentrations of several individual phospholipid fatty acyl species, including palmitic acid (16:0), vaccenic acid (18:1n-7), linoleic acid (18:2n-6), dihomogamma-linolenic acid (20:3n-6), arachidonic acid (20:4n-6), eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3), as well as total phospholipid saturated fatty acids, n-6 polyunsaturated fatty acids and n-3 polyunsaturated fatty acids, were significantly higher in adipose tissue from the fasted animals compared with the fed animals. However, when the relative abundance of phospholipid fatty acyl species was analyzed, only 20:4n-6 was specifically enriched (by $ 2.

Subject area
Biology, chemistry More specific subject area

Lipid biochemistry
Type of data Gas chromatography, Table  How  These data are of value to researchers interested in adipose tissue biology. These data are of value to researchers interested in phospholipid metabolism. These data are of value to researchers studying bioactive polyunsaturated fatty acids such as arachidonic acid and docosahexaenoic acid.
Data from fasted compared to non-fasted animals are of value to researchers for use in planning optimal metabolic conditions for experiments.

Animals
All animal procedures were approved by the University of Waterloo Animal Care Committee and were in accordance with the guidelines of the Canadian Council on Animal Care. Female C57Bl/6J mice, aged 12-16 weeks, were housed in the Central Animal Housing Facility at the University of Waterloo with ad libitum access to a low-fat diet (D12450H, Research Diets Inc., New Jersey, U.S.A.) and water, at a temperature of 21 71°C on a 12:12-h light-dark cycle. The fatty acid profile of the diet has been reported previously [1]. Prior to sacrifice by cervical dislocation, animals were either fasted overnight for 16 h or maintained with ad libitum access to food. Adipose tissue was collected and immediately frozen in liquid nitrogen, and stored at À 80°C until lipid analysis [1].

Fatty acid composition
Adipose lipids were extracted with 2:1 chloroform:methanol (v:v) based on the method of Folch, Lees and Sloane Stanley [2]. Thin layer chromatography, using 20 Â 20 cm 2 plates with a 60 Ǻ silica gel layer (Whatman International LTD, Maidstone, England), with a mobile phase of 60:40:2 heptane: diethyl ether: acetic acid (v:v:v) [3] was used to isolate phospholipids. Bands were visualized under UV light with 2,7-dichlorofluorescein (Sigma-Aldrich, Oakville, ON), and identified by comparison to a reference standard. Lipids were extracted off the silica using 2:1 chloroform:methanol with 22:3n-3 as an internal standard, and transesterified by 14% BF 3 in methanol at 95°C for 1 h to produce fatty acid methyl esters [4], which were separated by fast-gas chromatography [5,6]. Peaks were identified by comparison of the retention time to a reference mixture of fatty acids (GLC-569, Nu-Chek Prep Inc). Fatty acids were quantitated by comparison to the internal standard and expressed as mg fatty acid/ 100 mg adipose tissue.  N ¼3-4 mice per group, data are mean7 SD. SFAs: total saturated fatty acids; MUFAs: total monounsaturated fatty acids; N-6: total n-6 polyunsaturated fatty acids; N-3: total n-3 polyunsaturated fatty acids. n po 0.05.

Statistical analysis
The data are expressed as mean 7SD. Statistically significant differences between two groups were assessed by Student's t-test. Significance is inferred at p o0.05.

Acknowledgments
Funding for this study was provided by grants to RED and KDS from the Natural Sciences and Engineering Research Council of Canada (#418213-2012), the Canada Foundation for Innovation, and the Ontario Research Fund for Research Infrastructure (Project#30259). KAM was supported by an Ontario Women's Health Doctoral Scholarship and is the recipient of an Ontario Graduate Scholarship, and KDS is supported through a Canada Research Chair in Nutritional Lipidomics. The authors declare no conflicts of interest. N ¼3-4 mice per group, data are mean7 SD. SFAs: total saturated fatty acids; MUFAs: total monounsaturated fatty acids; N-6: total n-6 polyunsaturated fatty acids; N-3: total n-3 polyunsaturated fatty acids n po 0.05.