title: High-Fat Diet Alters Serum Fatty Acid Profiles in Obesity Prone Rats: Implications for In Vitro Studies.
abstract: High-fat diets (HFD) are commonly used in rodents to induce obesity, increase serum fatty acids and induce lipotoxicity in various organs. In vitro studies commonly utilize individual free fatty acids (FFA) to study lipid exposure in an effort to model what is occurring in vivo; however, these approaches are not physiological as tissues are exposed to multiple fatty acids in vivo. Here we characterize circulating lipids in obesity-prone rats fed an HFD in both fasted and fed states with the goal of developing physiologically relevant fatty acid mixtures for subsequent in vitro studies. Rats were fed an HFD (60% kcal fat) or a control diet (10% kcal fat) for 3 weeks; liver tissue and both portal and systemic blood were collected. Fatty acid profiles and absolute concentrations of triglycerides (TAG) and FFA in the serum and TAG, diacylglycerol (DAG) and phospholipids in the liver were measured. Surprisingly, both systemic and portal serum TAG were ~40% lower in HFD-fed compared to controls. Overall, compared to the control diet, HFD feeding consistently induced an increase in the proportion of circulating polyunsaturated fatty acids (PUFA) with a concomitant decline in monounsaturated fatty acids (MUFA) and saturated fatty acids (SFA) in both serum TAG and FFA. The elevations of PUFA were mostly attributed to increases in n-6 PUFA, linoleic acid and arachidonic acid. In conclusion, fatty acid mixtures enriched with linoleic and arachidonic acid in addition to SFA and MUFA should be utilized for in vitro studies attempting to model lipid exposures that occur during in vivo HFD conditions.
authors: Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, 65211, USA. tliu42@illinois.edu.|Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA. tliu42@illinois.edu.
authors: Tzu-Wen
authors: TW
authors: Liu
authors: Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, 65211, USA. hedent14@ecu.edu.|Department of Kinesiology, East Carolina University, Greenville, NC, 27843, USA. hedent14@ecu.edu.
authors: Timothy D
authors: TD
authors: Heden
authors: Molecular and Integrative Physiology, University of Kansas Medical Center, 2067 Hemenway Life Sciences and Innovation Center, MS: 3043, 3901 Rainbow Blvd, Kansas, KS, 66160, USA. morrisem@health.missouri.edu.
authors: E
authors: E
authors: Matthew Morris
authors: Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, 65211, USA. FritscheK@missouri.edu.|Animal Sciences, University of Missouri, Columbia, MO, 65211, USA. FritscheK@missouri.edu.
authors: Kevin L
authors: KL
authors: Fritsche
authors: Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, 65211, USA. vieirapotterv@missouri.edu.
authors: Victoria J
authors: VJ
authors: Vieira-Potter
authors: Molecular and Integrative Physiology, University of Kansas Medical Center, 2067 Hemenway Life Sciences and Innovation Center, MS: 3043, 3901 Rainbow Blvd, Kansas, KS, 66160, USA. jthyfault@kumc.edu.|Research Service, Kansas City VA Medical Center, Kansas, MO, 64128, USA. jthyfault@kumc.edu.
authors: John P
authors: JP
authors: Thyfault
mesh_terms: D000818:Animals; D059305:Diet, High-Fat / Q000009:adverse effects*; D004075:Diglycerides / Q000378:metabolism; D004195:Disease Models, Animal; D005227:Fatty Acids / Q000097:blood* / Q000378:metabolism; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008297:Male; D009765:Obesity / Q000097:blood* / Q000209:etiology / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
chemical_list: D004075:Diglycerides; D005227:Fatty Acids; D010743:Phospholipids; D014280:Triglycerides
keywords: Development of obesity; Fatty acids; HFD; PUFA