title: Time-course metabolic changes in high-fat diet-induced obesity rats: A pilot study using hyperpolarized (13)C dynamic MRS.
abstract: The purpose of this study was to investigate the time-course metabolic changes based on hyperpolarized (13)C magnetic resonance spectroscopy (MRS) in high-fat diet (HFD)-induced obesity rats and the correlation between metabolic and serum enzyme levels. Sprague-Dawley rats were fed either HFD (60% fat) or normal diet (10% fat) for 6weeks. A HyperSense DNP was used to hyperpolarize [1-(13)C] pyruvic acid and the hyperpolarized (13)C MRS was examined every 2weeks in the course of 6weeks using a 3T GE MR750 scanner. The body weight of HFD-induced obese rats was significantly increased compared to normal rats at the 6th week after the onset of feeding (p=0.05). Simultaneously, the HFD-induced obese rats showed significantly increased levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and low-density lipoprotein (LDL)-cholesterol compared to normal rats (p≤0.05). In the dynamic (13)C MR spectra acquired at the 6th week, the obese rats showed significantly increased ratios of [1-(13)C] lactate/[1-(13)C] pyruvate and [1-(13)C] alanine/[1-(13)C] pyruvate (p=0.05). The (13)C spectral outcomes are positively correlated with the enzyme levels of ALT and LDH in the HFD-induced obesity. The [1-(13)C] lactate and [1-(13)C] alanine are potentially considered as noninvasive biomarkers for the HFD-induced obesity.
authors.affiliation: Research Institute for Medical Imaging, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Gwang-Won
authors.initials: GW
authors.lastname: Kim
authors.affiliation: Department of Anatomy, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Kyu-Youn
authors.initials: KY
authors.lastname: Ahn
authors.affiliation: Department of Radiology, Chonnam National University Medical School, Chonnam National University Hospital, Gwangju, Republic of Korea.
authors.forename: Yun-Hyeon
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Research Institute for Medical Imaging, Chonnam National University Medical School, Gwangju, Republic of Korea; Department of Radiology, Chonnam National University Medical School, Chonnam National University Hospital, Gwangju, Republic of Korea. Electronic address: gwjeong@jnu.ac.kr.
authors.forename: Gwang-Woo
authors.initials: GW
authors.lastname: Jeong
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001835:Body Weight; D059305:Diet, High-Fat; D004195:Disease Models, Animal; D007770:L-Lactate Dehydrogenase / Q000097:blood; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D009765:Obesity / Q000097:blood / Q000201:enzymology / Q000378:metabolism*; D010865:Pilot Projects; D019289:Pyruvic Acid / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D013995:Time
chemical_list: D015415:Biomarkers; D019289:Pyruvic Acid; D007770:L-Lactate Dehydrogenase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase
keywords: Dynamic nuclear polarization (DNP); Fatty liver; High-fat diet; Hyperpolarized (13)C; Time-course metabolic changes