Evaluation of Visceral Adipose Tissue Oxygenation by Blood Oxygen Level-Dependent MRI in Zucker Diabetic Fatty Rats.

Shi, Hong‐Jian; Li, Yan‐Feng; Lin, Zhi‐Chun; Chen, Tao; Yuan, Bin; Yuan, Fei; Ji, Wen‐Jie; Cai, Wei; Niu, Xiu‐Long; Li, Han‐Ying; Shu, Wen; Li, Yu‐Ming; Zhou, Xin; Zhang, Zhuoli; Shi, Hong-Jian; Li, Yan-Feng; Ji, Wen-Jie; Lin, Zhi-Chun; Niu, Xiu-Long; Li, Han-Ying

Objective: This study aimed to investigate the feasibility of blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to evaluate visceral adipose tissue (VAT) oxygenation in Zucker diabetic fatty (ZDF) rats and its associations with systemic metaflammation.Methods: Five-week-old ZDF rats and Zucker lean (ZL) rats were fed a high-fat diet (HFD) for 18 weeks. A baseline BOLD-MRI scan of perirenal adipose tissue was performed after 8 weeks of HFD feeding, and then the rats were randomized to receive pioglitazone or a vehicle for the following 10 weeks. At sacrifice, BOLD-MRI scan, Hypoxyprobe-1 injection, and circulating T helper 17 (Th17), regulatory T (Treg) cells, and monocyte subtype flow cytometry analysis were performed.Results: HFD feeding led to a significant increase in VAT BOLD-MRI R2* signals (20.14 ± 0.23 per second vs. 21.53 ± 0.20 per second; P = 0.012), an indicator for decreased oxygenation. R2* signal was significantly correlated with VAT pimonidazole adduct-positive area, insulin resistance, Th17 and Treg cells, CD43 and CD43 monocyte subtypes, and VAT macrophage infiltration. Pioglitazone treatment improved the insulin resistance and was associated with a delayed progression of VAT oxygenation.Conclusions: This work demonstrated the feasibility of BOLD-MRI for detecting the VAT oxygenation status in ZDF rats, and the BOLD-MRI signals were associated with insulin resistance and systemic metaflammation in ZDF rats during the development of obesity.

OXYGENATORS; MAGNETIC resonance imaging; ADIPOSE tissues; OXYGENATION (Chemistry); DIABETIC acidosis; PIOGLITAZONE; CYTOMETRY

Obesity (19307381), 2018, Vol 26, Issue 6, p1017

1930-7381

Academic Journal

10.1002/oby.22191