Adipose tissue stearoyl-CoA desaturase 1 index is increased and linoleic acid is decreased in obesity-prone rats fed a high-fat diet.
Adipose tissue stearoyl-CoA desaturase 1 index is increased and linoleic acid is decreased in obesity-prone rats fed a high-fat diet.
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DOI：
10.1186/1476-511x-12-2
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发表时间：
2013-01-08
影响因子：
4.5
通讯作者：
Schiöth HB
中科院分区：
文献类型：
--
作者：
Cedernaes J;Alsiö J;Västermark A;Risérus U;Schiöth HB
脂肪酸 (FA) 组成和去饱和酶指数与肥胖和相关代谢状况相关。然而，目前尚不清楚不同脂质组分中的去饱和酶活性在多大程度上导致肥胖易感性。我们的目的是测试去饱和酶活性和 FA 组成是否与易肥胖 (OP) 或对高脂肪饮食 (HFD) 具有抵抗力 (OR) 的大鼠的肥胖表型相关。两组 Sprague-Dawley 大鼠被给予随意摄入 (AL-HFD) 或热量限制（HFD 配对；配对喂食由食物喂养的大鼠消耗的热量）的 HFD。 AL-HFD 组根据 5 周内的体重增加分为 OP 和 OR 亚组。在 OP 和 OR 大鼠中检查了五种不同的脂质组分，了解必需和超长链多不饱和 FA 的比例：亚油酸 (LA)、α-亚麻酸、二十碳五烯酸、二十二碳六烯酸和硬脂酰辅酶 A 去饱和酶 1 (SCD-1) 产物 16:1n-7。 FA比率用于估计δ-5-去饱和酶(20:4n-6/20:3n-6)、δ-6-去饱和酶(18:3n-6/18:2n-6)、硬脂酰辅酶A去饱和酶1(SCD-1；16:1n-7/16:0、SCD-16和18:1n-9/18:0、 SCD-18)、从头脂肪生成 (16:0/18:2n-6) 和 FA 伸长 (18:0/16:0)。测量血浆中的空腹胰岛素、葡萄糖、脂联素和瘦素浓度。与 OR 大鼠相比，接受 AL-HFD 治疗后，OP 大鼠的皮下脂肪组织 (SAT) 三酰甘油中的 SCD-16 指数和 16:1n-7 比例显着较高，但 LA 比例显着较低，胰岛素和瘦素浓度显着较高。在肝脏（磷脂；三酰甘油）或血浆（胆固醇酯；磷脂）脂质部分或血浆葡萄糖或脂联素浓度中，两种表型之间没有发现差异。对于 HFD 配对大鼠的去饱和酶指数，与 OP 或 OR 大鼠相比，唯一显着差异是 OP 中 SAT 三酰甘油的 SCD-16 和 SCD-18 指数高于 HFD 配对大鼠。较高的 SCD-16 可能反映了 SAT 中较高的 SCD-1 活性，这与较低的 LA 比例相结合可能反映了较高的胰岛素抵抗和独立于其他脂质部分的 SAT 变化。较低的 SCD-16 指数是否可以预防饮食引起的肥胖是一个有趣的可能性，值得进一步研究。
Fatty acid (FA) composition and desaturase indices are associated with obesity and related metabolic conditions. However, it is unclear to what extent desaturase activity in different lipid fractions contribute to obesity susceptibility. Our aim was to test whether desaturase activity and FA composition are linked to an obese phenotype in rats that are either obesity prone (OP) or resistant (OR) on a high-fat diet (HFD). Two groups of Sprague–Dawley rats were given ad libitum (AL-HFD) or calorically restricted (HFD-paired; pair fed to calories consumed by chow-fed rats) access to a HFD. The AL-HFD group was categorized into OP and OR sub-groups based on weight gain over 5 weeks. Five different lipid fractions were examined in OP and OR rats with regard to proportions of essential and very long-chain polyunsaturated FAs: linoleic acid (LA), alpha-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid and the stearoyl-CoA desaturase 1 (SCD-1) product 16:1n-7. FA ratios were used to estimate activities of the delta-5-desaturase (20:4n-6/20:3n-6), delta-6-desaturase (18:3n-6/18:2n-6), stearoyl-CoA desaturase 1 (SCD-1; 16:1n-7/16:0, SCD-16 and 18:1n-9/18:0, SCD-18), de novo lipogenesis (16:0/18:2n-6) and FA elongation (18:0/16:0). Fasting insulin, glucose, adiponectin and leptin concentrations were measured in plasma. After AL-HFD access, OP rats had a significantly higher SCD-16 index and 16:1n-7 proportion, but a significantly lower LA proportion, in subcutaneous adipose tissue (SAT) triacylglycerols, as well as significantly higher insulin and leptin concentrations, compared with OR rats. No differences were found between the two phenotypes in liver (phospholipids; triacylglycerols) or plasma (cholesterol esters; phospholipids) lipid fractions or for plasma glucose or adiponectin concentrations. For the desaturase indices of the HFD-paired rats, the only significant differences compared with the OP or OR rats were higher SCD-16 and SCD-18 indices in SAT triacylglycerols in OP compared with HFD-paired rats. The higher SCD-16 may reflect higher SCD-1 activity in SAT, which in combination with lower LA proportions may reflect higher insulin resistance and changes in SAT independent of other lipid fractions. Whether a lower SCD-16 index protects against diet-induced obesity is an interesting possibility that warrants further investigation.