Biochemistry Division, National Institute of Nutrition, Jamai Osmania, Hyderabad-500 604, India.
Nutr Metab (Lond). 2009 Jun 11;6:27. doi: 10.1186/1743-7075-6-27.
Microsomal stearoyl-CoA desaturase1 (SCD1) is the rate limiting enzyme involved in the biosynthesis of monounsaturated fatty acids (MUFAs); palmitoleic (16:1) and oleic (18:1) acid from their respective substrates palmitic (16:0) and stearic (18:0) acids. The ratio of 18:1 to 18:0 has been implicated in the regulation membrane fluidity and function. SCD1 is abundantly expressed in obese humans as well as rodent models. However, no studies have correlated the fatty acid desaturation index (16:1/16:0 and 18:1/18:0), an indicator of SCD1 activity with the markers of obesity in terms of body mass index (BMI) and adiposity index (AI). Therefore, here, we attempted to relate the fatty acid desaturation index with BMI and AI in Wistar NIN-obese mutant rat strains namely, WNIN/Ob and WNIN/GR-Ob (with impaired glucose tolerance).
For this purpose, 200 days old male 6 lean and 6 obese rats of both strains were taken. Fatty acid composition was analyzed in plasma, various tissues such as liver, white adipose tissues (retroperitoneal, epididymal, omental, and subcutaneous) and brown adipose tissue.
Fatty acid composition data showed significant increase in palmitoleic (16:1) and oleic (18:1) acid levels, which were reflected in increased desaturation index (16:1/16:0 and 18:1/18:0) in plasma and all the tissues of obese rats of both strains, when compared with their respective age and sex-matched lean rats. Further, we found a strong positive correlation between desaturation index, BMI and AI in plasma and most of the tissues analyzed.
So far, plasma Δ⁹ desaturation index has been well correlated with hypertriglyceridemia and we, by employing two models of obesity namely, WNIN/Ob and WNIN/GR-Ob, have shown Δ⁹ desaturation index of plasma correlated with physical markers of obesity such as BMI and AI. In conclusion, Δ⁹ desaturation index may serve as a potential sensitive biochemical marker to assess the degree of obesity and impact of therapeutic/nutritional interventions to combat obesity, along with other indicators.
微粒体硬脂酰辅酶 A 去饱和酶 1（SCD1）是参与单不饱和脂肪酸（MUFAs）生物合成的限速酶；从各自的底物棕榈酸（16:0）和硬脂酸（18:0）生成棕榈油酸（16:1）和油酸（18:1）酸。18:1 与 18:0 的比例与调节膜流动性和功能有关。SCD1 在肥胖人群以及啮齿动物模型中大量表达。然而，尚未有研究将脂肪酸去饱和指数（16:1/16:0 和 18:1/18:0）与肥胖标志物（体重指数（BMI）和肥胖指数（AI））相关联。因此，在这里，我们试图将脂肪酸去饱和指数与 Wistar NIN-肥胖突变大鼠品系（WNIN/Ob 和 WNIN/GR-Ob，伴有葡萄糖耐量受损）的 BMI 和 AI 相关联。
为此，取 6 只 lean 大鼠和 6 只肥胖大鼠，雄性，200 天大，来自两个品系。分析了血浆、肝脏、白色脂肪组织（腹膜后、附睾、网膜和皮下）和棕色脂肪组织等各种组织中的脂肪酸组成。
脂肪酸组成数据显示，棕榈油酸（16:1）和油酸（18:1）酸水平显著升高，这反映在两个品系肥胖大鼠的血浆和所有组织中的去饱和指数（16:1/16:0 和 18:1/18:0）升高，与各自年龄和性别匹配的 lean 大鼠相比。此外，我们发现去饱和指数与 BMI 和 AI 之间在血浆和大多数分析组织中呈强正相关。
到目前为止，血浆 Δ⁹ 去饱和指数与高甘油三酯血症密切相关，我们通过采用 WNIN/Ob 和 WNIN/GR-Ob 两种肥胖模型，表明血浆 Δ⁹ 去饱和指数与 BMI 和 AI 等肥胖的物理标志物相关。总之，Δ⁹ 去饱和指数可以作为评估肥胖程度和评估治疗/营养干预对肥胖影响的潜在敏感生化标志物，以及其他指标。
