Abadie J M, Malcom G T, Porter J R, Svec F
Department of Pathology, Louisiana State University Medical Center, New Orleans 70112, USA.
Lipids. 2000 Jun;35(6):613-20. doi: 10.1007/s11745-000-0564-4.
High free fatty acid (FFA) levels are common in obesity and in diseases such as diabetes that are associated with the obese state. Dehydroepiandrosterone (DHEA) decreases dietary fat consumption, body fat content, and insulin levels in the obese Zucker rat (ZR), a genetic model of human youth-onset obesity and type 2 diabetes mellitus. This study was conducted to investigate the effects of DHEA on lean and obese ZR serum, adipose, and hepatic tissue fatty acid (FA) profiles and serum FFA levels. Because DHEA is known to decrease fat consumption and body fat, we postulate that DHEA may also alter FA profiles and FFA levels of the obese ZR such that they more closely resemble the profiles and levels of their lean siblings. In this study there was a DHEA and a pair-fed (PF) group (n = 6) for 12 lean and 12 obese ZR. The diet of the treatment groups was supplemented with 0.6% DHEA, and PF groups were given the same average calories consumed by their corresponding DHEA group for 30 d. Fasted animals were sacrificed, and FA profiles and FFA levels were measured. Serum FFA levels were higher in obese (approximately 1 mmol/L) compared to lean rats (approximately 0.6 mmol/L). After 30 d of DHEA treatment, FFA levels were lower (P < 0.05) in both lean and obese groups. Although several significant differences in FA profile of serum, hepatic, and adipose lipid components were observed between lean and obese ZR, DHEA-related changes were only observed in the serum phospholipid (PL) and liver PL and triglyceride fractions. The slight but significant decrease in serum FFA levels may be reflected by changes in serum PL FA profiles. Specific hepatic FA profile alterations may be related to DHEA's known effects in inducing hepatic peroxisomes. We speculate that such FA changes may give insight into a mechanism for the action of DHEA.
高游离脂肪酸(FFA)水平在肥胖症以及与肥胖状态相关的疾病(如糖尿病)中很常见。脱氢表雄酮(DHEA)可降低肥胖Zucker大鼠(ZR)的饮食脂肪摄入量、体脂含量和胰岛素水平,肥胖ZR是人类青少年期肥胖和2型糖尿病的遗传模型。本研究旨在探讨DHEA对瘦型和肥胖型ZR血清、脂肪组织和肝脏组织脂肪酸(FA)谱以及血清FFA水平的影响。由于已知DHEA可减少脂肪消耗和体脂,我们推测DHEA也可能改变肥胖ZR的FA谱和FFA水平,使其更接近其瘦型同胞的谱和水平。在本研究中,对于12只瘦型和12只肥胖型ZR,分别设置了一个DHEA组和一个配对喂养(PF)组(n = 6)。治疗组的饮食中添加了0.6%的DHEA,PF组给予其相应DHEA组消耗的相同平均热量,持续30天。对禁食的动物进行处死,并测量FA谱和FFA水平。与瘦型大鼠(约0.6 mmol/L)相比,肥胖大鼠的血清FFA水平更高(约1 mmol/L)。DHEA治疗30天后,瘦型和肥胖型组的FFA水平均降低(P < 0.05)。尽管在瘦型和肥胖型ZR之间观察到血清、肝脏和脂肪脂质成分的FA谱存在若干显著差异,但与DHEA相关的变化仅在血清磷脂(PL)以及肝脏PL和甘油三酯组分中观察到。血清FFA水平的轻微但显著降低可能反映在血清PL FA谱的变化上。肝脏FA谱的特定改变可能与DHEA诱导肝脏过氧化物酶体的已知作用有关。我们推测这种FA变化可能有助于深入了解DHEA的作用机制。