肥胖和體脂肪堆積已被公認與許多疾病和癌症有關，而藉由飲食
控制或運動?減輕體重是目前認為減少肥胖和控制體重最有效的方
法。然而抽脂手術亦被視為是控制體重的另外一種選擇。抽脂所造成
的身體能?儲存的突然短缺會導致代謝重整。?床研究顯示抽脂後的
婦?會在?個月內?胖，而這種代償性的脂肪增長亦在動物實驗中得
到證實。為??解脂肪?除對能?代謝的影響，本研究針對高脂高膽
固醇飲食誘發的肥胖?鼠進?局部脂肪?除手術，再定?分析相關的
肝臟基因和轉?因子的表現，觀察?脂後能?代謝的轉變。
在實驗期間經過局部脂肪?除的大鼠其食物攝取?和對照組之
間無顯著差?。在手術十天後，局部脂肪?除的大鼠體內顯示有較高
的三酸甘油酯，血?和胰島素濃?，與較低濃?的脂肪激素
(Adiponectin)﹔同時，肝臟中?與脂肪新生作用、膽固醇合成作用和
醣質新生作用的相關酵素和肝細胞核內因子4α (HNF4α)的mRNA 濃
?也有顯著增加。透過免疫組織化學分析也證實局部脂肪?除的大鼠
其肝臟組織內有較高濃?的脂肪生成酵素。局部脂肪?除的大鼠體內
有較低的脂肪激素/瘦體素比?(Adiponectin/leptin ratio)，其?值與低密?脂蛋白的濃?呈現正相關（r = 0.823, P< 0.05），與血?和胰島素濃?呈現負相關（r = -0.821 和分別-0.892, P< 0.05）。手術八週後，局部脂肪?除的大鼠其體重和肝臟重?皆增加，肝臟與體重比?也隨之上升，同時體內有較高的三酸甘油酯和胰島素濃?。
綜合上述實驗結果發現，局部脂肪?除的大鼠為?應對脂肪?除
手術所帶?的急速能?儲存變化，會增加肝臟?與脂?和醣?合成代
謝基因的表現，最終導致額外的體重增加。而這些代謝的變化可能是
因為血中脂肪激素濃??低，其進一步影響胰島素和肝臟HNF4α的
作用的結果。
Obesity and body fat deposition are well recognized to be
associated with many diseases and cancer. Diet-induced or
exercise-induced weight loss is therefore considered to be the most effective means to reduce obesity and control weight. However, the esthetic surgery of liposuction has been considered another option for weight control. A sudden shortage of energy storage caused by liposuction might lead to a reprogrammed metabolism. Clinical studies demonstrated that women undergoing liposuction regained fat within six months. This compensatory fat growth was confirmed in several animal models. In order to understand the molecular basis of the impact of lipectomy on energy metabolism, we performed a surgical partial fat removal on high fat and high cholesterol-induced
obese rats, and analyzed quantitatively the hepatic gene
expression and transcription factors involved.
No significant difference was observed on the food intake
between the lipectomized and sham-operated groups during the experimental period. Ten days after the operation, the lipectomized animals showed significant higher triacylglycerol, glucose and insulin levels, a lower adiponectin concentration than the sham-operated rats, along with significant higher hepatic mRNA levels of hepatocyte nuclear factor 4α (HNF4α) and the enzymes involved in lipogenesis, sterol biosynthesis and
gluconeogenesis. The results of immunohistochemical (IHC)
analysis also confirmed increased levels of lipogenic enzymes in the liver of lipectomized versus sham-operated animals. The lipectomized group had a significantly lower adiponectin/leptin ratio that was positively correlated to the level of LDL (r = 0.823, P<0.05) and negatively to glucoseand insulin (r =-0.821 and -0.892 respectively, P<0.05). Eight weeks after the operation, the lipectomized animals revealed significant higher
body and liver weights, weight gain, liver to body weight ratio, hepatic triacylglycerol and serum insulin level.
In response to lipectomy a short term enhancement of the
expression of hepatic anabolic genes involved in lipid and carbohydrate metabolism was triggered that might eventually lead to the final extra weight gain. These metabolic changes could be the results of reduced circulating adiponectin that further influences the functions of insulin and hepatic HNF4α.
