Mordes J P, Longcope C, Flatt J P, MacLean D B, Rossini A A
Endocrinology. 1984 Jul;115(1):167-73. doi: 10.1210/endo-115-1-167.
Anorexia occurs in male rats bearing transplantable LTW(m) Leydig cell tumors. Previous studies had shown that this tumor caused decreased food consumption and weight loss within 2 weeks of implantation. Additional studies reported here demonstrate that this tumor had little anorectic effect in female rats, and that male rats with LTW(m) tumors had elevated concentrations of circulating estradiol and low levels of testosterone. The tumor was also anorexigenic in castrated male rats. Exogenous estrogen given in the form of sc implanted pellets of estradiol reduced weight gain in male rats in proportion to the dose of estradiol. Weight gain was reduced when the plasma estradiol concentration was as low as 49 +/- 3 pg/ml; control estradiol levels were 25 +/- 4 pg/ml. Similar effects were observed in male Zucker fatty rats. It was further demonstrated that the tumor is anorexigenic in ventromedial hypothalamus-lesioned rats, an effect previously observed in ventromedial hypothalamus-lesioned rats given exogenous estradiol. Carcass analysis revealed that tumor-bearing rats used a metabolic fuel mixture containing a higher percentage of fat-derived substrates compared to nonimplanted controls, suggesting that altered fuel utilization may contribute to the decreased weight gain of tumor-bearing rats. We conclude that the circulating substance responsible for LTW(m) tumor-induced anorexia in male rats is likely to be an estrogenic steroid.
厌食症发生在携带可移植LTW(m) 间质细胞瘤的雄性大鼠身上。先前的研究表明，这种肿瘤在植入后2周内会导致食物摄入量减少和体重减轻。此处报告的其他研究表明，这种肿瘤对雌性大鼠几乎没有厌食作用，并且患有LTW(m) 肿瘤的雄性大鼠循环雌二醇浓度升高而睾酮水平较低。该肿瘤对去势雄性大鼠也有厌食作用。以皮下植入雌二醇丸剂形式给予的外源性雌激素会使雄性大鼠的体重增加按雌二醇剂量成比例减少。当血浆雌二醇浓度低至49±3 pg/ml时体重增加减少；对照雌二醇水平为25±4 pg/ml。在雄性 Zucker 肥胖大鼠中也观察到了类似的效果。进一步证明，该肿瘤对腹内侧下丘脑损伤的大鼠有厌食作用，这一作用先前在给予外源性雌二醇的腹内侧下丘脑损伤大鼠中也观察到。胴体分析显示，与未植入的对照相比，携带肿瘤的大鼠使用的代谢燃料混合物中脂肪衍生底物的百分比更高，这表明燃料利用的改变可能导致携带肿瘤大鼠体重增加减少。我们得出结论，导致雄性大鼠LTW(m) 肿瘤诱导厌食症的循环物质可能是一种雌激素类固醇。
