Bernardis L L
Brain Res Bull. 1985 Jun;14(6):537-49. doi: 10.1016/0361-9230(85)90103-0.
This report juxtaposes findings from weanling rats with precise lesions in the ventromedial (VMNL rats) to data of weanling rats with lesions in the dorsomedial (DMNL) hypothalamic nuclei. Despite the proximity of the two nuclei their destruction produces opposite effects in most cases but similar responses in other parameters. Absolute and relative food intake are normal in VMNL rats yet they become obese in the face of normal body weight gains. DMNL rats show both reduced absolute food intake and body weight but normal relative food intake and body composition. Both VMNL and DMNL cause reduced linear growth and running wheel activity. DMNL rats defend their lower body weight set point against various challenges and maintain normal body composition. Organ growth in both absolute and relative terms is reduced in VMNL rats. In DMNL rats relative organ growth is normal. Pancreatic growth, protein/pancreas and content and concentrations of several pancreatic enzymes are normal in DMNL but reduced in VMNL rats. Mean 24-hour plasma growth hormone (GH) and corticosterone (B) levels are reduced and insulin levels are greatly elevated in VMNL rats; prolactin (PRL) levels are normal. In DMNL rats, GH, B, insulin and somatomedin activity are normal but PRL is elevated. Circadian rhythms of GH, insulin and triiodothyronine are normal in DMNL rats but B levels are disrupted, as they are in VMNL rats. Glucose incorporation and oxidation in adipose tissue of VMNL rats are enhanced in VMNL rats but normal in DMNL rats. Gluconeogenesis in VMNL rats is enhanced as early as 4 hours post-operatively; in DMNL rats it is normal at this time and several weeks thereafter. Basal lipolysis in epididymal fat pads is elevated in both VMNL and DMNL rats but epinephrine-stimulated lipolysis is elevated in VMNL and decreased in DMNL rats. Both VMNL and DMNL rats show normal basal and epinephrine-stimulated lipolysis in interscapular brown adipose tissue. Several hepatic enzymes are normal in DMNL and depressed in VMNL rats. The above data suggest that the DMN and its circuitry are part of an "organismic" set point system with a "true" body weight and no fat set point, as seems to be the case in the VMNL rat.
本报告将断奶大鼠腹内侧下丘脑核精确损伤（VMNL大鼠）的研究结果与断奶大鼠背内侧下丘脑核（DMNL）损伤的数据并列呈现。尽管这两个核团位置相近，但在大多数情况下，它们的破坏会产生相反的效应，而在其他参数上则产生相似的反应。VMNL大鼠的绝对和相对食物摄入量正常，但在体重正常增加的情况下却会肥胖。DMNL大鼠的绝对食物摄入量和体重均降低，但相对食物摄入量和身体组成正常。VMNL和DMNL均导致线性生长和转轮活动减少。DMNL大鼠能抵御各种挑战，维持其较低的体重设定点，并保持正常的身体组成。VMNL大鼠的器官绝对和相对生长均减少。DMNL大鼠的相对器官生长正常。DMNL大鼠的胰腺生长、蛋白质/胰腺含量以及几种胰腺酶的浓度正常，而VMNL大鼠则降低。VMNL大鼠的平均24小时血浆生长激素（GH）和皮质酮（B）水平降低，胰岛素水平大幅升高；催乳素（PRL）水平正常。在DMNL大鼠中，GH、B、胰岛素和生长介素活性正常，但PRL升高。DMNL大鼠中GH、胰岛素和三碘甲状腺原氨酸的昼夜节律正常，但B水平紊乱，VMNL大鼠也是如此。VMNL大鼠脂肪组织中的葡萄糖掺入和氧化增强，而DMNL大鼠正常。VMNL大鼠术后4小时即出现糖异生增强；DMNL大鼠此时及此后数周糖异生正常。VMNL和DMNL大鼠附睾脂肪垫的基础脂肪分解均升高，但VMNL大鼠肾上腺素刺激的脂肪分解升高，而DMNL大鼠降低。VMNL和DMNL大鼠肩胛间棕色脂肪组织的基础和肾上腺素刺激的脂肪分解均正常。DMNL大鼠的几种肝酶正常，而VMNL大鼠则降低。上述数据表明，DMN及其神经回路是“机体”设定点系统的一部分，具有“真实”体重设定点，而无脂肪设定点，VMNL大鼠似乎也是如此。
