Bellinger L L, Castonguay T W, Bernardis L L
Department of Biomedical Sciences, Baylor College of Dentistry, Dallas, TX 75246.
Brain Res Bull. 1994;34(2):117-24. doi: 10.1016/0361-9230(94)90007-8.
Rats with dorsomedial hypothalamic nuclei lesions (DMNL) are hypophagic and have reduced linear and ponderal growth, but have normal body composition and anabolic hormone concentrations. Previous studies have shown rats pair-fed to levels consumed (70-80% of ad lib) by DMNL rats, using a meal-feeding paradigm, have abnormal body composition and hormone concentrations. Whether the noted changes were due to restriction per se or method of food presentation was uncertain. In the present study, one group of sham-operated rats was pair fed (SHPF) by a computer-operated system that presented 45 mg food pellets in the exact amount and pattern as their DMNL yoked partner; another sham-operated group was ad lib fed (SHAD). At the end of Experiment 1 (11 days) and Experiment 2 (3 weeks) blood was collected for hormone and metabolite analyses; body compositions were also determined. Unlike an earlier report, the DMNL and SHPF groups had normal percentage body fat. Percentage carcass protein was similar in all groups at 11 days, but slightly elevated in DMNL rats at 3 weeks. Also, in contrast to an earlier study, plasma-free fatty acid levels were comparable in DMNL and SHPF rats. Plasma insulin was normal in the DMNL and SHPF rats at 11 days, but was lowered (p < 0.05) in the SHPF group at 3 weeks. Plasma thyroxine was reduced (p < 0.01) in the SHPF group at 11 days but returned to normal by 3 weeks. Thyroxine and triiodothyronine levels were normal in the DMNL groups. Plasma corticosterone levels were similar in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)
患有下丘脑背内侧核损伤（DMNL）的大鼠摄食量减少，线性生长和体重增加减缓，但身体成分和合成代谢激素浓度正常。先前的研究表明，采用餐饲模式将成对喂养的大鼠的摄入量控制在DMNL大鼠所消耗水平（自由摄食量的70 - 80%）时，它们的身体成分和激素浓度会异常。尚不确定所观察到的变化是由于摄食限制本身还是食物呈现方式所致。在本研究中，一组假手术大鼠由计算机操作系统成对喂养（SHPF），该系统以与它们的DMNL配对伙伴完全相同的量和模式提供45毫克食物颗粒；另一组假手术大鼠自由进食（SHAD）。在实验1（11天）和实验2（3周）结束时，采集血液进行激素和代谢物分析；同时也测定身体成分。与早期报告不同，DMNL组和SHPF组的体脂百分比正常。在11天时，所有组的胴体蛋白质百分比相似，但在3周时DMNL大鼠的该指标略有升高。此外，与早期研究相反，DMNL大鼠和SHPF大鼠的血浆游离脂肪酸水平相当。在11天时，DMNL大鼠和SHPF大鼠的血浆胰岛素水平正常，但在3周时SHPF组的血浆胰岛素水平降低（p < 0.05）。在11天时，SHPF组的血浆甲状腺素降低（p < 0.01），但在3周时恢复正常。DMNL组的甲状腺素和三碘甲状腺原氨酸水平正常。所有组的血浆皮质酮水平相似。（摘要截取自250字）
