Herbert D C
Anat Rec. 1980 Jul;197(3):339-54. doi: 10.1002/ar.1091970308.
A condition of protein-calorie malnutrition was precipitated in young Sprague-Dawley male rats at 20 days of age using an 8% low protein diet (LPD). At five-day intervals for up to 50 days of age, the rats were studied to determine the effect of an LPD on the reproductive axis of the endocrine system. Daily monitoring of the body weight, as well as the consumption of food, kilocalories, and protein was conducted. The same parameters were followed over the identical time period in a group of animals desigated as controls which were fed a standard laboratory diet (SLD) containing 27% protein. The controls showed a linear growth rate over the 30-day experimental period. In comparison, the malnourished rats grew more slowly so that by 50 days of age, their mean body weight was 68.9 +/- 3.1 g as compared to 248.1 +/- 6.1 g for the controls. The daily food, kilocalorie, and protein intake by the experimental animals were also appreciably less. The pituitary gland, ventral prostate gland, testes and liver were smaller in the animals fed the LPD. This was observed as early as five days after initiating the dietary regimes and remained a consistent observation until the end of the experiment. In general, the absolute weights of these organs in the 50 day-old malnourished rats were similar to those found in 25 to 26-day-old animals fed the SLD. The relative weights of the pituitary gland and liver remained similar between the two animal groups. The testes and ventral prostate gland, however, were relatively smaller in the malnourished animals at nearly every time interval studied. On light microscopic examination of the testes, it was found that normal maturation of the germ cells failed to occur in all but one of the experimental animals, whereas maturation proceeded normally in the rats fed the SLD. Serum luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL), and testosterone were lower in the malnourished animals at all ages studied. These hormones not exhibit the fluctuations that were seen in the controls and are typical in rats that are becoming sexually mature. The effect of protein deficiency on the concentration of the pituitary gonadotrophins was more varied. FSH concentrations were consistently lower, PRL was moderately affected, and LH remained essentially unchanged. Hypothalamic LH-releasing hormone was measured and found to be significantly less in the rats fed the LPD at most of the time intervals examined. These results indicate that the hypothalamo-hypophyseal-gonadal axis is impaired when the consumption of proteins and calorie is decreased. The possible involvement of extrahypothlamic centers in the control of hormone secretion in the protein-deficient rat is discussed.
采用8%低蛋白饮食（LPD），使20日龄的幼年斯普拉格-道利雄性大鼠出现蛋白质-热量营养不良状况。在长达50日龄期间，每隔5天对这些大鼠进行研究，以确定低蛋白饮食对内分泌系统生殖轴的影响。每天监测体重以及食物、千卡和蛋白质的摄入量。在同一时间段内，对一组喂食含27%蛋白质的标准实验室饮食（SLD）的动物（ designated as controls 原文有误，应是designated as controls ，意为“ designated as controls”）进行相同参数的跟踪监测。对照组在30天的实验期内呈现线性生长速率。相比之下，营养不良的大鼠生长较慢，到50日龄时，它们的平均体重为68.9±3.1克，而对照组为248.1±6.1克。实验动物的每日食物、千卡和蛋白质摄入量也明显较少。喂食低蛋白饮食的动物的垂体、腹侧前列腺、睾丸和肝脏较小。早在开始饮食方案5天后就观察到这种情况，并且一直持续到实验结束。一般来说，50日龄营养不良大鼠这些器官的绝对重量与喂食标准实验室饮食的25至26日龄动物的相似。两组动物垂体和肝脏的相对重量保持相似。然而，在几乎每个研究的时间间隔，营养不良动物的睾丸和腹侧前列腺相对较小。对睾丸进行光镜检查发现，除一只实验动物外，所有实验动物的生殖细胞均未正常成熟，而喂食标准实验室饮食的大鼠生殖细胞成熟正常。在所有研究年龄段，营养不良动物的血清促黄体生成素（LH）、促卵泡生成素（FSH）、催乳素（PRL）和睾酮水平均较低。这些激素未表现出对照组中所见的波动，而这种波动在性成熟大鼠中是典型的。蛋白质缺乏对垂体促性腺激素浓度的影响更为多样。促卵泡生成素浓度持续较低，催乳素受到中度影响，促黄体生成素基本保持不变。测量下丘脑促黄体生成素释放激素，发现在大多数检查的时间间隔，喂食低蛋白饮食的大鼠该激素水平显著较低。这些结果表明，当蛋白质和热量摄入减少时，下丘脑-垂体-性腺轴受损。讨论了下丘脑外中枢在蛋白质缺乏大鼠激素分泌控制中的可能作用。
