Smart J L, Stephens D N, Tonkiss J, Auestad N S, Edmond J
Br J Nutr. 1984 Sep;52(2):227-37. doi: 10.1079/bjn19840091.
Rat pups were artificially reared (AR) from postnatal day 4 or 5 till day 20 or 21, by fitting them with gastric cannulas through which milk-substitutes could be infused automatically. Three milk-substitutes were compared: milk M, the usual diet for AR studies, which was somewhat low in protein and very high in carbohydrate; milk A, which resembled rats' milk much more closely in composition; and milk isoM, which was based on the high-energy milk M but was made isoenergetic with milk A. Pups given these diets were termed ARM, ARA and ARisoM respectively. Siblings of the AR rats were left with their mothers to form a mother-reared (MR) control group. Rats were autopsied at 20 or 21 d. Growth in body-weight of all groups of AR pups lagged behind that of their MR siblings for about the first week of AR, but the ARM group showed complete catch-up and the ARA group partial catch-up in body-weight during the second week. ARisoM rats were growth-retarded throughout. Inspection of organ weights expressed relative to body-weight revealed disturbances of organ growth in all AR groups compared with MR animals. ARM rats showed excessive epididymal fat pad and liver weights, but deficits in gastrocnemius muscle, heart and adrenal weights. In contrast, ARA rats usually displayed increased spleen and stomach weights, but lower weight of interscapsular brown adipose tissue. ARisoM rats had high brain, liver and stomach weights and low muscle and spleen weights relative to body-weight. All AR groups had elongated small intestines. Hence the patterns of abnormal organ growth differed between groups. Those shown by the ARM and ARisoM groups seemed the more seriously abnormal. The diet approximating the composition of rats' milk (milk A) appears, as intended, to be an improved milk-substitute.
从出生后第4天或第5天开始，给乳鼠安装胃插管，通过胃插管自动输注代乳品，将其人工饲养至第20天或第21天。比较了三种代乳品：代乳品M，是人工饲养研究中常用的饮食，蛋白质含量略低，碳水化合物含量极高；代乳品A，其成分更接近大鼠乳汁；以及等能量代乳品isoM，它以高能量的代乳品M为基础，但能量与代乳品A相当。食用这些饮食的幼崽分别称为ARM、ARA和ARisoM。将人工饲养大鼠的同窝幼崽留给它们的母亲，组成母养（MR）对照组。在第20天或第21天对大鼠进行解剖。在人工饲养的第一周左右，所有人工饲养幼崽组的体重增长都落后于它们的母养同窝幼崽，但ARM组在第二周体重完全追赶上来，ARA组部分追赶上来。ARisoM大鼠在整个过程中生长迟缓。相对于体重检查器官重量发现，与母养动物相比，所有人工饲养组的器官生长都受到干扰。ARM大鼠附睾脂肪垫和肝脏重量过大，但腓肠肌、心脏和肾上腺重量不足。相比之下，ARA大鼠通常脾脏和胃重量增加，但肩胛间棕色脂肪组织重量较低。相对于体重，ARisoM大鼠脑、肝脏和胃重量较高，肌肉和脾脏重量较低。所有人工饲养组的小肠都伸长了。因此，不同组之间器官生长异常的模式不同。ARM组和ARisoM组表现出的异常似乎更为严重。接近大鼠乳汁成分的饮食（代乳品A）似乎如预期的那样，是一种改良的代乳品。
