Loctin J, Delost P
Reprod Nutr Dev (1980). 1983;23(5):915-26. doi: 10.1051/rnd:19830612.
This paper reports a statistical and transversal study of growth in about 2400 surviving premature mice during neonatal development. The mice were removed by caesarean section on day 19 of pregnancy and resuscitated for 30 min; surviving mice as well as newborns delivered vaginally on day 20 (control mice) were raised from birth to day 20 by nursing mothers spontaneously delivered at the same time. Only litters from nursing dams which suckled newborns regularly were used in the statistical study. Somatic development in the premature mice and newborn controls was estimated by changes in body weight and in the weight of several organs (liver, kidney, adrenal glands) after the newborns had been killed at five developmental stages: 30 min after reanimation or parturition, 6 h after birth and at 9 h on days 2, 6 and 20. Growth was analysed by growth curves, percentage of weight gain per day, regression lines and allometric lines; weight gain was calculated as a function of the number of newborns per litter. The low birth weight of live premature mice affected body weight and kidney and adrenal weights. After an early, transitory loss of body and organ weights, which occurred d ring the first neonatal day, the weight handicaps of premature mice were overcome before neonatal day 20 as follows: adrenal weight between 6 h and day 2, liver weight between days 2 and 6, kidney and body weights between days 6 and 20. Throughout these stages, the weight gain of body and organs was higher than that of full-term newborns. The weight gains of premature mice, like those of full-term newborns, were in inverse ratio to the number of newborns per litter. The role of some factors involved in the growth of organs of premature mice has been discussed and the somatic development of surviving premature mice has been compared to that of smallest premature human infants.
本文报告了一项关于约2400只存活的早产小鼠在新生儿发育期间生长情况的统计及横向研究。这些小鼠在妊娠第19天通过剖腹产取出并复苏30分钟；存活的小鼠以及在第20天经阴道分娩的新生儿（对照小鼠）由同时自然分娩的哺乳母亲从出生饲养至第20天。统计研究仅使用定期哺乳新生小鼠的哺乳母鼠所产的窝。在五个发育阶段处死新生小鼠后，通过体重及几个器官（肝脏、肾脏、肾上腺）重量的变化来评估早产小鼠和新生对照的躯体发育，这五个阶段分别为：复苏或分娩后30分钟、出生后6小时以及出生后第2天、第6天和第20天的9小时。通过生长曲线、每日体重增加百分比、回归线和异速生长线分析生长情况；体重增加量作为每窝新生小鼠数量的函数进行计算。存活的早产小鼠出生体重低影响了体重以及肾脏和肾上腺的重量。在出生后第一天出现早期短暂的体重和器官重量下降后，早产小鼠的体重劣势在出生后第20天前得到克服，具体如下：肾上腺重量在6小时至第2天之间恢复，肝脏重量在第2天至第6天之间恢复，肾脏和体重在第6天至第20天之间恢复。在这些阶段中，身体和器官的体重增加高于足月新生儿。早产小鼠的体重增加与足月新生儿一样，与每窝新生小鼠数量成反比。本文讨论了一些与早产小鼠器官生长有关的因素的作用，并将存活的早产小鼠的躯体发育与最小的早产人类婴儿的躯体发育进行了比较。
