Bosc M J, Nicolle A, Ducelliez D
Reprod Nutr Dev (1980). 1986;26(3):777-89. doi: 10.1051/rnd:19860503.
The temporal relationship between time of birth and daily physical activity has been studied in rats submitted to different feeding rhythms. Animals, put under 14 h of light and 10 h of darkness (lights on from 6 to 20 h), were isolated at mating (day 1 of gestation) and assigned from day 8 to one of five groups. Group C was fed ad libitum, and groups 2PF, 9PF, 14PF and 21PF had food available for three hours per day from 2, 9, 14 and 21 h, respectively. In groups 9PF and 14PF, births were clustered in one single period during the night between days 22 and 23 of gestation. In groups C, 2PF and 21PF, births were distributed into two periods, during the afternoon of day 22 before darkness and after dawn of day 23. The birth rates of these groups were 55.3, 74.2 and 27.6%, respectively, on day 22 and 44.7, 25.8 and 72.4% on day 23. No births occurred during the times that food was available; they were noted in all groups at times when the animals were least active according to records kept throughout gestation. Thus, restricting food availability to periods of normal inactivity (groups 9PF and 14PF vs group C) led to a major shift in the time of delivery as well as to a distortion of the normal activity patterns. These results confirm that feeding rhythms are potent entrainers of birth time in rats and that they interact with the light regime. Pregnant rats seem to be organized so that birth either precedes the main daily physical activity or follows it, depending upon the environmental conditions.
在处于不同喂食节律的大鼠中，研究了出生时间与日常身体活动之间的时间关系。将动物置于14小时光照和10小时黑暗（6至20小时开灯）的环境中，在交配时（妊娠第1天）进行隔离，并从第8天起分为五组。C组自由进食，2PF、9PF、14PF和21PF组每天分别在2、9、14和21时可获得三小时的食物。在9PF组和14PF组中，出生集中在妊娠第22天至23天夜间的一个时间段内。在C组、2PF组和21PF组中，出生分布在两个时间段，分别是第22天下午天黑前和第23天黎明后。这些组在第22天的出生率分别为55.3%、74.2%和27.6%，在第23天分别为44.7%、25.8%和72.4%。在可获得食物的时间段内没有出生情况；根据整个妊娠期的记录，在所有组中，出生都发生在动物最不活跃的时候。因此，将食物供应限制在正常不活动的时间段（9PF组和14PF组与C组相比）导致分娩时间发生重大变化，同时也扭曲了正常的活动模式。这些结果证实，喂食节律是大鼠出生时间的有效同步因素，并且它们与光照制度相互作用。怀孕大鼠似乎有这样的规律，即分娩要么在主要日常身体活动之前，要么在其之后，这取决于环境条件。
