Takeo Y, Shirama K, Shimizu K, Maekawa K
Endocrinol Jpn. 1975 Oct;22(5):453-6. doi: 10.1507/endocrj1954.22.453.
The rats brought up under continuous illumination from the neonatal day persist in the rhythmic estrous cycle for long time and do not easily reveal so-called continuous vaginal estrus. On the contrary, immature rats at about 30 days of age show the persistent estrus soon after exposure to continuous illumination as well as adult rats. The purpose of this paper was to examine the relation of the age placed under continuous illumination and the time required to reach the persistent estrus. As the results, it was found that the younger rats need proportionally the longer time to reach the persistent estrus; the rats which were transferred into continuously illuminated environment at 0 (group A), 5 (group B), 10 (group C), 15-16 (group D) and 30 (group E) days of age required a mean time of 132.1 +/- 8.4, 126.8 +/- 8.9, 89.7 +/- 6.2, 91.5 +/- 3.8 and 70.3 +/- 3.0 days after birth to reach the persistent estrus, respectively. In the present data, a significant difference was seen between group B and C. Though all rats were killed after the same length of persistently estrous periods, actual endocrine level appeared to differ among the groups; the rats required longer time to reach the persistent estrus had smaller ovaries and adrenals.
从新生期开始持续光照饲养的大鼠，其发情周期的节律会持续很长时间，且不容易出现所谓的持续性阴道发情。相反，大约30日龄的未成熟大鼠在暴露于持续光照后，与成年大鼠一样很快就会出现持续性发情。本文的目的是研究持续光照时的年龄与达到持续性发情所需时间之间的关系。结果发现，年龄越小的大鼠达到持续性发情所需的时间成比例地越长；在0（A组）、5（B组）、10（C组）、15 - 16（D组）和30（E组）日龄转入持续光照环境的大鼠，分别在出生后平均132.1±8.4、126.8±8.9、89.7±6.2、91.5±3.8和70.3±3.0天达到持续性发情。在本数据中，B组和C组之间存在显著差异。尽管所有大鼠在相同长度的持续性发情期后被处死，但各实验组实际的内分泌水平似乎有所不同；达到持续性发情所需时间较长的大鼠，其卵巢和肾上腺较小。
