Ohta Y, Iguchi T, Takasugi N
Department of Biology, School of General Education, Tottori University, Japan.
Reprod Toxicol. 1989;3(3):207-12. doi: 10.1016/0890-6238(89)90009-9.
Female rats of the T strain were given single daily injections of 100 micrograms and 200 micrograms of tamoxifen (Tx) and MER-25 (MER) for 5 days beginning on the day of birth (DAY 1). When sacrificed on Day 60, the Tx-treated rats (Tx rats) exhibited continued vaginal diestrus, whereas the females given MER or the vehicle alone showed regular estrous cycles. Ovaries from Tx rats were polyfollicular without corpora lutea, while those from MER rats, as well as from the controls given the vehicle alone, invariably contained both follicles and corpora lutea. In Tx rats, the uteri underwent atrophy, containing few uterine glands in an endometrium largely occupied by fibroblasts. Decidual response of the uterus to intraluminal oil instillation was markedly reduced in Tx rats given an appropriate regimen of progesterone and estradiol injections following ovariectomy on Day 60. By contrast, MER given neonatally had little effects on decidualization. Since ovariectomy on Day 10 brought about no amelioration of the decidualization in Tx rats, it is suggested that the lowered deciduogenic responsiveness to the instillation was caused by a direct action of Tx on the uterus of neonatal rats rather than by a Tx-induced alteration of hypothalamo-hypophyseal-ovarian system. Differences in effect on the female reproductive system between Tx and MER were discussed.
从出生日（第1天）开始，对T品系雌性大鼠每日单次注射100微克和200微克他莫昔芬（Tx）以及MER - 25（MER），持续5天。在第60天处死时，经Tx处理的大鼠（Tx大鼠）呈现持续的阴道间情期，而给予MER或仅给予赋形剂的雌性大鼠表现出规律的发情周期。Tx大鼠的卵巢有多卵泡且无黄体，而MER大鼠以及仅给予赋形剂的对照大鼠的卵巢总是同时含有卵泡和黄体。在Tx大鼠中，子宫发生萎缩，子宫内膜中子宫腺很少，大部分被成纤维细胞占据。在第60天卵巢切除后给予适当的孕酮和雌二醇注射方案，Tx大鼠子宫对宫腔内注入油的蜕膜反应明显降低。相比之下，新生期给予MER对蜕膜化几乎没有影响。由于在第10天进行卵巢切除并未改善Tx大鼠的蜕膜化，提示对注入的蜕膜反应性降低是由Tx对新生大鼠子宫的直接作用引起的，而非由Tx诱导的下丘脑 - 垂体 - 卵巢系统改变所致。讨论了Tx和MER对雌性生殖系统影响的差异。
