EFFECTS OF NICOTINE ON EARLY-PREGNANCY IN THE RAT
EFFECTS OF NICOTINE ON EARLY-PREGNANCY IN THE RAT
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DOI：
10.1095/biolreprod20.2.294
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发表时间：
1979-01-01
影响因子：
3.6
通讯作者：
PILOT, RL
中科院分区：
文献类型：
--
作者：
YOSHINAGA, K;RICE, C;PILOT, RL
研究了尼古丁对大鼠植入前胚胎发育的影响。皮下注射高剂量尼古丁（7.5 毫克酒石酸尼古丁）。从发情前期早上（怀孕第 0 天）到处死当天，每天两次。在妊娠第1-5天的600、1200、1800或2400小时处死大鼠，记录卵子的位置和发育阶段。尼古丁导致延迟 .apprx。卵子从 2 细胞到 4 细胞阶段分裂 12 小时。 4细胞阶段之后胚胎发育的每一步都因此被延迟。在接受尼古丁治疗的大鼠中，卵子进入子宫、囊胚形成、透明带脱落和植入均被延迟。在怀孕第3天单次注射0.2μg雌二醇消除了卵子进入子宫的延迟。每天注射尼古丁会导致子宫角输卵管末端的植入部位集中或拥挤。第 4 天下午额外注射雌激素导致更严重的拥挤。植入前期间，尼古丁治疗的大鼠外周血清中黄体酮（P）、黄体生成素（LH）和催乳素（PRL）的浓度低于盐水治疗的大鼠。与生理盐水处理的大鼠相比，尼古丁处理的大鼠的雌激素和卵泡刺激素的血清浓度较高。经尼古丁处理的大鼠卵子着床延迟并非由于分泌或雌激素减少，而是由于磷分泌增加延迟，而磷分泌是子宫准备植入胚泡所必需的。这种 P 分泌紊乱似乎至少部分是尼古丁治疗引起的下丘脑-垂体轴激素失衡的结果。
The effects of nicotine on preimplantation embryonic development were investigated in the rat. A high dose of nicotine (7.5 mg nicotine tartrate) was injected s.c. twice daily from the morning of proestrus (day 0 of pregnancy) until the day of sacrifice. Rats were sacrificed at 600, 1200, 1800 or 2400 h on days 1-5 of pregnancy and the location and stage of development of the ova were recorded. Nicotine caused a delay of .apprx. 12 h in ovum cleavage from the 2-cell-4-cell stage. Each step of embryonic development after the 4-cell stage was thereby delayed. In nicotine-treated rats, ovum entry into the uterus, blastocyst formation, shedding of the zona pellucida and implantation were delayed. A single injection of 0.2 .mu.g estradiol on day 3 of pregnancy abolished the delay in ovum entry into the uterus. Daily injection of nicotine caused a concentration or crowding implantation sites toward the tubal ends of the uterine horns. An additional injection of estrogen on the afternoon of day 4 resulted in even greater crowding. Concentrations of progesterone (P), luteinizing hormone (LH) and prolactin (PRL) in peripheral serum during the preimplantation period were lower in nicotine-treated rats than in saline-treated rats. Serum concentrations of estrogens and follicle stimulating hormone were higher in nicotine-treated rats as compared to those in saline-treated rats. Delayed implantation of ova in nicotine-treated rats is due not to a decreased secretion or estrogen, but rather to a delay in the increase of P secretion which is necessary to prepare the uterus for implanting blastocysts. This disturbance in P secretion appears to be the result, at least in part, of the hormonal imbalance of the hypothalamo-pituitary axis caused by the nicotine treatment.