Ma Hai-yan, Li Hong, Wang Jiao-chen, Liu Xiu-qin, Xu Feng-sen, Tan Jin-shan
Department of Paediatrics, Department of Pathology, Qingdao Municipal Hospital, Qingdao 266011, China.
Zhonghua Yu Fang Yi Xue Za Zhi. 2006 Mar;40(2):101-4.
To investigate the effects of lead exposure to rat placenta and pups during different gestation periods.
All 108 Wistar rats (72 females, 36 males) were randomly divided into four groups. All rats were orally fed with 0.025% lead acetate during different gestation periods. Blood was obtained from the abdominal vena cava and the lead level in maternal blood was measured by means of atomic absorption spectrometry at the end of the pregnancy. The number of pups, their body weight, body length and tail length were measured. The effects of lead to rat placenta were observed by level of microscopy, optical microscopy and electronic microscopy.
Experimental groups the blood lead level at the end of gestation were above 0.483 micromol/L. There were significant differences among, of pups, during different groups (P < 0.01). Among them the drinking lead group of whole distant was the lowest in placenta weight [(0.31 +/- 0.13) g] body weight of pups [(2.08 +/- 0.88) g] length and tail length of pups [(2.37 +/- 0.32) cm, (0.98 +/- 0.09) cm]. There were significantly differences between the experimental groups and controls. Maternal blood lead level was negatively related to placenta weight (r = 0.652, P < 0.01), and had no relation with the body weight of pups (r = -0.107, P = 0.46). In the experimental groups of lead poisoned rats, the placenta showed focus necrosis in the deciduas, and increased the trophoblastic giant cells and light staining cells in the trophospongium. Trophoblast in the labyrinth and trophospongium showed degeneration; fibrin deposition around the villi was increased. Microvilli around the trophoblast were shorter and less, mitochondrion was swollen and decreased in number, rough endoplasmic reticulum was distended and ribosomal number on membrane decreased.
Lead exposure during different gestation periods should have a traumatic effect on the trophoblast, leading to interference of nutrition and oxygen exchange. Furthermore, the blood supply to the placenta and nutrition and oxygen exchange between mother and pups were also interfered, leading to reduction of placenta weight and retardation of development of pups.
研究不同孕期铅暴露对大鼠胎盘及幼崽的影响。
将108只Wistar大鼠（72只雌性，36只雄性）随机分为四组。所有大鼠在不同孕期经口给予0.025%醋酸铅。妊娠末期从腹静脉取血，采用原子吸收光谱法测定母血铅水平。测量幼崽数量、体重、体长和尾长。通过光镜、光学显微镜和电子显微镜观察铅对大鼠胎盘的影响。
实验组妊娠末期血铅水平均高于0.483微摩尔/升。不同组间幼崽数量存在显著差异（P < 0.01）。其中全孕期饮铅组胎盘重量最低[（0.31±0.13）克]，幼崽体重[（2.08±0.88）克]、体长和尾长[（2.37±0.32）厘米，（0.98±0.09）厘米]也最低。实验组与对照组之间存在显著差异。母血铅水平与胎盘重量呈负相关（r = 0.652，P < 0.01），与幼崽体重无相关性（r = -0.107，P = 0.46）。在铅中毒大鼠实验组中，胎盘蜕膜出现局灶性坏死，滋养海绵层中滋养巨细胞和淡染细胞增多。迷路和滋养海绵层中的滋养层出现变性；绒毛周围纤维蛋白沉积增加。滋养层周围微绒毛变短变少，线粒体肿胀且数量减少，粗面内质网扩张，膜上核糖体数量减少。
不同孕期铅暴露对滋养层有损伤作用，导致营养和氧气交换受到干扰。此外，胎盘的血液供应以及母鼠与幼崽之间的营养和氧气交换也受到干扰，导致胎盘重量减轻和幼崽发育迟缓。
