弓形虫感染妊娠中期BALB/c小鼠对胎鼠生长发育及胎盘系数的影响

目的 探讨弓形虫感染妊娠中期BALB/c小鼠对胎鼠生长发育以及胎盘系数的影响.方法在妊娠第8天采用腹腔注射法建立弓形虫感染的动物模型,于妊娠第12、14、16、18天分批处死孕鼠,分离胎盘胎鼠,解剖显微镜下观察胎鼠存活情况,电子天平称量胎盘和胎鼠重量,游标卡尺测量胎鼠体长和尾长. 结果 随着妊娠天数的增加,实验组孕鼠吸收胎明显增多,出现死胎和流产,正常对照组未见异常;正常对照组胎鼠重量、体长和尾长增加明显(胎鼠重量:40.69±11.63,173.43±30.19,495.56±73.97,967.62±83.34:体长:11.53±0.95,16.83±1.15,20.86±1.25;尾长:5.26±0.56,8.08±0.98,10.54±0.58),胎盘重量呈现先增后减趋势(48.62±11.87,87.14±14.05,94.44±12.29,93.33±13.00),胎盘系数呈降低趋势(1.30±0.52,0.51±0.09,0.20±0.05,0.10±0.02),实验组变化趋势不及正常对照组的明显(胎鼠重量:51.11±13.89,148.16 ±36.09,296.11±58.63;体长:11.51±1.42,14.04±1.59;尾长:4.04±0.95,6.87±0.87;胎盘重量:49.31±9.42,66.41±13.28,52.22±12.15;胎盘系数:1.03±0.32,0.48±0.15,0.18±0.05),组内比较差异均有统计学意义(P<0.05);相同时间点的比较显示除第12天组的胎盘胎鼠重量、第14和16天的胎盘系数,还有第14天的胎鼠体长外,其他数据实验组均低于正常对照组,差异有统计学意义(P<0.05). 结论 弓形虫感染妊娠中期BALB/c小鼠可导致胎盘功能障碍,胎鼠生长发育受限,且随着感染天数的增加,可出现死胎和流产等病理性妊娠.

Effect of Toxoplasma gondii infection on the fetus and placental coefficient of BALB/c mice during the second trimester of pregnancy

Objective To investigate the effect on the growth and development of fetus and placental coefficient of BALB/c mice infected with Toxoplasma gondii during the second trimester of pregnancy. Me-thods The animal model was established by intraperitoneal injection ( i. p. ) of tachyzoites of T. gondii at the 8th day of pregnancy, then the placentas and fetuses of the infected mice were separated at the 12th, 14th,16th, 18th day of pregnancy, respectively. The survival rate of fetus was observed under anatomical micro-scope, the placentas and fetuses were weighted with electronic balance, and the body length and tail length were measured with sliding caliper. Results It was showed that the number of absorbed fetuses increased appar-ently along with the pregnant days in the experimental group, of which the death of fetus and abortion were more than that in the normal control group. In the normal control group, the weight, body length and tail length of fe-tus increased obviously and the placental weight increased at first then decreased afterward, causing a decreased placental coefficient ( weight of fetuses : 40.69 ± 11.63, 173.43 ± 30.19,495.56± 73.97, 967.62 ± 83.34,body length of fetus: 11.53±0.95, 16.83 ±1.15, 20.86 ±1.25, tail length of fetus: 5.26±0.56, 8.08 ±0.98, 10.54 ± 0.58, weight of placentas : 48.62 ±11.87, 87.14 ± 14.05, 94.44 ± 12.29, 93.33 ± 13.00,placental coefficient : 1.30 ± 0.52, 0.51 ± 0.09, 0.20 ± 0.05, 0.10 ± 0.02 ). However, the changes of fetu-ses and placentas in the experimental group were not obvious compared with that in the normal control group ( weight of fetuses: 51.11 ± 13.89, 148.16± 36.09, 296.11 ± 58.63, body length of fetus: 11.51±1.42,14.04 ±1.59, tail length of fetus : 4.04 ±0.95, 6.87 ±0.87, weight of placentas: 49.31 ± 9.42, 66.41 ±13.28, 52.22 ± 12.15, placental coefficient: 1.03 ± 0. 32, 0.48 ± 0.15, 0.18 ±0.05). At the same timepoints, the parameters detected in the experimental group except the weight of the placentas on the 12th day,the placental coefficient on the 14th and 16th day and the body length of fetuses on the 14th day, were signifi-cantly lower than that in the normal control group (P < 0.05). Conclusion The infection of T. gondii dur-ing the second trimester of pregnancy could interfere with placental function and inhibit the growth and develop-ment of the fetus, and may lead to the death of fetus or abortion.