Objective To investigate lead distribution and the change of 78 000 glucose regulated protein ( GRP78 ) in various organs of weaned rats challenged with low-level maternal origin lead. Methods Male littermates, bred from the female Fisher 344 rats gavaged with lead acetate or sodium acetate ( 1 ml of 10 mg/ml per day per animal) with male Fisher 344 rats without lead treatment, were divided into 4 groups including control ( group A), gestation plus lactation ( group B ), gestation only ( group C), and lactation only ( group D). Each group had 6 liners. These littermates were weaned and terminated at postnatal day 21. Lead contents and GRP78 levels in various organs of these littermates were determined by atomic absorbanee spectrometry (AAS) and Western blotting analysis, respectively. Results Maternal lead was observed to transfer to littermates through gestation and lactation. Concentrations of littermate blood lead in groups A to D were(0.0010 ±0.0010), (0.1420 ±0.0190), (0.0250 ±0.0040) ,and(0.1490 ±0.0160) μg/ml, respectively. Concentrations of littermate brain lead in groups A to D were (0.0005 ± 0.0005 ), (0. 1120 ±0.0130 ), (0.0125 ± 0.0042 ), and ( 0.0700 ± 0. 0058 ) μg/g, respectively. Concentrations of littermate kidney lead in groups A to D were(0.0050 ±0.0050), ( 1.0400 ±0.1000), (0.1040 ±0.0330), and (0. 9920 ±0. 0850) μg/g, respectively. Concentrations of littermate liver lead in groups A to D were (0. 0030 ± 0.0050 ), ( 0.3600 ± 0.0550 ), (0.0567 ± 0.0126 ), and (0. 3030 ± 0.0310 ) μg/g, respectively. Blood, brain, kidney and liver lead concentrations in groups B and D were significantly higher than those in group C and differences were 5-10 folds. Arbitrary units of littermate leukocytic GRP78 concentration normalized with actin protein in groups A to D were 1. 000 ~0. 038, 1. 180 ±0. 060, 0.998 ± 0. 109, and 1. 290 ±0. 110, respectively. Arbitrary units of littermate brain GRP78 concentration normalized with aetin protein level in groups A to D were 0. 996 ±0. 128, 0.922 ± 0. 246, 1. 150 ±0. 170, and 0. 750 ~0. 126, respectively. Conclusion Lead in maternal bodies could be transferred to Utter bodies through gestation and lactation and distributed in various organs. Lead might also changed GRP78 expression in leukocytes.%目的 研究母源性铅在断乳期仔鼠不同器官中的分布和其对相对分子质量为78 000糖调蛋白(GRP78)的影响.方法 取8只成年Fisher 344雌性大鼠,按完全随机方法分为对照组和染铅组,每组4只.染铅组母鼠从交配前30 d起每天被强饲l ml(10 mg/ml)乙酸铅溶液,对照组母鼠给予l ml(10 mg/ml)乙酸钠溶液.两组母鼠饲养30 d后,按雌雄2:1合笼.根据母源性受铅的不同途径,自然分娩后的雄性仔鼠被分成4组,每组6只.A组,仔鼠产自对照组母鼠,并一直由对照组母鼠哺乳到断乳时(出生后21 d);B组,仔鼠产自染铅组母鼠,并一直由染铅组母鼠哺乳到断乳时;C组,仔鼠产自染铅组母鼠,但由对照组母鼠哺乳到断乳时;D组,仔鼠产自对照组母鼠,但由染铅组母鼠哺乳到断乳时.用原子吸收分光光度法和Western blotting方法分别测定断乳期仔鼠不同器官中的铅和GRP78的变化.结果 母鼠体内的铅可以通过妊娠和哺乳途径传给仔鼠.A、B、C、D组仔鼠血铅浓度分别为(0.0010±0.0010)、(0.1420±0.0190)、(0.0250±0.0040)、(0.1490±0.0160)μg/ml,A、B、C、D组仔鼠脑铅浓度分别为(0.0005±0.0005)、(0.1120±0.0130)、(0.0125±0.0042)、(0.0700±0.0058)μg/g,A、B、C、D组仔鼠肾脏铅浓度分别为(0.0050±0.0050)、(1.0400 ±1000)、(0.1040±0.0330)、(0.9920±0.0850)μg/g,A、B、C、D组仔鼠肝脏铅浓度分别为(0.0030±0.0050)、(0.3600±0.0550)、(0.0567±0.0126)、(0.3030±0.0310)μg/g.B组和D组的血铅、脑铅、肾脏铅及肝脏铅浓度是C组的5～10倍.A、B、C、D组仔鼠白细胞GRP78相对灰度值分别为1.000±0.038、1.180±0.060、0.998±0.109、1.290±0.110,A、B、C、D组仔鼠大脑GRP78相对灰度值分别为0.996±0.128、0.922±0.246、1.150 ±0.170、0.750±0.126.结论 母鼠体内的铅可以通过妊娠和哺乳输送到仔鼠的不同器官中,改变白细胞GRP78的表达.
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