Abstract: Objective To explore the effects of congenital lead exposure on physique indicators and mineral nutrition status in developmental offspring of rats. Methods The animal model of congenital lead exposure was established with the use of similar genetic background Sprague Dawley pregnant rats drinking freely 0.1% (low-dose group,LG) and 0.2% (high-dose group,HG) lead acetate solution.The normal control group (NG) was also established.Dynamic measurement of the weights and the tail lengths were adopted to show the physical growth conditions of the offspring rats on 1 to 7 days (1 to 7 d) and 14 days (14 d) after birth.The levels of plasma lead,zinc,iron,and calcium on 36 d and 60 d,serum growth hormone (GH) were measured through the Methods of atomic absorption spectrometry and radioimmunoassay. Results The average birth weight and tail length of offspring rats decreased in congenital lead exposure groups (P<0.01).Compared to group NG,the growth of weight and tail length on 2 to 14 d was significantly slow in groups LG and HG (P<0.01).As for the levels of plasma zinc and iron,there were significant statistical differences among groups NG,LG and HG on both 36 d and 60 d (P<0.01).On 36 d,the offspring rats' plasma calcium in groups NG[(2.03±0.22) mmol/L],LG[(1.75±0.24) mmol/L] and HG[(1.62±0.21) mmol/L] were significantly different (P<0.01).On 60 d,the plasma calcium levels of groups NG,LG and HG were respectively (2.02±0.21)mmol/L,(1.85±0.22)mmol/L and (1.76±0.17)mmol/L (P<0.01).The serum GH of 60 d offspring rats were (2.15±0.35) ng/ml for NG,(1.98±0.24) ng/ml for LG,and (1.86±0.25) ng/ml for HG (P<0.01).There were also significant statistical differences between HG and NG (P<0.01),LG and NG (P<0.01) or HG and LG (P<0.05). Conclusion Congenital lead exposure can lead to intrauterine growth restriction in fetal rats and physique growth delay in offspring rats after birth,which may be related to decreases of GH secretion and deficiency of mineral nutrient zinc,iron and calcium.

Key words: lead exposure, physique growth, development retardation, embryonic period, growth hormone

摘要： 目的 观察先天性铅暴露对发育期子代大鼠体格发育指标及矿物质水平的影响,分析其损害的特点并初步探讨可能的影响因素。方法 选择遗传背景近似的孕鼠自由饮用0.1%及0.2%醋酸铅溶液的方法建立先天性铅暴露模型,其子代分别为低剂量铅暴露组(LG)及高剂量铅暴露组(HG),同时设立正常对照组(NG)。测量仔鼠生后第1~7天(1~7 d)及14 d的体质量及尾长。36 d及60 d仔鼠应用原子吸收法检测血铅、锌、钙及铁水平。60 d仔鼠应用放射免疫法检测血清生长激素(GH)水平。结果 先天性铅暴露组仔鼠出生时平均体质量与尾长降低(P<0.01)。2~14 d,LG、HG组仔鼠体质量及尾长增长较NG组显著减缓(P<0.01)。NG、LG、HG组36 d及60 d仔鼠血锌、铁水平差异有统计学意义(P<0.01)。36 d时,NG[(2.03±0.22) mmol/L]、LG[(1.75±0.24) mmol/L]、HG[(1.62±0.21) mmol/L]组仔鼠血钙水平差异有统计学意义(P<0.01)。NG、LG、HG组60 d仔鼠血钙分别为(2.02±0.21)、(1.85±0.22)mmol/L及(1.76±0.17)mmol/L(P<0.01)。NG、LG、HG组60 d仔鼠血清GH分别为:(2.15±0.35)、(1.98±0.24)、(1.86±0.25) ng/ml(P<0.01);HG与NG组(P<0.01),LG与NG组(P<0.01)以及HG与LG组间差异有统计学意义(P<0.05)。结论 先天性铅暴露可导致胎鼠宫内发育迟滞及仔鼠体格发育落后,可能与锌、铁、钙等矿物质营养水平降低及GH分泌不足有关。

关键词: 铅暴露, 体格生长, 发育迟滞, 胚胎期, 生长激素