钙对染铅大鼠骨骼TRPV通路中相关基因mRNA表达的影响

EFFECTS OF CALCIUM ON m RNA EXPRESSION OF TRPV PATHWAY RELATED GENES IN LEAD EXPOSURE RATS

目的研究不同剂量钙对染铅大鼠骨骼TRPV通路中相关基因mRNA表达的影响,从分子水平探讨其干预机制,为适量补钙预防铅中毒提供理论依据。方法选用(50±5)g的健康雄性SD大鼠60只,适应性喂养7d后,随机分为五组:对照组(基础饲料,去离子水)、染铅组(基础饲料,0.2%醋酸铅水)、试验Ⅰ组(基础饲料添加0.5%碳酸钙,0.2%醋酸铅水)、试验Ⅱ组(基础饲料添加1.0%碳酸钙,0.2%醋酸铅水)、试验Ⅲ组(基础饲料添加2.0%碳酸钙,0.2%醋酸铅水)。饲养60d后,采集大鼠后肢股骨,采用荧光定量RT-PCR法测定TRPV5、TRPV6、NCX1和PMCA1b基因的mRNA表达量。结果与对照组比较,染铅组TRPV5和TRPV6 m RNΑ表达量极其显著下降(P<0.01),而NCX1和PMCA1b m RNΑ表达量极显著上升(P<0.01);与染铅组比较,试验Ⅰ组TRPV5和TRPV6 m RNΑ表达量显著上升(P<0.05),而NCX1 m RNΑ表达量显著下降(P<0.05),试验Ⅱ组TRPV5和TRPV6 m RNΑ表达量极显著上升(P<0.01),而NCX1和PMCA1b m RNΑ表达量显著下降(P<0.01或P<0.05),试验Ⅲ组TRPV6 m RNΑ表达量显著上升(P<0.05),而NCX1 m RNΑ表达量显著下降(P<0.05)。结论适量钙的补充可减轻铅暴露对骨骼TRPV通路的干扰。

Objective To investigate the effects of calcium on mRNA expression of TRPV pathway related genes in bone and explore the molecular mechanism in lead exposure rats, as well as to provide theoretical basis for calcium supplementation in minimizing lead poisoning. Methods Sixty healthy male rats were randomly divided into five groups： control group （normal diet, distilled water）, lead exposed group （normal diet, 0.2% （CH3COO）2Pb- water）, test I group （normal diet, 0.5% Ca, 0.2% （CH3COO）2Pb-water） , test II group （normal diet, 1% Ca, 0.2% （CH3COO）2Pb-water） and test III group （normal diet, 2% Ca, 0.2% （CHaCOO）2Pb-water）, respectively. After 60 days, the thigh bones of the rats were collected, and the mRNA expression levels of TRPV5, TRPV6, NCX1 and PMCAlb were quantified by real-time RT-PCR. Results Compared with control group, the mRNA expression levels of TRPV5 and TRPV6 in lead exposed group were significantly decreased （P〈0.01）, while the mRNA expression levels of NCX1 and PMCAlb in lead exposed group were significantly increased （P〈0.01）. Compared with lead exposed group, the mRNA expression levels of TRPV5 and TRPV6 in test I group were significantly increased （P〈0.05）, but the NCX1 level was significantly decreased （P〈0.05）; the mRNA expression levels of TRPV5 and TRPV6 in test II group were significantly increased （P〈0.01）, but NCX1 and PMCAlb levels were significantly decreased （P〈0.05）; the mRNA expression level of TRPV6 in test III group was significantly increased （P〈0.05）, but the NCX1 level in test III group was significantly decreased （P〈0.05）. Conclusion This findings indicate that calcium could relieve the disorders of TRPV pathway caused by lead exposure in the bone.