RESUMO
OBJECTIVE: To observe the effects of chronic lead exposure on mRNA and protein expression of ASIC1a, ASIC2a, ASIC2b in hippocampus of baby-rats. METHODS: The Wistar pregnant rats were randomly divided into 3 groups fed with distilled water or lead contained water (0.2% and 1.0% lead acetate) respectively, 5 rats in each group. The lead-exposure ranged from the 0 day of pregnancy to the offspring weaned. Then the baby-rats were fed with lead water like their mothers and killed at postnatal day 8 or 50. Atomic absorption spectrometry was used to determine lead content in the brain. RT-PCR and Western blotting were used to observe mRNA and protein expression of ASIC1a, ASIC2a and ASIC2b in their hippocampus respectively. RESULTS: The brain lead content of test groups was higher than that of the control group (P < 0.01), and the lead content of the postnatal day 50 was higher than that in postnatal day 8 (P < 0.01). Compared with the control group, ASIC1a mRNA expression of 1.0% lead exposure in the hippocampus was uptrend (P < 0.01), ASIC1a protein expression of each test group was downtrend (P < 0.05), while for ASIC2a and ASIC2b mRNA and protein, there was no significant differences observed (P > 0.05). CONCLUSION: ASIC1a expression in hippocampus can be changed by chronic lead exposure.
Assuntos
Hipocampo/metabolismo , Chumbo/toxicidade , Proteínas do Tecido Nervoso/metabolismo , Efeitos Tardios da Exposição Pré-Natal/genética , Canais de Sódio/metabolismo , Canais Iônicos Sensíveis a Ácido , Animais , Feminino , Hipocampo/efeitos dos fármacos , Proteínas do Tecido Nervoso/genética , Gravidez , RNA Mensageiro/genética , Ratos , Ratos Wistar , Canais de Sódio/genéticaRESUMO
OBJECTIVE: To observe the effect of chronic lead contaminant on protein expression of protein kinase (PKC) and calmodulin (CaM) in hippocampus of baby-rats. METHODS: The Wistar pregnant rats were randomly divided into 3 groups fed with distilled water and lead-contained water (0.2% and 1.0% lead acetate) respectively. The lead exposure period ranged from the 0 day of pregnancy to the offspring weaned. Then the baby-rats were fed with lead water the same as their mothers. Pups were killed at postnatal day 8 and 50 respectively. Atomic absorption spectrometry was used to determine lead content of rats' brain. Western-blotting was used to observe protein expression of PKC and CaM in hippocampus of baby-rats. RESULTS: The brain lead content of test groups was much higher than that of the control group in the same growth period (P < 0.01). The content of brain lead in rats of postnatal day 50 was significantly higher than that of rats of postnatal day 8 (P < 0.01). Compared with control group, PKC and CaM protein expressions of chronic lead exposure baby-rats in the hippocampus were down trend (P < 0.05). CONCLUSION: The decrease of PKC and CaM protein expression level in hippocampus might be one of the molecular mechanisms of lead induced impairment of learning and memory.