Effect Of Lanthanum Exposure Lactation On Oxidation Damnify Of Brain Tissue And Apoptosis Level In Nerve Cell Of Baby-rats

PrefaceRare earth elements (REEs) include lanthanum (La) in the periodic table of elements. In recent years, rare-earth techques have been applicated widely in many fields such as agriculture, farming, aquaculture, industry and medicine in China. In particular, trace fertilizer and feedstuff containing rare-earth elements (REEs) are used widespread in agriculture and farming. With widespread applications, more and more rare-earth REEs enter into the environment and accumulate in human body by food chain. Residue, accumulation of REEs in the environment and their effects on human health should not be ignored. Therefore, the effects of REEs on the environment and human health deserve further investigation.It is shown that REEs have harm effects. That means REEs have adverse effects on many tissues and organs such as brain, liver, kidney, heart of pathology change. repress immunity function, help the cell to oxidize hurt, cause chromosome mutation etc. The endanger of central nervous system system for Rare earth element is particularly worthy of value. Rare earth elements can pass a blood brain natural cover into brain organization and pass placenta natural cover from maternal get into an embryo inside body. Therefore, long-term effects of REEs on central nervous system have been paid more attention. is relation arrive excellent living excellent teach with child health.Hippocampus is the key brain region related with learning and memory. Hippocampus nerve cell of hurt for nervous system develop would creation severity influence. La is a light REE with active chemical properties, and it can react with almost all elements and components of tissues. Among REEs, La is also abundant in the environment. Furthermore, there is more accumulation of La in the brain. Therefore, La is often used as a reprensentive to probe into the neurological adverse effects of REEs. Animal model of learning and memory impairment was made in this study by subchronic administration of lanthanum chloride (LaCl₃) to rats from birth to weaning. By biochemical, immunohistochemical methods and teniques, Effect of lanthanum exposure during lactation with oxidation damnify and apoptosis of nerve cell in the brain tissue of baby-rats were investigated, study deliver of Lan process and it with the result that central nervous system system poison the mechanism of the function, Based on these data, intelligence impairment and cognition deficiency caused by La and even REEs could also be prevented effectively.Material and MethodsTwenty four Wistar rats weighing (260±10)g were obtained from the Center for Experimental Animals of China Medical University. Rats were housed at the standard laboratory condition with environmental temperature of (17～23)℃and humidity of 45～55%. The food was provided by Center for Experimental Animals of China Medical University.Animals were observed for 7 days before mating. Female rats were divided randomly into four groups: control, low-, middle- and high-dose LaCl₃ groups. Female and male rats mated (female:male= 1:1). Occurrence of copulatory plug or sperm in the vaginal discharge in the second day after mating was used to indicate successful mating and day 0 of pregnancy. During the period of lactation (3 weeks), the control lactational rats drinked distilled water, and lactational rats in low-, middle- and high-dose LaCl₃ groups were exposed to LaCl₃ (99.9%, China) in distilled drinking water under one of three doses (0.25%, 0.50%, and 1.0%; 0, 18, 36, and 72 mM respectively). The pups were firstly exposed to LaCl₃ by parental lactation for postnatal 3 weeks, respectively. After that, determine various index sign measurement.1. Each group baby-rats weight and brain organization weight, brain organization coefficient2. TBAR was used to assess the effect of Lipid peroxide Malondialdehyde in brain tissue3. DTNB was used to assess the contents of Glutathione in brain tissue4. XOD was used to assess the contents of Superoxide dismutase in brain tissue5. Improvement DTNB was used to assess the contents of Glutathione- peroxide in brain tissue6. Flow cytometry was applied to measure the effect of LaCl₃ on the apoptosis rate of. brain tissue7. The protein expression levels of bcl-2 and bax in the hippocampus of pups were measured by immunohistochemistry.Results1,Each group baby-rats weight and brain organization weight, brain organization coefficientBaby-rats weight of high -dose LaCl₃ groups were significantly lower than that of control group, brain organization coefficient of other LaCl₃ groups were significantly lower than that of control group2,Results of Lipid peroxide of brain tissueThe contents of MDA in the brain tissue of LaCl₃-administrated pups were significantly higher than those of control group. With LaCl₃-administrated dose increasing, The contents of MDA in the brain tissue of pups increased.The contents of SOD in the brain tissue of LaCl₃-administrated pups were significantly lower than those of control group. With LaCl₃-administrated dose increasing, The contents of SOD in the brain tissue of pups decreased .The contents of GSH in the brain tissue of LaCl₃-administrated pups were significantly lower than those of control group. With LaCl₃-administrated dose increasing, The contents of GSH in the brain tissue of pups decreased .The contents of GSH-Px in the brain tissue of low-dose LaCl₃ group and control group were significantly lower than those of middle-dose LaCl₃ group and high-dose LaCl₃ group, high-dose LaCl₃ group were significantly lower than middle-dose LaCl₃ group. 3,Changes in apoptosis rateLanthanum exposed to high-dose group and high-dose LaCl₃ group the rate of apoptosis compared with the control group significantly increased, and low-dose LaCl₃ group compared with the control group not significantly(P >0.05), but has trend to increased, Increase Lanthanum exposed can increased the rate of apoptosis.4. Effects of LaCl₃ on bcl-2 and bax in the hippocampus of ratsThe expression levels of bcl-2 in the hippocampus of high-dose and middle-dose LaCl₃ group were significantly lower than those of control group and low-dose group. The expression levels of bax in the hippocampus of high-dose LaCl₃ group were significantly increaser than those of control, low- dose LaCl₃ groups.Conclusion1. lanthanum exposure during lactation can decreased GSH,SOD,GSH-Px in the brain tissue on baby rats and cause Lipid peroxide.2. lanthanum exposure during lactation advance apoptosis of nerve cell in the brain tissue of baby-rats, decrease the activities of bcl-2 protein and increase the activities of bax protein in the hippocampus.