Effect of subchronic lanthanum exposure on amino acid neurotransmitters in hippocampi of offspring rats

ObjectiveTo investigate the effect of lanthanum on neurobehavioral ability and amino acid neurotransmitter contents in hippocampal tissues of offspring rats.MethodsHealthy female adult Wistar rats were randomly divided into control,low,moderate,and high dose groups (6 rats in each group) and exposed to 0,0.25%,0.50%,and 1.00% lanthanum chloride (LaCl₃) in drinking water from pregnancy to one month after weaning.The offspring rats of the experimental Wistar rats were also treated with various dosages of LaCl₃ in drinking water till one month after weaning.Shuttling boxes assay was used to assess neurobehavioral changes in offspring rats of the experimental rats;high performance liquid chromatography was used to detect the levels of excitatory and inhibitory amino acid neurotransmitters in hippocapi of the offspring rats.ResultsThe shock time and active escape latencies were 26.00±8.11s and 6.50±2.45 s for the offspring rats of moderate dose group,and 36.38±5.88 s and 9.38±3.50 s for those of high dose group,respectively,which were significantly prolonged when compared with those of the offspring rats of control group (all P<0.05),suggesting learning and memory damage of the offspring rats of exposure groups.The levels of glutamate (Glu) and aspartate (Asp),both being excitatory amino acid neurotransmitters,were 8.16±2.16 μmol/gpro and 12.05±4.86 μmol/gpro in the hippocapi of offspring rats of moderate exposure group and 8.91±3.48μmol/gpro and 12.33±4.57 μmol/gpro in those of high exposure group,respectively,which were significantly increased compared with those of the offspring rats of the control group (all P<0.05).The levels of glycine (Gly),γ-aminobutyric acid (GABA),and taurine (Tau),all being inhibitory amino acid neurotransmitter,were 9.95±3.41μmol/gpro,13.25±5.03 μmol/gpro,and 10.93±3.53 μmol/gpro and 14.50±4.90 μmol/gpro,10.10±3.18 μmol/gpro,and 13.78±5.28 μmol/gpro for the offspring rats of moderate and high dose exposure groups,respectively,which were significantly increased in dose-effect manner compared to those of the offspring rats of the control group (all P<0.05).ConclusionMaternal subchronic lanthanum exposure could lead to learning and memory damage in offspring rats,which may be related to the elevation of excitatory and inhibitory amino acid neurotransmitters in hippocampal tissues.