[Effects of NaHS on MBP and learning and memory in hippocampus of mice with spinocerebellar ataxia].

Objective: To investigate the effects of exogenous NaHS on myelin basic protein (MBP) and learning and memory of hippocampal neurons in mice with spinocerebellar ataxia type 3 (SCA3) and its therapeutic significance.Methods: Twelve male normal mice were randomly selected as normal control group (NC Group), and 48 SCA3 mice were randomly selected as SCA3 model group (M Group), low dose group (NL Group, 10 µmol/kg), medium dose group (NM Group, 50µmol/kg) and high dose group (NH Group, 100 µmol/kg), 12 rats in each group. The drug treated groups were injected with NaHS intraperitoneally once a day for 4 weeks. The changes of learning and memory ability of SCA3 mice before and after the intervention of different doses of NaHS were determined by Morris water maze, the content of hydrogen sulfide (H2S) in hippocampus was measured by spectrophotometry, the expression of MBP was detected by immunohistochemistry, and the morphological changes of neuron myelin sheath were observed by electron microscope. Results: Compared with the control group, the learning and memory ability of SCA3 mice was decreased significantly (P＜0.05), and the content of H2S in hippocampus was decreased (P＜0.05). After different doses of exogenous NaHS treatment, the learning and memory ability was improved in different degrees (P＜0.05), and the contents of H2S and MBP in hippocampus of SCA3 mice were also improved in different degrees (P＜0.05). Conclusion: Exogenous NaHS may increase the contents of H2S and MBP in the hippocampus of SCA3 mice, which may have a protective effect on the neurons, and then improve the learning and memory ability of SCA3 mice, and provide a new idea for the treatment of SCA3.

[Influence of different duration of waterlogging on the growth and C and N metabolism of soybean at seedling and flowering stages].

A pot experiment with soybean cultivar Nannong 99-6 was conducted to study its growth and C and N metabolism at seedling and flowering stages under the stress of different duration of waterlogging. Waterlogging inhibited the soybean growth. The plant biomass, leaf area, leaf pigment content, and photosynthesis rate all decreased significantly, and the leaf malonyldialdehyde (MDA) content had a significant increase. The change ranges of the physiological indices increased with increasing waterlogging duration. After the release of the stress, the plants had some recovery. The recovery capability in treatment waterlogging for 10 d was stronger than that in the treatment waterlogging for 20 d. The leaf soluble C and N and key enzymes had different responses to waterlogging. Soluble sugar content and glutamine synthease and sucrose synthease activities all increased, but soluble protein content decreased. The influence of waterlogging on the plant biomass, leaf area, and MDA content was smaller at seedling stage than at flowering stage. It was suggested that the shorter the waterlogging duration was, the lesser damage the soybean plant suffered, and the stronger the recovery capability was. Soybean plant could recover itself after waterlogging for 10 d.