[Hydrogen rich water attenuates pregnancy gingivitis induced by ligation in SD rats].

PURPOSE: To investigate the effect of hydrogen rich water on experimental gingivitis in SD rats during pregnancy. METHODS: Female SD rats mated with male ones were chosen to induce experimental gingivitis after ligation for 2 weeks. The pregnant rats were randomly divided into control group, model group and HW group. In the control and model group, rats were given pure water, while animals in the HW group were given hydrogen-rich water twice a day. All pregnant animals were sacrificed on day 16 of pregnancy. The level of Prog, SOD and TNF-α in the gingiva of different groups were measured by ELISA, the expression of PR, NFκB and TNF-α were determined by immunohistochemistry and Western blot. SPSS 13.0 software package was used for data analysis. RESULTS: Pregnancy gingivitis of SD rats could be induced by thread ligation. PR was mainly distributed in the gingival epithelium, while there was no significant difference of Prog and PR in the gingiva among different groups(P>0.05). Furthermore, in the model group, lower SOD level as well as higher NFκB and TNF-α level were found in the gingiva. Compared with the model group, the inflammatory response of pregnancy gingivitis in HW group was significantly suppressed along with decreased NFκB and TNF-α. CONCLUSIONS: Progesterone and its receptor may play an indirect role in the process of pregnancy gingivitis of rats. Hydrogen rich water may be beneficial in suppressing pregnancy gingivitis progress by decreasing inflammatory response related to gingival oxidative stress.

Correlation of Alzheimer-like tau hyperphosphorylation and fMRI bold intensity.

To explore the correlation between cerebral functional alterations revealed by functional magnetic resonance imaging (fMRI) and Alzheimer disease- (AD)-like tau hyperphosphorylation, we injected bilaterally 2 microl each of 20 mM isoproterenol (IP), a PKA activator, or of saline as a vehicle control into the hippocampus of rats. FMRI was employed to measure the intensity of BOLD signal, one of the cerebral functional markers reflecting the changes of cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow (CBF), in hippocampus and cortex 24 h after the operation. Immunohistochemical staining of hippocampus and cortex was carried out using phosphorylation-dependent tau antibodies. The results showed (1) that BOLD intensity in hippocampus and cortex of IP-injected rats was obviously lower than that of sham-operated group, indicating a decrease in CMRO2 and CBF of the particular brain regions in IP-treated rats; (2) that tau was hyperphosphorylated at Ser-262/Ser-356 (12e8), Ser-396/Ser-404 (PHF-1) sites in CA1 CA2 CA3 CA4 and dentate gyrus regions of hippocampal formation and cortex area in IP group, but not in sham rats; (3) that a negative correlation between tau hyperphosphorylation and BOLD intensity in hippocampus and cortex area of IP rats was observed. The data suggested that hippocampal and cortical tau hyperphosphorylation was intimately related to BOLD intensity of the same areas. To our knowledge, this is the first report exploring the relationship between fMRI BOLD signal and AD-like tau hyperphosphorylation.