Gene Expression Of Mg²⁺ Transporters In Eye Tissue In 6-OHDA Induced Parkinson Rats

Objective1. To study the influence of MgSO₄ on the behavior of the 6-OHDA induced hemiparkinsonium rats.2. The change of gene expression of Mg²⁺ transporters in eye tissue in 6-OHDA induced hemiparkinsonium rats after MgSO₄ supplemention.3. The changes of dopaminergic neurons in retina of 6-OHDA induced hemiparkinsonium rats after MgSO₄ supplemention. Methods1. A hemiparkinsonium rat PD model was established by a unilateral injection of 6-hydroxydopamine?6-OHDA? into the right medial forebrain bundle?MFB?.2. Animals were randomly divided into 4 groups: control, control+MgSO₄, PD, and PD+MgSO₄ groups. Magnesium sulfate administration on a daily basis?MgSO₄?7H₂O, 90mg/kg, i.p.? started 30 min following 6-OHDA injection, and maintained for 1 and 2 weeks respectively. The behavior was evaluated by intraperitoneal injection APO and curling Test. The changes of retinal dopaminergic neurons were evaluated by the TH immunohistochemistry.3. The m RNA expressions of SLC41A1?Mag T1?CNNM2 in eye tissue were detected by Q-PCR. Results1. APO-induced rotational behavior there was no significant difference between the PD+MgSO₄?261±85?r/30 min and PD?309 ± 109? r/30 min groups after 1 week MgSO₄ supplemention. The contralateral rotational behavior in the PD+MgSO₄ group?182 ± 49? r/30 min was significantly lower than those in the PD group?248 ± 60? r/30min?P <0.01? after 2 weeks MgSO₄ supplemention.2. Curling Test after 1 week MgSO₄ supplemention, the score in PD group?16 ± 2.6? was significant higher than that in control?7.3 ± 2.9??p<0.05?; the score in PD+MgSO₄ group?12.6 ± 1.5? was significant lower than that in PD group?p<0.05?. Similarly, after 2 weeks MgSO₄ supplemention, the score in PD group?16 ± 3.3? was significantly higher than that in control?4.3±1.5??p<0.01?; the score in PD+MgSO₄ group?11 ± 3.8? was significantly lower than that in PD group?p<0.05?.3. Mg2+ concentration in whole blood after 1 and 2 weeks MgSO₄ supplemention, the Mg2+ concentrations in control+MgSO₄, PD+MgSO₄ and PD groups were significant less than that in control group?p<0.05?.4. Q-PCR results after 1 week MgSO₄ supplemention, comparing PD group with control group, the m RNA expression of CNNM2, SLC41A1, Mag T1 in the ipsilateral eye to the lesion in the PD rats reduced markedly?p<0.01?, and both the m RNA expression of CNNM2 and Mag T1 in the contralateral eyes declined as well?p<0.01?, but there were no significant difference in the contralateral side of SLC41A1. Comparing PD+MgSO₄ with PD group, the m RNA expression of CNNM2, SLC41A1, Mag T1 in the ipsilateral side increased markedly?p<0.01?, the expression of CNNM2 and Mag T1 in the contralateral side increased?p<0.01?, but there were no significant differences in SLC41A1. Comparing control+MgSO₄ with control group, the m RNA expression of CNNM2 in the ipsilateral side declined?p<0.05?, but the contralateral side was increased?p<0.05?. There was no significant differences in the m RNA expression of SLC41A1 in the ipsilateral side, but there was significantly reduced in the contralateral side?p<0.05?; the m RNA expression of Mag T1 was significant decreased in both eyes?p<0.05?.After 2 weeks MgSO₄ supplemention, the m RNA expression of CNNM2, SLC41A1, Mag T1 in the PD group in both eyes were reduced markedly when compared with the control group?p<0.01?. Comparing PD+MgSO₄ with PD group, the m RNA expression of CNNM2, SLC41A1, Mag T1 in the both eyes were significantly increased?p<0.05?. Comparing control+MgSO₄ with control group, the m RNA expression of CNNM2 in the ipsilateral side were decreased?p<0.05?, but there were no significant differencs in the contralateral side. There were no significant differences in the m RNA expression of SLC41A1 in both eyes, and there were no significant differences in Mag T1 in the ipsilateral side, but there was markely reduced in the contralateral side?p<0.05?.5. Immunohistochemical staining the intensity of TH positive cells in theretinal inner nuclear and the inner plexiform layer in PD group was significantlydecreased when compared with control?p<0.05?. After 1 and 2 weeks MgSO₄supplemention, comparing PD+MgSO₄ with PD group, the intensity of TH positivecells in the inner nuclear and the inner plexiform layer was increased significantly?p<0.01?. Conclusion1. MgSO₄ could improve the movement beheavior in 6-OHDA induced PD rats.2. The m RNA expression of CNNM2, SLC41A1, Mag T1 in eye in PD rats were downregulation, but this phenomenon will be reversed after MgSO₄ supplemention.3. MgSO₄ could improve TH cells in the retinal inner nuclear and the inner plexiform layer in 6-OHDA induced PD rats.4. The blood Mg²⁺ in PD rats was decreased.