Effects of Jiannaoan on glucocorticoid receptor in hippocampus neurons of rats

Cuibai WEI; Jinzhou TIAN; Jianping JIA; Yipeng TANG; Lin PAN

ABSTRACT

BACKGROUND:

The previous experiments have conformed the traditional Chinese medicine (TCM) Jiannaaan, with the effects of tonifying kidney, promoting blood circulation and resolving phlegm, can inhibit the increased content of glucocorticoid (GC) in 2-24 hours after cerebral ischemic reperfusion (CIR), and reduce toxic effects of promoting nervous cell apoptosis induced by high GC. However, it is unclear whether this effect exists in GC receptor (GR).

OBJECTIVE:

To observe the intervention of TCM Jiannaoan on GR,further study protective mechanism of Jiannaoan power to hippocampal neurons after CIR, and perform positive control with compound almitrine.

DESIGN:

A randomized and controlled trial taken animals as subjects.

SETTING:

Center Laboratory of Beijing University of Chinese Medicine.MATERIALS The experiment was conducted at the Center Laboratory of Beijing University of Traditional Chinese Medicine between July 2002 and March 2003. Eighty male SD rats were randomized into 5 groups with 16 in each Sham group, model group, treatment group, positive control group and antagonist group. And each group was divided into 4 subgroups 2, 6,12 and 24 hours after CIR, with 4 rats at every time point.

METHODS:

①Administration Except model group, rats in other 4 groups were administrated by intragastric infusion since 7 days before model establishment, once per day, with dose of 7 μL/g per day distilled water in sham group, 7.39 mg/kg per day compound almitrine in positive control group, 6.7 g/kg per day Jiannaoan crude drug (consisted of desertliving cistanche herb, tatarinowii sweetflag rhizome and rhubarb, etc) in treatment group and 10 g/kg per day GR antagonist mifepristone in antagonist group.② After 7-day administration, the CIR models were prepared on the experimental rats with middle cerebral artery occlusion (MCAO) filament method, while the rats in sham group were sutured after common carotid artery detachment at anesthesia, without filament.MAIN OUTCOME

MEASURES:

All the rats were executed to take out brains at different time points of reperfusion, and the change of GR protein expression was observed with immunohistochemical method then the amount of positive cells were calculated in 3×200 sight of CA2 region.

RESULTS:

Totally 80 rats were entered into the result analysis. Compared with uninjured side, the protein expression of GR in model group,treatment group, positive control group and antagonist group were significantly lower than that of sham group (P ＜ 0.05), in which GR expression of injured side was equal to that of uninjured side without significant difference. No obvious change was found in the protein expression of GR among treatment group, positive group and antagonist group at different time points of reperfusion, and no significant difference was found between above groups and model group (P ＞ 0.05).

CONCLUSION:

Jiannaoan power is selective for adjusting GR and content of GC Jiannaoan can not adjust expression of GR, identical as compound almitrine; But Jiannaoan can protect the neurons through decreasing the content of GC in plasm and brain tissues after CIR.