The Effect Of Huoxuehuayu Decoction On Endoplasmic Reticulum Stress Of Retina In Acute Ocular Hypertension Of Rats

Objective To investigate the effects of Huoxuehuayu decoction on endoplasmic reticulum stress (ERS) of retina in acute ocular hypertension of rats.Methods Eighty-eight adult healthy Wistar rats were randomly divided into control group (8 rats), intraocular hypertension group (40 rats), and treatment group (40 rats). One eye of each rats were modeled by increasing intraocular hypertension (IOP) except the control group. The rats of the treatment group were given Huoxuehuayu decoction 4ml/d by oral after increasing IOP. The rats of both intraocular hypertension group and treatment group were randomly put to death after 12h,1d,3d,7d and 14d by equal. Hematoxylin and eosin stain (HE) method was used for observing the morphologic changes of retina. The expression of GRP78—one of the ERS markers was detected by immunohistochemistry. GRP78mRNA level was detected by real time fluorescence quantitative RT-PCR.Results 1. Light microscope:After 12h of increasing IOP for intraocular hypertension group, the retina was dropsical and became thick, the nuclear swelled. 1d after increasing IOP, the edema of retina became serious.3d after increasing IOP, the edema was alleviative, the numbers of retinal ganglial cells (RGCs) decreased. The retina became thin.7d after increasing IOP, RGCs loosely arranged.14d after increasing IOP, only few RGCs can be seen, the retina became atrophic. The retina of treatment group had the same change at the same time stage, but slighter than intraocular hypertension group.2. Immunohistochemistry:For the intraocular hypertension group,12h after increasing IOP, the expression of GRP78 increased rapidly compared with control group(P<0.05). 1d after increasing IOP, GRP78 got to the peak(P<0.05).3d after increasing IOP, GRP78 decreased rapidly, but still higher than control group(P<0.05). For treatment group,12h after increasing IOP, GRP78 increased rapidly compared with control group (P<0.05). 1d after increasing IOP, GRP78 got to the peak, but lower than intraocular hypertension group (P<0.05).3d after increasing IOP, GRP78 decreased and lower than intraocular hypertension group (P<0.05).7d and 14d after increasing IOP, there were no statistic significance among intraocular hypertension group,treatment group and control group (P>0.05).14d after increasing IOP, the expression of Thy-1 of both intraocular hypertension group and treatment group were lower than control group, but the expression of Thy-1 of treatment group was higher than that of intraocular hypertension group.3. real time fluorescence quantitative RT-PCR:For the intraocular hypertension group,12h after increasing IOP, the expression of GRP78mRNA increased rapidly compared with control group(P<0.05). 1d after increasing IOP, GRP78mRNA got to the peak (P<0.05).3d after increasing IOP, GRP78mRNA decreased rapidly, but still higher than control group(P<0.05). For treatment group,12h after increasing IOP, GRP78mRNA increased rapidly compared with control group (P<0.05). 1d after increasing IOP, GRP78mRNA got to the peak, but lower than intraocular hypertension group (P<0.05).3d after increasing IOP, GRP78mRNA decreased and lower than intraocular hypertension group (P<0.05).7d and 14d after increasing IOP, there were no statistic significance among intraocular hypertension group,treatment group and control group (P>0.05).14d after increasing IOP, Thy-1mRNA of both intraocular hypertension group and treatment group were lower than control group, but Thy-1mRNA of treatment group was higherthan that of intraocular hypertension group. Conclusion ERS participates in the process of retinal damage caused by acute intraocular hypertension. Huoxuehuayu decoction has protective effect on retinal injury which induced by acute intraocular hypertension. This protective effect may have relations with that Huoxuehuayu decoction can suppress ERS.