Effect of fumai yin on ultrastructure of ischemic retina in experimental rats

Chengwei GUO

ABSTRACT

BACKGROUND:

The levels of superoxide dismutase (SOD) and nitric oxide (NO) in serum reflect the efficacy of drugs on anti-ischemic damage.Fumai yin improves significantly the prognosis of visual function in ischemic hemorrhagic fundus disease.

OBJECTIVE:

To observe the effects of f umaiyin on ultrastructure of ischemic retina and serum SOD and NO activity in experimental rats.

DESIGN:

Randomized controlled observation on single sample was designed.

SETTING:

Department of Ophthalmology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine,MATERIALS The experiment was performed in Experiment Room of affiliated hospital of Shandong University of Chinese Medicine and Ultrastructure Room of Shandong University from November 2002 to July 2003.60 male Wistar rats were employed and randomized into fumaiyin group,fuming pian control group (fuming pian group) and the control group with physiological saline (PS group), 20 rats in each. Fumai yin is the concentrated decoction 2g/ml, composed of gouqizi (Fructus Lycii), huangjing (Rhizoma Polygonati), danshen (Radix Salviae Miltiorrhizae), wuweizi(Fructus Schisandrae), huangqi (Radix Astragali seu Hedysari), etc.

METHODS:

The model of retina ischemia was prepared by increasing in traocular pressure in 3 groups of rats. 0.5% pentobarbital 10 mL/kg was injected abdominally to anesthetize ocular surface. No.7 needle of tube with PS transfusion was inserted directly to bilateral anterior chambers of rats, and the infusion bottle was 145 cm above both eyes of rats, by which, 14kPa intraocular pressure was formed. It was observed that bulbar conjunctiva was pale, fundus blood flow was broken off and retina was is chemic. 1.5 hours later, the needle was withdrawn and perfusion was restored. In fumai yin group and fuming pian group, the drug was adminis trated 10 mL/kg (medicine concentration was 2 g/mL) and in PS group, PS of equal amount was applied. Gastric perfusion was done with different materials successively after modeling for 3 weeks. Colorimetry was used for assay of SOD activity and nitrate reductase method was used for assay of NO activity.MAIN OUTCOME

MEASURES:

① Comparison of serum SOD and NO activities in each group. ② Alternation of ultrastructure of ischemic retina in 3 weeks of modeling observed with transmission electron microscope (TEM) in each group.

RESULTS:

Totally 60 rats were employed in the experiment. During breeding, in PS group, 2 rats were died of gastric perfusion and1 rat was died of biting, the rest 57 rats all entered result analysis. ① Comparison of serum SOD and NO activities in each group Compared with fuming pian group, in fumai yin group, SOD activity was not changed remarkably (t=-1.165, P ＞ 0.05), but, NO activity was reduced significantly [(41.06±13.54), (27.39±7.45)μmol/L,t=3.958,P ＜ 0.01]. Compared with PS group, infumaiyin group, SOD activity was increased remarkably (t=4.628,P ＜ 0.01) and NO activity was reduced significantly (t=-3.767, P ＜ 0.01). ② Alternation of ultrastructure of ischemic retina in 3 weeks of modeling in each group In fumaiyin group, retina was distinct in layer, newlyborne membrane discs were orderly in arrangement, membrane structure was normal, the numbers of retinal ganglion cells (RGCs) and organelle structure was basically normal and there was no obvious vacuole in neu rofibrous layer. In fuming pian group, retina was distinct in layer, newly borne membrane discs were slightly disturbed in arrangement, the numbers of RGCs and each organelle structure were mostly normal and there was no obvious vacuole in neurofibrous layer. In PS group, retina was not so distinct in layers, newly-borne membrane discs were disturbed in arrangement, the structure was abnormal, the numbers of RGCs was less,organalle structure was not integrative and large vacuole presented remarkably in neurofibrous layer.

CONCLUSION:

In fumaiyin group, SOD in serum was increased significantly and NO was reduced remarkably, explaining that fumaiyin provides good protection on injury of ischemic retina, which is probably related to that fumaiyin affects SOD and NO levels in serum and alleviates the damage of retinal ultrastructure induced by ischemia.