不同剂量藏红花提取液对大鼠慢性高眼压模型视神经及轴浆流的影响

Effects of different doses of Stigma Croci extract on optic nerve and axoplasma flow in rats with chronic ocular hypertension

目的探讨藏红花提取液不同剂量对大鼠慢性高眼压视神经损伤及轴浆流的影响。方法32只SD大鼠,以随机数字表法分为对照组、高眼压组、低剂量组和高剂量组,每组8只大鼠,16只眼。高眼压组和低剂量组、高剂量组的大鼠剪开球结膜,烧灼涡静脉制作慢性高眼压模型,对照组仅剪开结膜。低剂量组、高剂量组动物腹腔分别注射藏红花提取液20 mg/kg和80 mg/kg;高眼压组和对照组各注射0.5 mL生理盐水,连续28 d。动物麻醉致死,取球后视神经和视网膜,视神经作超薄切片,电镜下观察;逆行荧光金观察轴浆流及节细胞情况。结果对照组视神经超微结构清晰,高眼压组视神经超微结构破坏严重,低剂量组的视神经超微结构改善,高剂量组视神经超微结构明显改善且接近于对照组。与对照组比较,高眼压组轴突数量减小,差异有高度统计学意义(P<0.01),与高眼压组比较,低剂量组和高剂量组轴突数量增多,差异均有高度统计学意义(均P<0.01),与低剂量组比较,高剂量组轴突数量增多,差异有高度统计学意义(P<0.01)。对照组标记视网膜神经节细胞各象限分布均匀,细胞外未见荧光金渗漏。高眼压组视网膜神经节细胞各区域密度低,分布不规律,部分荧光金渗漏。低剂量组视网膜神经节细胞数目增多,个别细胞可见突起。高剂量组视网膜神经节细胞数目丰富,无渗漏,部分突起清晰可见。与对照组比较,高眼压组逆行荧光金标记节细胞数量减小,差异有高度统计学意义(P<0.01),与高眼压组比较,低剂量组和高剂量组逆行荧光金标记节细胞数量增多,差异均有高度统计学意义(均P<0.01),与低剂量组比较,高剂量组逆行荧光金标记节细胞数量增多,差异有高度统计学意义(P<0.01)。结论慢性高眼压可致大鼠视神经超微结构损伤及轴浆流阻断;藏红花高剂量组对慢性高眼压视神经损伤和轴浆流有显著的保护作用。

Objective To investigate the effects of different doses of Stigma Croci extract on optic nerve injury and axoplasma flow in rats with chronic ocular hypertension.Methods A total of 32 SD rats were divided into control group,high ocular hypertension group,low dose group and high dose group by random number table method,with 8 rats and 16 eyes in each group.The bulbar conjunction of rats in the high ocular hypertension group,low dose group and high dose group were cut open,and the cauterized vortex veins were used to make the model of high chronic ocular hypertension,while the bulbar conjunction was only cut open in the control group.The low dose and high dose groups were intraperitoneally injected with 20 mg/kg and 80 mg/kg of Stigma Croci extract respectively and the high ocular hypertension group and the control group were injected with 0.5 mL normal saline for 28 consecutive days.All rats were sacrificed by anesthesia and optic nerves behind the eyeball and retina slices were collected.Ultrathin sections of optic nerve were made and observed under electron microscope.The axoplasma flow and the retinal ganglion cells were observed with countercurrent fluoro-gold.Results The ultrastructure of the optic nerve in the control group was clear,the ultrastructure of the optic nerve in the high ocular hypertension group was seriously damaged,and the ultrastructure of the optic nerve in the low dose group was improved,while the ultrastructure of the optic nerve in the high dose group was significantly improved and close to the control group.Compared with the control group,the number of axons in the high ocular hypertension group decreased,and the difference was highly statistically significant(P<0.01).Compared with the high ocular hypertension group,the number of axons increased in the low dose group and the high dose group,and the differences were highly statistically significant(all P<0.01).Compared with the low dose group,the number of axons increased in the high dose group,and the difference was highly statistically significant(P<0.01).In the control group,the labeled retinal ganglion cells were evenly distributed in all quadrants,and no fluoro-gold leakage was observed outside the cells.Retinal ganglion cells in the high ocular hypertension group had low density in each area and irregular distribution,and some fluoro-gold leakage.The number of retinal ganglion cells increased and individual cells had prominences in the low dose group.In the high dose group,the number of retinal ganglion cells was abundant and there was no leakage and some of the prominences were clearly visible.Compared with the control group,the number of countercurrent fluoro-gold labeled ganglion cells in the high ocular hypertension group decreased,with a highly statistically significant difference(P<0.01).Compared with the high ocular hypertension group,the number of countercurrent fluoro-gold labeled ganglion cells increased in the low dose group and the high dose group,and the differences were highly statistically significant(all P<0.01).Compared with the low dose group,the number of countercurrent fluoro-gold labeled ganglion cells increased in the high dose group,and the difference was highly statistically significant(P<0.01).Conclusion Chronic ocular hypertension can destroy the ultrastructural appearance of rat retrobulbar optic nerve and cut down axoplasm flow;the high dose Stigma Croci extract has a protective effect on the optic nerve and axoplasm flow injured by chronic ocular hypertension.