养阴清热中药拮抗地塞米松诱导兔生长延滞的作用机理研究

The Mechanisms of Yangyin Qingre Chinese Medicine in Inhibiting Growth Retardation induced by Dexamethasone

目的:观察养阴清热中药对地塞米松诱导免生长延滞的作用及其可能的机制。方法:1个月龄新西兰免30只,随机分为3组:正常对照组、地塞米松组和中药治疗组,每组动物为10只。地塞米松组和中药治疗组按地塞米松5mg/kg体重,每天肌肉注射给药。中药治疗组给予混有养阴清热中药的颗粒饲料,正常对照组及地塞米松组均给予普通饲料,分别在给药后第6、12周时处死。测量胫骨长度并取生长板标本。免疫组织化学染色测定关节软骨中IGF-I表达的阳性指数,实时荧光定量PCR检测IGF-I mRNA在各组的表达。结果:6周地塞米松组的胫骨长度及体重小于正常对照组,其差异有统计学意义(P<0.05)。12周中药治疗组与地塞米松组的胫骨长度及体重差异有统计学意义(P<0.05)。6、12周地塞米松组IGF-I的阳性指数、IGF-I mRNA表达水平明显低于正常组,差异有统计学意义(P<0.01),中药治疗组IGF-I阳性指数、IGF-I mRNA表达水平明显高于地塞米松组,差异有统计学意义(P<0.01)。结论:养阴清热中药可以拮抗地塞米松诱导免的生长延滞作用;养阴清热中药可能是通过调控生长板中IGF-I而减轻地塞米松对生长板的抑制作用。

Objective：To observe the effects and potential mechanisim of Yangyin Qingre Chinese herbal medicine in inhibiting growth reatardation induced by dexamethasone in rabbits. Methods： Thirty one month-old New Zealand rabbits were randomly divided into normal group, dexamethasone group and Chinese herbal group, 10 rabbits in each group. The rabbits in dexamethasone group and Chinese herbal group were treated with intramuscular injection of dexamethasone （5mg/kg）. The rabbits in Chinese herb were fed by pellet containing Chinese herb. And the rabbits were sacrificed at the 6th and 12th week after administration, and then rabbit tibia articular was collected. Body weight and tibia easure length were detected. Immunohistochemical staining was performed to investigate the expression of insulin like growth factor I. Fluorescent quantitative PCR was used to detect the expression of IGF I mRNA in each group. Results： At the 6th week after adminis tration, the tibia length and body weight in dexamethasone group were lower than those in normal group （P〈0. 05）. At the 12th week, there was significant difference between Chinese herbal group and dexamethasone group both in length and weight （P〈0. 05）. Immunohistochemical staining and fluorescent quantitative PCR indicated that the expression of IGF-I and IGF-I mRNA in dexamethasone group was significantly decreased compared with those in normal group （P〈0. 01）, and also obviously lower than Chinese herbal medicine-treated group group （P〈.O. 01） at the 6th and 12th week. Conclusion： Yangyin Qingre Chinese herbal can reduce the growth retardation induced by Dexamethasone through increasing the IGF I expression in growth plate chondrocytes.