Minocycline reduces reactive hyperplasia in rat models of communicating hydrocephalus

Abstract

Objective To determine the efficacy of mlnocycline on reducing reactive hyperplasia in rat models of communicating hydrocephalus.Methods Thirty adult SD rats were randomly divided into hydrocephalic model group (n=10),minocycline-treated hydrocephalic group (n=10) and sham-operated group (n=10); rats in the first two groups were induced communicating hydrocephalus with kaolin intraventricular injections; minocycline (45 mg/kg/day) was administered to hydrocephalic rats one week after the operation; rats in the sham-operated group and hydrocephalic model group were injected with saline.The ventricular dilatation were examined by MRI and Evan' s indexes was calculated two weeks after treatment; glial fibrillary acidic protein (GFAP) and allograft inflammatory factor (AIF-1) expressions were detected by RT-PCR; GFAP and ionized calcium-binding adaptor molecule (Iba-1) were detected by immunohistochemistry and Western blotting.Results Significant difference was noted on ventricular dilatation,Evan's index,and GFAP and AIF-1 expressions among the three groups (P＜0.05); the ventricular dilatation,Evan's index,and GFAP and AIF-1 mRNA expressions increased accordingly in the sham-operated group,minocycline-treated hydrocephalic group and hydrocephalic model group (P＜0.05).Astrocytes and microglias in the sham-operated group were under dormant state; astrocytes and microglias in the model group were under hyperresponsiveness,while astrocytes and microglias in the minocycline-treated hydrocephalic group showed slight hyperplasia.The expressions of GFAP and Iba-1 in the model group were significantly higher as compared with those in the minocycline-treated hydrocephalic group (P＜0.05).Conclusion Minocycline treatment is effective in delaying the development of hydrocephalus with prospective to be the auxiliary therapeutic method of hydrocephalus. Key words: Hydrocephalus; Minocycline; Gliosis