Aim:To investigate the localization and quantity of androgen receptor(AR)in the salivary glands of rats with furtheranalysis on the effect of castration.Methods:Sixty male Wistar rats,aged 30-60 days,were randomly divided intothree groups(castrated,sham-operated and normal controls)with 20 rats in each group.The rats in the castratedgroup were castrated and the submaxillary glands were removed after 1 week.The salivary glands of the rats in thesham-operated and the normal control groups were also removed.Parts of the salivary glands were fixed for immu-nohistochemistry and in situ hybridization assays.Other parts were used for Western blot.Results:AR immunore-activity in the three groups was localized in the glandular epithelial cells of the serous acinus and the glandular duct ofthe salivary gland,mainly in the nuclei.AR mRNA hybridization signals in the salivary glands of the castrated groupwere mainly distributed in the epithelial cells of the convoluted and secretary ducts;AR mRNA in the sham-operatedand the normal control groups were found in the epithelial cells of the convoluted,the secretary and the excretoryducts.The quantity of AR in the salivary glands was decreased significantly in the castrated rats compared with thesham-operated and the normal controls.Moreover,epidermal growth factor(EGF)secreted by the salivary glandswas also decreased in the castrated rats.Conclusion:Castration appears to affect the production of AR in thesalivary gland and the distribution of the AR mRNA and could further affect the function of the salivary gland.Thechanges of AR and the distribution of AR mRNA may play an important role in the interactions between the testes andthe salivary gland. Aim: To investigate the localization and quantity of androgen receptor (AR) in the salivary glands of rats with furtheranalysis on the effect of castration. Methods: Sixty male Wistar rats, aged 30-60 days, were randomly divided intothree groups (castrated, sham -operated and normal controls) with 20 rats in each group. The rats in the castrated groups were castrated and the submaxillary glands were removed after 1 week. The salivary glands of the rats in thesham-operated and the normal control groups were also removed. Parts of the salivary glands were fixed for immu-nohistochemistry and in situ hybridization assays. Of parts were used for Western blot. Results: AR immunore-activity in the three groups was localized in the glandular epithelial cells of the serous acinus and the glandular duct ofthe salivary gland, mainly in the nuclei. AR mRNA hybridization signals in the salivary glands of the castrated group we mainly distribute in the epithelial cells of the convoluted and secretary ducts; AR mRNA in the sham-operated and the normal control groups were found in the epithelial cells of the convoluted, the secretary and the excretoryducts. the quantity of AR in the salivary glands was decreased significantly in the castrated rats compared with thesham-operated and the normal controls. Moreover, epidermal growth factor (EGF) secreted by the salivary glandswas also decreased in the castrated rats. Confluence: Castration appears to affect the production of AR in the steal gland and the distribution of the AR mRNA and could further affect the function of the salivary gland Thechanges of AR and the distribution of AR mRNA may play an important role in the interactions between the testes andthe salivary gland.