大鼠颌下腺及其离体培养细胞脱氢表雄酮（DHEA）的免疫组织化学定位

用免疫组织化学ABC法，研究了颌下腺及无血清培养的颌下腺上皮细胞DHEA的定位，结果显示，大鼠颌下腺的浆液性腺泡的上皮细胞及各级导管上皮细胞均呈DHEA免疫反应阳性，无血清培养腺上皮细胞也呈DHEA免疫反应阳性，阳性物质分布于胞质，胞核呈阴性反应，此结果提示：大鼠颌下腺能自身合成DHEA，DHEA对消化功能可能具有重要的调节作用。

IN VIVO AND IN VITRO THE IMMUNOLOGICAL LOCALIZATION OF DHEA IN RAT SUBMAXILLARY GLAND

The submaxillary is situated below the floor of the mouth just beneath the body of the mandible. The secretory portion of the gland is composed of tubulo-alveolar acini of the mucous and serous types, their secretion contains many enzyme which hydrolyzes the polysaccharide starch into the disaccharides maltose and isomaltose. Previous studies have described that rat submaxillary could not only secret digestive fluid but also synthesize many biological activated substance, such as nerve growth factor(NGF), epithelial growth factor(EGF), retina nodal cell nerve induced factor, 5-HT and GnRH etc. DHEA is the precursor of sexual hormone, this substance and its combination can be situated in the rat brain whose suprarenal or testis is ablated. Recent studies have found that DHEA could also exist in adrenal gland, uterus and testis. However, whether DHEA could exist in submaxillary remains unknown. This study was undertaken to demonstrate the localization of DHEA in submaxillary gland and the epithelial cells from submaxillary gland cultured in serum free medium. The paraffin and culture sections were washed by PBS (pH 7.1, 0.01 mol/L)for five minutes three times, and incubated in methanol-H2O2 for 20 min to remove endogenous peroxidase and then washed by PBS(pH7.1, 0.01 mol/L) 5 minutes three times. They were then stained according to the immunohistochemical ABC method. Tissue sections were incubated at 4℃ for 24 hr in the primary antibodies of rabbit anti-DHEA antibody and rabbit anti-keratin antibody(1∶100 dilution), respectively. The secondary antibody, biotin-labeled horse anti-rabbit IgG(1∶200 dilution) was incubated at room temperature for one hour and ABC complex(1∶100 dilution) incubated at room temperature for 30 min. The negative control tissue sections were incubated with normal rabbit serum and phosphate buffer salt as primary antibodies. The results showed that the epithelial cells cultured in serum free medium exhibited keratin positive reaction, the positive substance was distributed in cytoplasm and the nuclei was negative. The glandular epithelial cells of serous acinus and all gland ducts produced DHEA positive immunoreaction. Similarly, the epithelial cells of submaxillary gland cultured in serum free medium showed DHEA immunoreactivity. The positive immunoreactive substance was distributed in the cytoplasm with negative nuclei. In control test, the epithelial cells of serous acinus and of excretory duct in rat submaxillary gland was showed negative immunoreaction. The results indicated that the cells cultured in serum free medium were submaxillary gland epithelial cells, and these cells also showed DHEA positive reaction, which suggeste that the DHEA may be synthesized in the serous acinus of submaxillary gland of rat and it may play an important role in the regulation of digestive function.