烫伤大鼠第三脑室伸长细胞的免疫组化研究

目的探讨伸长细胞在烫伤应激中是否参与转运促肾上腺皮质释放因子(CRF)、加压素(VP)和胆囊收缩素(CCK)等应激激素。方法在大鼠清醒状态下给予标准的25％Ⅲ°皮肤烫伤，用免疫细胞化学ABC法显示第三脑室室管膜内的伸长细胞。结果大鼠烫伤后24h大量CRF免疫反应阳性的伸长细胞出现在第三脑室底壁和外侧壁，其顶部与脑脊液接触，基部伸出一条细长的突起走向正中隆起的毛细血管附近；位于第三脑室侧壁伸长细胞的突起似与深面脑组织的毛细血管接触。未观察到含VP和CCK的伸长细胞。结论结果为伸长细胞转运CRF提供了形态学依据，提示伸长细胞可能参与应激状态下CRF超短正反馈回路的调节。

IMMUNOCYTOCHEMICAL STUDY ON TANYCYTES IN THE THIRD VENTRICLE IN SCALDING RATS

Objective To investigate whether the tanycytes transport stress hormones, such as corticotropin-releasing factor (CRF), vasopressin(VP) and cholecystokinin(CCK), etc, during scalding stress. Methods Adult male Wistar rats were given a standard scald on 25% of the body surface or only a sham. The results were studied with ABC immunocytochemical method at the light microscope level. Results There were a large number of the CRF positive tanycytes, but not VP and CCK positive ones in the third ventricle after scalding, especially in the floor and lateral wall. The top portion of tanycytes contacted with CSF and the long processes from the basal portion travelled into the underlying tissue. Some processes of tanycytes terminated in the vicinity of the capillaries in the median eminence, some of them were located in the lateral wall of the third ventricle which may contacted with the capillaries in the deeper brain tissue. Conclusion The results first provide morphological evidence that tanycytes may transport CRF selectively during scalding stress, which suggests that tanycytes of the third ventricle may be involved in regulation of CRF ultra-short positive feedback loop.