Claësson M H, Tjell V
Acta Pathol Microbiol Scand C. 1976 Jun;84(3):185-95. doi: 10.1111/j.1699-0463.1976.tb00018.x.
The influence of cortisol in vivo and in vitro was studied in thymus sections, suspensions, and smears obtained from new-born, 6 days old, and 30 days old mice. Histology as well as differential counts revealed that new-born thymocytes are far more sensitive to the cytotoxic effect of cortisol than thymocytes from older animals, and thymocytes from 30 days old mice are more sensitive than cells from 6 days old animals. Thus, the number of pyknotic cells in the thymus of new-born and 30 days old mice increased up to 20 per cent 6 h after injection of cortisol compared to 10 per cent in 6 days old animals. At 24 h after injection, the per cent of pyknotic cells in the thymus of new-born mice was 50 compared with about 1 in the two older age-groups. Supravital dye exclusion showed that thymocytes in 6 days old mice are less sensitive to the cytolytic action of cortisol in vivo than thymocytes from new-born and 30 days old mice. Incorporation of 3H-TdR and 3H-UdR into thymocyte DNA and RNA, respectively, was inhibited in all groups after treatment in vivo. DNA-synthesis of thymocytes in new-born animals was inhibited in all groups after treatment in vivo. DNA-synthesis of thymocytes in new born animals was inhibited more than DNA-synthesis in thymocytes of older animals, whereas RNA-synthesis was inhibited to nearly the same extend in the three groups studied. Incubation in vitro with 10(-6)M cortisol inhibited the DNA-synthesis to the same extent in thymocytes from the three age groups studied whereas the inhibiting effect of 10(-5)M cortisol on thymocytes from 6 and 30 days old animals was more intense than that on cells in new-born mice. The RNA-synthesis of thymocytes from 6 days old mice incubated in 10(-5)M cortisol was inhibited far less than RNA-synthesis in cells from new-born and 30 days old mice. The experiments reported, showing differential effects of cortisol on thymocytes obtained from mice of different ages, may reflect different stages of thymocytes maturation during the process of ontogenesis.
研究了皮质醇在体内和体外对取自新生、6日龄和30日龄小鼠的胸腺切片、悬液及涂片的影响。组织学检查及分类计数显示，新生胸腺细胞比年长动物的胸腺细胞对皮质醇的细胞毒性作用敏感得多，30日龄小鼠的胸腺细胞比6日龄动物的细胞更敏感。因此，与6日龄动物胸腺中注射皮质醇6小时后固缩细胞数量增加10%相比，新生和30日龄小鼠胸腺中固缩细胞数量增加高达20%。注射后24小时，新生小鼠胸腺中固缩细胞的百分比为50%，而两个较年长年龄组约为1%。活体染料排斥试验表明，6日龄小鼠的胸腺细胞在体内对皮质醇的溶细胞作用不如新生和30日龄小鼠的胸腺细胞敏感。体内处理后，所有组中3H-TdR和3H-UdR分别掺入胸腺细胞DNA和RNA的过程均受到抑制。新生动物胸腺细胞的DNA合成在体内处理后所有组中均受到抑制。新生动物胸腺细胞的DNA合成比年长动物胸腺细胞的DNA合成受到的抑制更明显，而在所研究的三组中RNA合成受到的抑制程度几乎相同。体外与10(-6)M皮质醇孵育时，所研究的三个年龄组胸腺细胞的DNA合成受到同等程度的抑制，而10(-5)M皮质醇对6日龄和30日龄动物胸腺细胞的抑制作用比对新生小鼠细胞的抑制作用更强。在10(-5)M皮质醇中孵育的6日龄小鼠胸腺细胞的RNA合成受到的抑制远比新生和30日龄小鼠细胞的RNA合成受到的抑制少。所报道的实验显示皮质醇对取自不同年龄小鼠的胸腺细胞有不同作用，这可能反映了个体发育过程中胸腺细胞成熟的不同阶段。
