RÉSUMÉ
Objective:To study the effect of Zuoguiwan on the differentiation of CD4-CD8-T cells in thymus during the development of kidney-deficient fetal rats and the application value of kidney and essence-tonifying method, in order to explore the theoretical connotation of "kidney being the origin of congenital constitution". Method:Male and female rats were paired at a ratio of 2∶1, and three stress methods were combined to construct the kidney-deficient model. Pregnant rats were divided into control group, model group, thymosin group (0.003 g·kg-1), and low-dose Zuoguiwan group and high-dose Zuoguiwan group (2,8 g·kg-1). Normal saline was given to the control group， model group was used for modeling and given normal saline by gavage, thymosin group was given thymosin capsule solution by gavage, and low-dose Zuoguiwan group and high-dose Zuoguiwan group were given Zuoguiwan suspension by gavage. Embryos that were 16 days, 19 days and born on the first day (E16, E19, P1) were selected to calculate fetal rat thymus index. Electron microscope was used to observe thymic epithelial cell ultrastructure of fetal rats. Enzyme-linked immunosorbent assay (ELISA) method was used to detect thymus thymosinβ4 (TMSβ4) and thymosinα1 (Tα1) content, fluid cytology detection of fetal rats on the surface of CD4, CD8, CD25, CD44 expression for identifying T cell type. Result:The morphology of thymus epithelial cells in the model group was irregular, the nucleus was deformed, and the chromatin of the nucleus was significantly increased. The results of ELISA showed that the content of TMSβ4 and Tα1 in thymus increased in the model group and the low-dose and high-dose Zuoguiwan groups. Flow cytometry showed that, compared with the control group, CD4-CD8-T cells were significantly increased in the model group at E16, E19 and P1 stages (P<0.05), suggesting that T cells were blocked during the development from DN to DP. CD4-CD8-CD25-CD44-T (DN4) was significantly increased (P<0.05), suggesting that T cell development was inhibited during DN4-DP transition. Compared with the model group, CD4-CD8-T cells were significantly reduced in low and high-dose groups (P<0.05) at E16, E19 and P1 stages. At the same time, DN4 was significantly reduced (P<0.05), suggesting that Zuoguiwan could promote the development of T cells from DN4 stage to DP stage as thymosin. Conclusion:Zuoguiwan can improve the structure of thymus epithelial cells in rats with kidney deficiency, and induce the differentiation of T cells in thymus from DN4 stage to DP stage by increasing the secretion of TMSβ4 and Tα1 in thymus of embryonic rats, indicating that Zuoguiwan can promote the development and maturation of T cells and regulate the immune status of fetal rats with kidney deficiency by tonifying kidney and spermatogenesis.