Thymosin和LHRH在下丘脑----胸腺功能调节中的发生学研究

In the recent year studies it is shown that the hormones secreted from thymus can affect the releasing of GnRH from rat hypothalamus, consequently modulating LH secretion from hypophysis in effect on the development of sexual glands in early stage. The receptors of hypothalamus hormone GnRH also exist in the thymus, suggesting a potential relationship of interactions between thymus and hypothalamus. Accordingly, some of the scholars proposed a hypothesis of thymus-hypothalamus-hypophysis-sexual gland axis. In order to decipher the mechanism of interactions between thymus and hypothalamus, we analyzed the expression of prothymosin 1 and GnRH in the mature rats and the fetal rats that were in different stages of embryonic development, applying the techniques of immunohistochemistry, RT-PCR, in situ hybridization, and gene sequence analysis. It was found that prothymosin 1-mRNA was expressed in the preoptic area of hypothalamus of the mature rats. Furthermore, the specific bands of prothymosin 1-mRNA were successfully amplified in the preoptic area of the hypothalamus in the fetal rats that were in different stages of embryonic development. It was demonstrated with RT-PCR quantitative analysis that expression occurred at a high level in the early embryonic stage, and then trended towards a low level progressively with the maturity of the rats. The DNA sequence analysis revealed the identical nucleotide sequence of the prothymosin 1 gene derived from rat hypothalamus and thymus. Meanwhile hypothalamus hormone GnRH existed and GnRH-mRNA were expressed in the thymus of mature rats. The specific bands of GnRH-mRNA were also amplified in the thymus of fetal rats that were in different stages of embryonic development. The RT-PCR quantitative analysis indicated that expression occurred, like prothymosin 1 in hypothalamus, at a high level in the early embryonic stage, and then trended towards a low level progressively with the maturity of the rats. The DNA sequence analysis showed the identical nucleotide sequence of the hypothalamus hormone GnRH gene derived from rat thymus and hypothalamus. Our results proved on a level of molecular biology and protein that the information exchanged in a bidirectional way between the thymus and hypothalamus. This mutual exchange started in early embryonic stage, and potentially played an important role in the development t of the thymus and hypothalamus.

用RT-PCR、原位杂交、分子克隆和DNA测序方法，研究个体发生过程中胸腺素Thymosin及黄迳伤厥头偶に豅HRH在下丘脑----胸腺轴功能调节中是否有旁分泌这种产生形式，其DNA序列与原始器官分泌的是否相同。提出下丘脑----胸腺间存在有激素介导关系的新观点，从分子水平为下丘脑----胸腺之间的相互作用提供形态学和分子生物学证据。