| Interleukin-2 (IL-2) is mainly synthesized and secreted by activated T lymphocytes, and it plays an important role in the immunoloregulation of the body through stimulating the doing proliferation of the T lymphocytes by combining its specific receptors.Recently, it has been found that there is IL-2 or IL-2 like immunoreactive substance hi the central nervous system (CNS) and neuroendocrine system. For example, IL-2 like immunoreactive substance can be detected in the median eminence, arcuate nucleus, hippocampus, cerebral cortex and other parts in the brain by RIA. IL-2 receptor (IL-2R) cu P> y subunits are expressed in the CNS and neuroendocrine system, and they are distributed in different regions and with different densities in the brain., so it can be supposed that IL-2 has physiological functions hi these different regions. For instance, IL-2 has the nutrition function on the neuron and neuroglia, and affects the release of neurotransmitter.Estrogen is one of steroid hormones, which is mainly synthesized and secreted by the gonad. Estrogen, through binding specific estrogen receptor hi nucleus, functions like a nucleus transcription factor andmodulates expression of some genes. It has been found that there exist two subtypes of estrogen classical nucleus receptors; they are a and p which are different in their distribution, density and mediated action. Estrogen can cause to produce some cells rapid membrane-mediated effect, which suggests that there maybe exists a structure or a receptor which is connected with estrogen. Estrogen has an important feedback regulating function hi pituitary. It can influence not only the proliferation and hormone secretion of gonadotropic cells in pituitary, but also those of other anterior pituitary cells.It is reported that some pituitary cell lines and human pituitary tumor cells can express and secrete IL-2 and its receptors, which are mediated by some factors such as CRF and PMA. There are some evidences that there exist IL-2 and its receptors in normal anterior pituitary cells. The expression of IL-2R in different pituitary cells is not the same in the intensity of unmunostaining, PRL>ACTH>GH. It suggests that IL-2 in anterior pituitary cells can mediate proliferation of anterior pituitary cells, some anterior pituitary hormones and active substance synthesis and secretion by paracrine and autocrine.The results of our research have showed that there are IL-2 and its receptors like immunoreactive substance; their expressions have sex differences and some regularity with their sexual cycles. At the level of genes, however, it has not been reported whether there is an expression of IL-2 in the anterior pituitary of rats.Our previous research found that IL-2 immunoreactive product was colocalized with estrogen receptor (ER) hi some anterior pituitarycells of rats. IL-2 could up-regulate the gene transcription of ERa while down-regulate that of ERP in the anterior pituitary of rats. In vitro, the intensity of IL-2 immunoreactive staining and the number of IL-2 immunoreactive cells in the anterior pituitary of OVX rats supplemented with estradiol decreased more significantly than that of OVX rats. In the aspect of the function, the IL-2 influence was modulated by estrogen hi the proliferation of anterior pituitary cells of normal rats, pituitary tumor cell lines and human pituitary adenoma cells. The research showed that there existed a crosstalk between IL-2 and ER in the anterior pituitary of rats.The experiment purpose is to confirm that there is an expression of IL-2 mRNA in the anterior pituitary of normal rats, and that estrogen can influence the expression of IL-2 mRNA. It will be further testified that there is a relationship between IL-2 and ER.The following methods are adopted in our experiment:1. The anterior pituitary tissues of normal rats are isolated, and then total RNA is extracted.2. The anterior pituitary cells of normal rats are cultured for 5-7 days, then total RNA is extracted from the cultured cells.3. Th...
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