The Different Expression Of Melatonin And Melatonin Receptor In Human Thyroid Neoplasm

As one of the important neuro-endocrinology hormone, melatonin was usually taken as a hormone which mainly regulate the physiology rhythm in living body. With the proceeding of melatonin research these years, it has been found gradually that melatonin can regulate the function of reproductive system and immune system; modulate sleep and mood; affect the function of cardiovascular system and endothelium and have the function of anlioxidation, mithridatism, anlilumor. Melatonin elicits its biological effects principally with high affinity guanine-protein coupled receptor(GRCP). In 1998, MR has been classified into three subtypes as mt1 , MT2, MT3 at IUPHAR congress. The mt1 and MT2 subtypes have been found in mammals including human beings.It has been reported that melatonin can regulate the function of animal thyroid axis and influence the level of thyroid hormone . Therefore, in order to make the active mechanism clear, the problem that whether does there exist melatonin receptors and the subtypes in thyroid should be clarified firstly. Neoplasm is the abnormal hyperplastic tissue when organism have lost normal genetic growth melody devoted to various factor. Although the etiological factor and mechanism of tumor has not illustrated clearly, the theory that patient has low immunity function and can't identify or eliminate the mutation cell lead to the occurrence of tumor has been accepted recently. Although many research revealed the inhibition function on tumor cell by MLT. Little is known about the relationship between MLT with the endocrine tumor. In this study, by several experiment technologies and methods we managed to resolve some questions as follows : 1 . Is there any difference of the concentration of melatonin in the serum between patients with or without thyroid neoplasm? Whether melatonin can be taken as a "mark" to diagnose thyroid neoplasm? 2. Is there anydifference of the concentration of melatonin between homogenate of thyroid neoplasm with peripheral venous blood 3. Are there melatonin receptors in adult human thyroid organs? Which subtypes they are? Where do these subtypes exist in thyroid cell? 4. How about the same problem in patients with thyroid neoplasm? 5. Is there any difference of the concentration of melatonin receptors subtypes between human thyroid neoplasm with normal human thyroid organ? Our destination is supply some new data for the study of the mechanism about how the melatonin impact on human thyroid neoplasm and the possibility used in prevention and cure the neoplasm.Main mathods and results: Part one: Methods: The serum of human peripheral venous blood was obtained from 20 patients with thyroid neoplasm (adenocarcinoma and adenoma) and 10 patients with thyroid disease except thyroid neoplasm (including 2 patients with thydiotitis,7 patients with GD, 1 patient with goiter.). The homogenate was obtained from 7 patients with thyroid adenocarcinoma and 13 patients with thyroid adenoma. The homogenate and the serum were test the concentration of MLT by ELISA. Results: 1. Thyroid neoplasm homogenate had a higher (20 to 400-fold) concentration of MLT than serum (p<0.05~0.01); 2.Patients with thyroid adenocarcinoma neoplasm had a higher concentration of MLT in homogenate. (p<0.05 vs adenoma; p<0.01 vs normal thyroid tissue; p>0.05, adenoma vs normal thyroid tissue). 3.There is no difference of the concentration of melatonin in the serum between patients with or without thyroid neoplasm. Part two: Methods: We sliced up the thyroid neoplasm tissue and normal thyroid tissue 1cm away from neoplasm to detect the melatonin receptor with SP immunohistochemistry method after the slices were fixed, dehydrated and embeded . Results: The slice dyed with the antibody of MT2 receptor antigen had brown granules deposited in the membrane, cytosol and nuclear of the thyroid cell in adenocarcinoma ( + 4- + ) and had a higher intensity than normal thyroid tissue as well as adenoma (±~ + ) . The expression of mt1 in adenocarcinoma (±~ + ) had no significance than adenoma and normal thyr...