甲状腺素对大鼠实验性自体免疫心肌炎的作用

实验选用清洁级F344/NSIc大鼠，腹腔内注射甲状腺素（10μg/100g体重），观察甲状腺素对肌球蛋白诱导的实验性自体免疫心肌炎的作用，并用免疫荧光技术结合流式细胞仪分析甲状腺素对免疫反应的影响。结果显示，甲状腺素对肌球蛋白免疫所致的心肌坏死，炎性细胞浸润和纤维化没有明显的改善作用；甲状腺素可诱导外周血B淋巴细胞比例升高。但对辅助T细胞和抑制T细胞比例。辅助T细胞/抑制T细胞比率没有影响。

EFFECTS OF THYROID HORMONE ON EXPERIMENTAL AUTOIMMUNE MYOCARDITIS IN RATS

The effects of thyroid hormone on experimental autoimmune myocarditis (EAM) were evaluated in rats. EAM was induced by immunization with cardiac myosin. Thyroid hormone (3,3',5 triiodo L thyronine) was administrated by intraperitoneal injection of 10ug/100g body weight. The histopathological changes of the heart were estimated by light microscopy. The changes of lymphocyte subsets in peripheral blood were assayed using immunofluorescence technique with a flow cytometer. Immunization with cardiac myosin elicited mild severe myocarditis in rats characterized by extensive myocardial necrosis, infiltration of inflammatory cells and fibrosis. No obvious histopathological differences were observed between hyperthyroid rats immunized with cardiac myosin and the rats immunized with cardiac myosin only. Thyroid hormone administration induced an increase in the percentage of B lymphocyte ( P <0 05) but did not alter the normal balance between helper and suppressor T cell. Our results indicate that thyroid hormone administration can enhance humoral immune response and not interfere with the progression of EAM.