中文摘要：

目的观察甲状腺组织胃动素前体mRNA的表达和胃动素的定位并探讨其临床意义。方法采用RT—PCR、Southern印迹、荧光免疫组织化学双染等技术，观察人甲状腺胃动素前体mRNA和胃动素免疫活性物（MTL-IR）在甲状腺组织中的表达和分布；并比较胃动素前体mRNA和胃动素在正常甲状腺和甲状腺肿、甲状腺髓样癌组织中表达异同。结果（1）RT—PCR及Southern印迹显示，人甲状腺组织有胃动素前体mRNA的表达。（2）甲状腺组织内有大量胃动素免疫阳性表达的细胞，且胃动素与降钙素共存，即胃动素表达于甲状腺C细胞。（3）甲状腺髓样癌胃动素及其前体mRNA的表达显著高于正常甲状腺组织（P〈0．01）；结节性甲状腺肿与正常甲状腺组织相比胃动素及其前体mRNA的表达差异无统计学意义（P〉0．05）。（4）胃动素蛋白在甲状腺髓样癌中的表达显著增高，但甲状腺肿与正常甲状腺组织相比胃动素蛋白的表达无显著差异。结论甲状腺组织内有胃动素免疫阳性细胞及其前体mRNA的表达，且胃动素与降钙素共表达于甲状腺C细胞；甲状腺髓样癌胃动素及其前体mRNA的表达显著增高；结节性甲状腺肿胃动素及其前体mRNA的表达无明显变化。

英文摘要：

Objective To observe the expression of motilin precursor mRNA and location of motilin in human thyroid and to explore the clinical significance. Methods RT-PCR, Sourthern blot and immunofluorescence histochemical techniques were applied to detect the expressions of motilin precursor mRNA and motilin in human thyroid and to compare the difference of motilin peptide and motilin mRNA expression among tissues of normal thyroid, nodular goiter and medullary thyroid carcinoama. Results （ 1 ） The results of RT-PCR and Southern blot showed that motilin precursor mRNA was expressed in human thyroid. （2） A large number of cells showing collocation of motilin with calcitonin were observed in human thyroid, suggesting that motilin was expressed in C cells. （3） Both the motilin immunoreactive （MTL-IR） and the motilin mRNA were significantly increased in medullary thyroid carcinoma （P 〈 0.01 ） while the expressions of motilin and motilin mRNA in thyroid nodular goiter showed no difference as compared with normal thyroid tissue （P 〉0.05）. （4） Western blot results showed that the expression of motilin in thyroid medullary carcinoma was significantly higher than that in normal thyroid. However no difference was observed between thyroid nodular goiter and normal thyroid tissue. Conclusion MTLIR positive cells and motilin mRNA expression are found in human thyroid. Motilin is located in C cells of thyroid. The expressions of motilin and motilin precursor mRNA are significantly increased in medullary thyroid cancer, no difference between thyroid nodular goiter and normal thyroid tissue.