猪垂体不同剂量照射后血清激素和靶腺器官的反应

Serum hormone and target organ response after irradiation of porcine pituitary with various doses

目的 :探讨垂体不同单次剂量照射后的放射反应。方法 :采用依附于LINAC的SRS系统对幼年小型猪垂体一次施照 ,观察照射后血清睾酮、T3 、T4、皮质醇水平的动态变化 ,并对垂体及其靶腺器官进行组织学观察。结果 :照射后血清睾酮水平的降低出现最早 ,15Gy以下组在观察期末出现不同程度恢复 ,2 0Gy组血清睾酮和T4在实验后期呈持续低水平 ,血清T3 和皮质醇水平未出现改变。结论 :垂体腺分泌细胞具有不同的放射敏感性 ,5Gy照射即可抑制促性腺激素分泌细胞 ,但 15Gy照射后仍能部分恢复。对于单次 2 0Gy的剂量照射 ,ACTH分泌细胞有较好的耐受 ,促甲状腺素 (TSH)

Objective:To study the radiation response of the pituitary to single dose irradiation.Methods:The porcine hypophysis was irradiated by single doses with the LINAC SRS system. The serum levels of testosterone,T 3,T 4 and cortisol were mea sured. At the 40 weeks after irradiation, pituitary, testes, thyroids and adrenals were obtained for histopathological examination.Results:The results showed that the serum testosterone levels first declined in all irradiated groups, but recovered in different degree in 5-15Gy groups. In the late stage, the decline of the 20Gy group’s T 4 and testerone levels sustained .No significant changes in T 3 and cortisol levels were found. Conclusion:It suggests that there are different radiative sensitivity among the pituitary endocrine cells. 5Gy irradiation could restain FSH production, but this ability could partly recover even after 15Gy irradiation. After 20Gy single dose irradiation, ACTH-producting cells could maintain normal function, while TSH producting cells should be slightly inhibited.