不同剂量照射后猪垂体内分泌功能的放射损伤(英文)

Endocrine function injury of porcine pituitary after irradiation 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:采用依附于电子直线加速器的立体定向照射系统对幼年小型猪垂体一次施行照射,观察照射后血清睾酮、T3、T4、皮质醇水平的动态变化。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,20Gy组血清睾酮和T4在实验后期呈持续低水平(F=2.57,P>0.05),血清T3和皮质醇水平未出现改变(F=1.96,P>0.05)。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20Gy的剂量照射,促肾上腺皮质激素分泌细胞有较好的耐受,促甲状腺素分泌细胞轻度受抑。

AIM:To find out the radiation reaction of the pituitary after the different single dose irradiation. METHODS:The juvenile porcine hypophysis was irradiated by single doses with the Stereotactic Radiation System(SRS) adhered to Linear Accelerator(LINAC).Dynamic changes of serum levels of testosterone,triiodothyronine(T3), thyroxine(T4) and cortisol were measured. RESULTS:The results showed that the serum testosterone levels declined first in all irradiated groups,but recovered in different stages below 15 Gy groups during the observation period. In the late period of experiment,the serum testosterone and T4 in the 20 Gy group were continuously kept at low level(F=2.57,P >0.05).No significant changes in T3 and cortisol levels were found(F=0.96,P >0.05). CONCLUSION:There are different radiation sensitivities among the pituitary endocrine cells.5 Gy irradiation can restrain gonadotropic hormone from secreting cells,but this ability can partly recover after 15 Gy irradiation.For 20 Gy single dose irradiation,adrenocorticotropic hormone(ACTH) secreting cells can maintain well,while thyroid stimulating hormone(TSH) secreting cell was slightly inhibited.