3.0 Gy X线全身照射后对大鼠下丘脑—垂体—肾上腺皮质系统应激反应的影响

本文报道了3.0 GyX线全身照射后1、3日大鼠下丘脑—垂体—肾上腺皮质系统对应激刺激(一侧后肢骨折)的反应性变化。正常大鼠受应激刺激后10min,血浆β—EP、皮质酮、肾上腺和垂体的cAM P及下丘脑M—EnK水平都明显升高,而下丘脑β—EP含量则显著降低。照射后1日未应激组,血浆β—EP、皮质酮和垂体cAMP水平均显著高于正常对照,下丘脑β—EP也明显低于正常对照。照后1日应激组各参数虽明显高于正常对照,但与未应激组相比,除肾上腺cAMP和下丘脑B—EP水平显著升高外,其余各参数均差异不显著。照后3日未应激组,各参数都回降到接近正常水平。照后3日应激与未应激组相比,6项参数有4项显著增高,其余血浆皮质酮和下丘脑B—EP 2项虽有升高但差异不显著。结果表明,3.0GyX射线全身照射基本上未降低机体对应激的适应能力。

Effect of 3.0 Gy whole body X-irradiation on stress-response of hypothalamo-pituitary-adrenocortical system in rats

Changes in response of hypothalamo-pitultary-adrenocortical system to stress (right tibiofibular fracture) was investigated 1 and 3 days after whole body X-irradiation at a dose of 3.0Gy.It was shown that at 10 min after strrss in normal rats the levels ofB-endorphin (beta-EP) and corticosterone in plasma, cAMP in adrenal and pituitary fglands, and met-enkephalin (M-Enk) in hypothalamus were significantly increased. When compared with the control 1 day after irradiation, the levels of plasma beta-EP, corticosterone and cAMP in pituitary gland were significantly higher, while beta-EP in hypothalarnus was significantly lower .Except for adrenal cAMP and hypo-thalamic beta-EP, no significant changes were found among other parameters between irradiated rats with and without stress. These changes recovered to normal levels 3 days after Irradiation in rats without stress, but remained increased in rats with stress. It was demonstrated that adaptation of the organism to stress was not affected basically by whole body X-irradiation at a dose of 3 .0Gy.