Sandi C, Cambronero J C, Borrell J, Guaza C
Psychobiology Research Group, Cajal Institute, CSIC, Madrid, Spain.
Brain Res Bull. 1992 Apr;28(4):581-5. doi: 10.1016/0361-9230(92)90106-8.
Acute stress-induced immune alterations can result in adapted function with prolonged exposure to the same stressor. The present study was designed to evaluate the possible role of the hypothalamic-pituitary-adrenocortical (HPA) axis on the adaptation of spleen lymphocyte responsiveness to repeated stress. For this purpose, we selected a stressful protocol (aversive auditory stimulation) that induced an initial suppression (1 day), followed by a return to control values with repeated application (4 days), of mitogen-induced lymphocyte proliferation. Because rats exposed to 4 days of noise sessions show enhanced adrenocorticotropin (ACTH) and corticosterone levels, we tested the possibility that adaptation of lymphoproliferation by repeated stress was due to a desensitization of splenic lymphocytes to stress-released HPA hormones. The results showed that corticotropin-releasing factor (10(-9) M) and corticosterone (5 x 10(-8) and 10(-7) M), as well as dexamethasone (10(-8), 5 x 10(-8), and 10(-7) M), significantly suppressed lymphoproliferation from both control and stressed rats in a similar way. ACTH (10(-9) and 5 x 10(-9) M) did not significantly influence Concanavalin-A-stimulated spleen lymphocytes. These data indicate that adaptation of lymphocyte proliferation by repeated noise stress occurs without accompanying alterations in lymphocyte responsiveness to HPA hormones.
急性应激诱导的免疫改变在长期暴露于同一应激源时可导致适应性功能。本研究旨在评估下丘脑 - 垂体 - 肾上腺皮质（HPA）轴在脾脏淋巴细胞反应性对重复应激的适应性方面可能发挥的作用。为此，我们选择了一种应激方案（厌恶性听觉刺激），该方案诱导最初的抑制（1天），随后随着重复应用（4天）丝裂原诱导的淋巴细胞增殖恢复到对照值。由于暴露于4天噪声刺激的大鼠显示促肾上腺皮质激素（ACTH）和皮质酮水平升高，我们测试了重复应激导致淋巴细胞增殖适应性的可能性是否是由于脾淋巴细胞对应激释放的HPA激素脱敏所致。结果表明，促肾上腺皮质激素释放因子（10^(-9) M）、皮质酮（5×10^(-8)和10^(-7) M）以及地塞米松（10^(-8)、5×10^(-8)和10^(-7) M）以类似方式显著抑制了对照大鼠和应激大鼠的淋巴细胞增殖。ACTH（10^(-9)和5×10^(-9) M）对伴刀豆球蛋白A刺激的脾脏淋巴细胞没有显著影响。这些数据表明，重复噪声应激导致淋巴细胞增殖的适应性发生时，淋巴细胞对应激激素的反应性并未伴随改变。
