Safieh-Garabedian B, Kanaan S A, Jalakhian R H, Poole S, Jabbur S J, Saadé N E
Department of Biology, Faculty of Arts and Sciences, American University of Beirut, Lebanon.
J Neuroimmunol. 1997 Mar;73(1-2):162-8. doi: 10.1016/s0165-5728(96)00195-6.
Thymulin injection into rats (20-150 ng) i.p. caused a significant reduction in both mechanical (paw pressure test) and thermal (hot plate and tail flick tests) nociceptive thresholds. Thymulin injection also doubled IL-1beta level in the liver of these animals. Induced hyperalgesia was reversed completely by alpha-MSH related tripeptide, Lys-D-Pro-Val in low doses, which is known to antagonize IL-1beta and PGE2 induced hyperalgesia, but was only partly reversed by IL-1beta related tripeptide, Lys-D-Pro-Thr at high doses, which is known to antagonize IL-1beta induced hyperalgesia only. We conclude from these results that thymulin causes hyperalgesia and that this effect is at least in part mediated via PGE2 and its effectiveness at low concentration implies a physiological role for this thymic hormone.
腹腔注射胸腺素（20 - 150纳克）到大鼠体内，会导致机械性（爪部压力测试）和热性（热板和甩尾测试）伤害性感受阈值显著降低。胸腺素注射还使这些动物肝脏中的白细胞介素-1β水平加倍。低剂量的与α-促黑素相关的三肽Lys-D-Pro-Val可完全逆转诱导的痛觉过敏，已知该三肽可拮抗白细胞介素-1β和前列腺素E2诱导的痛觉过敏，但高剂量的与白细胞介素-1β相关的三肽Lys-D-Pro-Thr只能部分逆转痛觉过敏，已知该三肽仅拮抗白细胞介素-1β诱导的痛觉过敏。从这些结果我们得出结论，胸腺素会引起痛觉过敏，且这种作用至少部分是通过前列腺素E2介导的，其在低浓度时的有效性意味着这种胸腺激素具有生理作用。
