Alves Glaucie Jussilane, Palermo-Neto João
Laboratory of Applied Pharmacology and Toxicology, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
Neuroimmunomodulation. 2015;22(3):121-9. doi: 10.1159/000358253. Epub 2014 Apr 1.
BACKGROUND/AIMS: This study aimed to verify if odor cues released by Ehrlich tumor-bearing mice are aversive and stressful.
Female mice were divided into a control group and an experimental group. One animal of each experimental pair of mice was inoculated with 5 × 10(6) Ehrlich tumor cells intraperitoneally; the other animal was kept undisturbed and was referred to as a CSP (companion of sick partner). One mouse of each control pair was treated intraperitoneally with 0.9% NaCl (1 mg/kg); the other animal (CHP, companion of healthy partner) was kept undisturbed.
It was shown that, in relation to CHP, CSP mice (1) spent less time within the companion zone in a T-maze place preference test, (2) had increased levels of social interaction, (3) had increased levels of plasmatic adrenaline and noradrenaline and (4) displayed no changes in serum corticosterone levels before and after an immobilization stress challenge. It was also shown that (5) cohabitation with 2 tumor-bearing mice was more effective in decreasing neutrophil oxidative burst than cohabitation with 1 sick partner and (6) the presence of a healthy conspecific within the cage of the tumor-injected/CSP pair abrogated the effects of cohabitation on neutrophil activity. These results show that odor cues released by Ehrlich tumor-injected mice are aversive and induce psychological stress.
We postulate that the aversive response induced by the chemosignals released by Ehrlich tumor-injected animals activates the sympathetic nervous system and causes the neuroimmunal changes that occur in the mice cohabiting with the sick mice.
背景/目的：本研究旨在验证荷艾氏腹水瘤小鼠释放的气味线索是否具有厌恶感并能引起应激反应。
将雌性小鼠分为对照组和实验组。每对实验组小鼠中，一只经腹腔注射5×10(6)个艾氏腹水瘤细胞；另一只保持不受干扰，称为患病伙伴的同伴（CSP）。每对对照组小鼠中，一只经腹腔注射0.9%氯化钠（1mg/kg）；另一只动物（健康伙伴的同伴，CHP）保持不受干扰。
结果表明，与CHP相比，CSP小鼠（1）在T迷宫位置偏好试验中在同伴区域内停留的时间更短，（2）社交互动水平增加，（3）血浆肾上腺素和去甲肾上腺素水平升高，并且（4）在固定应激挑战前后血清皮质酮水平无变化。还表明，（5）与2只荷瘤小鼠同居比与1只患病伙伴同居在降低中性粒细胞氧化爆发方面更有效，以及（6）在注射肿瘤的小鼠/CSP对的笼内有健康同种个体可消除同居对中性粒细胞活性的影响。这些结果表明，注射艾氏腹水瘤小鼠释放的气味线索具有厌恶感并能诱导心理应激。
我们推测，注射艾氏腹水瘤动物释放的化学信号所诱导的厌恶反应激活了交感神经系统，并导致与患病小鼠同居的小鼠出现神经免疫变化。
