Cohabitation with a Sick Cage Mate: Effects on Ascitic Form of Ehrlich Tumor Growth and Macrophage Activity

Abstract

The present study was designed to evaluate the effects of mice cohabitation with a sick conspecific cage mate on peritoneal macrophage activity and on resistance to Ehrlich tumor growth. Female mice housed in pairs were divided into control and experimental groups. One mouse of each control pair was inoculated with NaCl (0.1 ml/10 g) intraperitoneally and the other, called ‘companion of healthy partner’ (CHP), was kept undisturbed. One animal of each experimental pair of mice was inoculated with 5.0 × 10⁶ Ehrlich tumor cells intraperitoneally and the other, the subject of this study, was called ‘companion of sick partner’ (CSP). Peritoneal macrophages were removed from CSP and CHP mice to analyze resident macrophage activity (experiment 1), macrophage activity after Mycobacterium bovis (experiment 2) or Ehrlich tumor cells (experiment 3) in vivo inoculations. The resistance of CSP and CHP mice to Ehrlich tumor growth was also analyzed (experiment 4). Differences between groups were not found on resident macrophage activity. However, Onco-BCG- and Ehrlich tumor-activated macrophages from CSP mice presented a decreased intensity and percentage of phagocytosis and an increased respiratory burst in the presence of Staphylococcus aureus stimulation in vitro. CSP animals at the same time displayed a decreased resistance to Ehrlich tumor growth. These data were discussed in light of a possible psychological stress effect imposed by the housing condition on mice’s peritoneal macrophage activity and, as a consequence, on their resistance to Ehrlich tumor growth.

Effect of cyhalothrin on Ehrlich tumor growth and macrophage activity in mice

“…Physical and psychological stressors have been reported to decrease resistance to Ehrlich tumor (4,7,9). A decreased resistance to mammary tumor growth and its response to chemotherapy have also been reported in stressed mice (29).…”

“…Accordingly, a variety of stressors have been found to alter immune responses in experimental animals. An inescapable foot shock and a psychological stressor generated with the use of a communication box were shown to concomitantly alter stress levels, macrophage activity, and Ehrlich tumor growth in mice (4); sound stress suppressed the T-and B-cell mediated responses in rats (5); inescapable foot shocks increased total alveolar cell count in OVA-sensitized rats (6); individual housing induced an altered immuneendocrine response and, at the same time, decreased resistance to Ehrlich tumor growth (7); submissive mice displayed more anxiety-like behaviors and decreased macrophage activity, and showed a decrease in resistance to implantation and development of melanoma metastases in their lungs (8); stress induced by cohabitation with sick partners decreased macrophage activity (9) and dendritic cell phenotype (10).…”

Aspectos neuroimunológicos do ecstasy (N-metil-3,4-Metilenodioximetanfetamina-MDMA), na inflamação alérgica pulmonar em camundongos Balb/C.

“…De fato, em nossos laboratórios, verificou-se que animais ansiosos e/ou deprimidos, por estimulação aversiva, apresentaram alterações na imunidade (PALERMO-NETO; SOUZA, 2003). Também foram demonstradas alterações no comportamento e na imunidade de camundongos cujas mães receberam um estresse pré-natal (FONSECA; ; mostou-se também, que o estresse reduziu a atividade de células Natural Killer (NK), a atividade de macrófagos e de neutrófilos, a proliferação de linfócitos T e B, alterações estas assossiadas a uma redução da resistência a infecções e a neoplasias nos animais de laboratório (ALVES et al, 2007;MORGULIS et al, 2004;PALERMO-NETO et al, 2008;QUEIROZ et al, 2008;SA-ROCHA et al, 2006).…”

“…No mesmo sentido, camundongos machos submissos apresentavam elevados níveis de ansiedade, reduzida atividade de células NK e aumento das metástases pulmonares induzidas pelo implante de um melanoma, B16/F10, quando comparados com os animais dominantes . Em outro estudo, observou-se que animais estressados por conviverem com companheiros doentes apresentaram um aumento no turnover de noradrenalina hipotalâmica, reduzida atividade de macrófagos e aumento do crescimento do tumor ascítico de Ehrlich (ALVES et al, 2006;ALVES et al, 2007); estes animais mostraram ainda, um déficit na maturação de células dendríticas e no desenvolvimento de uma hipersensibilidade do tipo tardio induzida por ovalbumina (TOMIYOSHI et al, 2009). …”

Efeitos dos ligantes de TSPO sobre a migração leucocitária: participação de receptores de glicorticóides

“…Estudos recentes têm mostrado que estados emocionais, como depressão, estresse e ansiedade (SA-ROCHA et. al., 2006;ALVES et., al., 2006ALVES et., al., , 2008PINHEIRO et. al., 2011) bem como medicamentos de ação central, como o diazepam (MASSOCO; LAZZARINI et., al., 2001LAZZARINI et., al., , 2006SILVA et.…”