| dc.description | Objectives: Cohabitation with Ehrlich tumor-bearing (ETB)
mice induced behavioral, neurochemical, hormonal, and immune
effects in the conspecifics as a consequence of stressinduced
activation of the sympathetic nervous system (SNS)
with catecholamine release. In the current study, the nonspecific
??-AR blocker d,l -propranolol and the specific ?? 2 -AR
blocker ICI-118.551 were employed as pharmacological
tools to assess the extent to which catecholamines participated
in the effects induced by cohabitation with ETB mice.
Methods: Two experiments were performed, 1 with d,l -propranolol
treatment and the other with ICI-118.551. One
mouse in the experimental group was called the ???companion of the sick partner??? (CSP) since it was forced to live in the
same cage with 2 (experiment 1) or 1 (experiment 2) cage
mate that had been i.p. injected with 5 ?? 10 6 Ehrlich tumor
cells. Results: The d,l -propranolol treatment, but not the ICI-
118.551 treatment, attenuated the effects of cohabitation
with 2 ETB mice on both open-field behavior and the hypothalamic
levels and turnover rate of norepinephrine. The 2
??-AR blockers were unable to change the serum corticosterone
levels and adrenal weights of the CSP mice; however,
these drugs abrogated the effects of cohabitation on neutrophil
oxidative burst and phagocytosis. Finally, an increase in
the 5-HT turnover rate was observed in the olfactory bulb of
CSP mice compared to their respective controls, an effect
that was not modified by ??-AR blockade. Conclusion: These
results confirm and strengthen our hypothesis that the SNS
is involved in the effects induced by cohabitation with ETB
mice and point towards ?? 2 -AR participation in the immune
effects analyzed. | |
