TITLE:
Dopamine D1- and D2-Receptors in Immunostimulation under Activation of Mu-Opioid Receptors in Mice with Different Psychoemotional States
AUTHORS:
Margarita Cheido, Galina Idova, Elizaveta Alperina
KEYWORDS:
Mu-Opioid and Dopamine Receptors; Social Stress; Aggression; Depressive-Like Behavior; Immunomodulation
JOURNAL NAME:
Pharmacology & Pharmacy,
Vol.5 No.1,
January
13,
2014
ABSTRACT:
The purpose of the present study was to analyze the effect of activation of mu-opioid receptors (mu-OR)
on the immune response under blockade
of postsynaptic D1-and D2-receptors in mice of the C57BL/6J strain displaying either aggressive
or depressive-like behaviors in the social conflict model. It is shown
that activation of activation of mu-OR with a highly selective agonist DAGO
(100 μg/kg) increased significantly IgM-immune response not only in C57BL/6J
mice with an unchanged psychoemotional state but also in mice displaying
aggressive or depressive-like behaviors in the social stress model (10 days of
agonistic confrontations). Selective blockade of DA receptors of the D1-type
with SCH-23390 (1.0 mg/kg with DAGO administration) caused a more pronounced
elevation of IgM-immune response than DAGO alone while DAGO effect was
completely blocked by prior administration of D2-receptor antagonist
haloperidol (1.0 mg/kg). At the same time, both SCH-23390 and haloperidol
prevented the immune response increase induced by DAGO injection in mice
engaged in aggressive or depressive-like behaviors. Thus, in animals not
subjected to social stress DAGO-induced immunostimulation is provided only by D2-receptors,
whereas in animals with altered psychoemotional state mu-opioid immunostimulation
is mediated by both types of DA receptors—D1 and D2.
These data provide evidence for different impacts of the main
subtypes of DA receptors in the mediation of immunomodulating effects of
mu-opioid system under normal and stressful conditions.