the central effect of biological amines on immunosuppressive effect of restraint stress in rat

the effects of some histaminergic agents were evaluated on stress- induced immunosuppression in immunized nale rats. in rat immunized with sheep red blood cells ( srbcs). restraint stress (rs) prevented the booster-induced rise in anti-srbc antibody titre and cell immunity response. intracerebroventicular (i.c>v) injection of histamine (150 µg/rat) induced a similar effect with rs. pretreatment with chlorpheniramine (50 µg/rat) reduced the inhibitory effect of ras on immune function. also histamine could inhibit the effect of rs on immune function. also histamine could inhibitory the effect of chlorpheniramine when injected simultaneously. pretreatment with ranidine (10 µg/rat) had not a significant effect. serotonin (3 µg/rat) and dopamine (0.2 µg/rat) could reverse the effects of chlorpheniromine when injected with chlorpheniramine (p<0.05). epinephrine (0.2 µg/rat) had not a significant effect. the results indicate that histamine mediates the immunosuppression of restraint stress by influencing the histamine h1 receptor in the brain and this effects of histamine may be modulated by serotoninergic and dopaminergic system.