Chronic amphetamine facilitates immunosuppression in response to a novel aversive stimulus: reversal by haloperidol pretreatment.
The effect of chronic d-amphetamine sulfate (AMPH) treatment (nine daily injections, 2 mg/kg i.p.) on subsequent foot shock stress-induced immunological response was investigated. In addition, the potential role of a dopaminergic (DA) mechanism in the development of chronic AMPH-induced changes in stress-influenced immune responses was characterized. Exposure to foot shock stress decreased the percentage of T-lymphocytes, and reduced the delayed-type hypersensitivity reaction (DTH) in chronically AMPH-pretreated rats relative to vehicle-treated controls. Both of those stress-induced immunosuppressive responses were no longer evident when AMPH-pretreated rats were injected with haloperidol (HAL, 1 mg/kg i.p.) 30 min prior to each daily AMPH injection. The present findings are indicative of a modulatory role for dopamine in the facilitating process induced by AMPH on stress-induced immunosuppressive effects.
Basso
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AM
Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
Gioino
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G
Molina
V A
VA
Cancela
L M
LM
D000661:Amphetamine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D015259:Dopamine Agents / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D006220:Haloperidol / Q000494:pharmacology*; D007165:Immunosuppression Therapy; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology