title: A dopamine mechanism is implied in the acquisition and expression of amphetamine and stress-induced effects observed in the lymphocyte subpopulations.
abstract: Drugs of abuse and stress are associated with changes in circulating cell populations and reductions in cell-mediated immune responses. The main goal of this study was to determine the influence of repeated and acute d-amphetamine treatments on the foot-shock stress-induced effects on the peripheral lymphocyte subpopulations, and the involvement of a dopamine mechanism in the development and expression of this phenomenon. Wistar rats received an acute (5 mg/kg/day i.p.) or a repeated (2 mg/kg/day i.p. during 9 days) amphetamine treatment, and were exposed to a foot-shock stress (1 mA, 3 s) 4 days after the last amphetamine injection. Another group was administered with haloperidol (1 mg/kg/day i.p.) 15 min previous to each daily amphetamine injection or previous to the foot-shock stress session. Then, blood cells stained with monoclonal antibodies against CD3-FITC, CD8-PE and CD4-Cy-Chrome, and against CD161a-FITC, CD3-PE, and CD45RA-Cy-Crhome, were analyzed by multiparameter flow cytometry. The exposure to a foot-shock stress induced a decrease in the absolute number of peripheral lymphocytes, as well as in CD4+ and CD8+ T-cells and B-cells in acute and repeatedly amphetamine-treated rats, whereas the NK-cell population remained unchanged. Haloperidol administration previous to each drug administration or the foot-shock stress session reversed these effects. This study provides strong evidence that dopamine can play a more general role in the influence of amphetamine on the stress-induced effects on the lymphocyte subsets.
authors.affiliation: Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba (UNC), Córdoba, Argentina.
authors.forename: María Amparo
authors.initials: MA
authors.lastname: Assis
authors.forename: Alejandra María
authors.initials: AM
authors.lastname: Pacchioni
authors.forename: César
authors.initials: C
authors.lastname: Collino
authors.forename: María Constanza
authors.initials: MC
authors.lastname: Paz
authors.forename: Claudia
authors.initials: C
authors.lastname: Sotomayor
authors.forename: Ana María
authors.initials: AM
authors.lastname: Basso
authors.forename: Liliana Marina
authors.initials: LM
authors.lastname: Cancela
mesh_terms: D000661:Amphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D015259:Dopamine Agents / Q000008:administration & dosage / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000008:administration & dosage; D015536:Down-Regulation; D005434:Flow Cytometry; D006220:Haloperidol / Q000008:administration & dosage; D007111:Immunity, Cellular / Q000187:drug effects*; D016130:Immunophenotyping / Q000379:methods; D007274:Injections, Intraperitoneal; D016131:Lymphocyte Subsets / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000276:immunology / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D000697:Central Nervous System Stimulants; D015259:Dopamine Agents; D018492:Dopamine Antagonists; D000661:Amphetamine; D006220:Haloperidol; D004298:Dopamine