title: Quantitative changes in the normal and apoptotic thymocytes of pigs treated with anabolic doses of the beta2 adrenergic agonist clenbuterol.
abstract: Although the beta2 adrenergic agonists have been seen to have important effects on the mechanisms regulating the development and death of T-cells in the thymus, the side-effects on the immune system of anabolic treatments of these substances have hardly been considered. In order to evaluate the effects exerted by the beta2 adrenergic agonist clenbuterol on the thymocyte population, the thymus of eight pigs treated with anabolic doses of this substance was studied by morphometric methods, regarding apoptotic (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL)-positive) and normal (TUNEL-negative) cells. The thymus of another eight pigs fed without clenbuterol served as a control. The clenbuterol treatment had a clear effect on the thymocyte size, decreasing their mean nuclear area. The T-cell apoptosis index was also affected by the clenbuterol, significantly increasing the apoptosis percentage in the treated group with respect to the control. In the light of our results, the clenbuterol induced thymocyte apoptosis throughout the thymus and caused morphometric changes in the thymocyte population, which was in line with the immunosuppressive role attributed to other beta2 adrenergic agonists.
authors.affiliation: Department of Comparative Anatomy and Pathological Anatomy, Veterinary Faculty, University of Córdoba, 14075 Córdoba, Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Blanco
authors.forename: Emilio
authors.initials: E
authors.lastname: Artacho-Pérula
authors.forename: Rafaela
authors.initials: R
authors.lastname: Flores-Acuña
authors.forename: Rosario
authors.initials: R
authors.lastname: Moyano
authors.forename: José G
authors.initials: JG
authors.lastname: Monterde
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D002976:Clenbuterol / Q000494:pharmacology*; D007091:Image Processing, Computer-Assisted; D020287:In Situ Nick-End Labeling / Q000662:veterinary; D008297:Male; D011897:Random Allocation; D013552:Swine / Q000276:immunology* / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000276:immunology* / Q000378:metabolism
chemical_list: D000318:Adrenergic beta-Agonists; D002976:Clenbuterol