title: β2-agonist clenbuterol suppresses bacterial phagocytosis of splenic macrophages expressing high levels of macrophage receptor with collagenous structure.
abstract: Splenic marginal zone macrophages expressing macrophage receptor with collagenous structure (MARCO) contribute to the clearance of blood-borne pathogens. We determined a splenic adherent cell fraction abundantly containing cells expressing a higher level of MARCO by flow cytometry, and examined the effects of daily administration of an anabolic dose of β2-agonist clenbuterol on the phagocytic capacity of the cells in mice. After 6 weeks of clenbuterol (1.0 mg/kg body weight/d) or vehicle administration to the mice, splenic adherent cells were isolated. These cells were separated into three cell-size subpopulations. Among them, the small-cell subpopulation contained abundantly the cells with markedly higher levels of MARCO and exhibited more intense phagocytic capacity against Escherichia coli, as compared with the other subpopulations. The phagocytic capacity of the small cells was significantly reduced after clenbuterol administration. These results suggest that the utilization of clenbuterol as doping drug impairs bacterial clearance in the spleen.
authors: Laboratory of Physiological Sciences, Faculty of Human Sciences, Waseda University, 2–579–15 Mikajima, Tokorozawa, Saitama 359– 1192, Japan. shirato@aoni.waseda.jp
authors: Ken
authors: K
authors: Shirato
authors: Shogo
authors: S
authors: Sato
authors: Madoka
authors: M
authors: Sato
authors: Yoko
authors: Y
authors: Hashizume
authors: Kaoru
authors: K
authors: Tachiyashiki
authors: Kazuhiko
authors: K
authors: Imaizumi
mesh_terms: D058666:Adrenergic beta-2 Receptor Agonists / Q000494:pharmacology*; D000818:Animals; D002976:Clenbuterol / Q000494:pharmacology*; D008264:Macrophages / Q000737:chemistry / Q000187:drug effects* / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010587:Phagocytosis / Q000187:drug effects*; D011971:Receptors, Immunologic / Q000032:analysis* / Q000502:physiology; D013154:Spleen / Q000276:immunology
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; C092228:Marco protein, mouse; D011971:Receptors, Immunologic; D002976:Clenbuterol