title: Circadian rhythms in surface molecules of rat blood lymphocytes.
abstract: The present article examines whether the expression of certain surface molecules that trigger immune responses shows a circadian rhythm. We also analyzed the rhythms in the number and percentage of lymphocyte subpopulations, in the leukocyte differential counts, and in the total red and white blood cell counts. Blood samples obtained from rats at 2-h intervals for 24 h were stained with several mouse monoclonal antibodies directed against lymphocyte surface molecules and processed by flow cytometry. The number of B, total T, Tgammadelta, Th, and Ts/c cells followed a 24-h rhythm with a peak in the first half of the resting period. The expression of CD45, CD5, CD3, and CD4 followed a circadian rhythm. Their acrophases suggested temporal association between CD45 and CD5 at the end of the active phase and between CD4 and CD3 at the beginning of this phase. This temporal organization could have an important role for immune cell function.
authors.affiliation: Grup d'Autoimmunitat i Tolerància, Departament de Fisiologia-Divisió IV, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain. cpelegri@farmacia.far.ub.es
authors.forename: Carme
authors.initials: C
authors.lastname: Pelegrí
authors.forename: Jordi
authors.initials: J
authors.lastname: Vilaplana
authors.forename: Cristina
authors.initials: C
authors.lastname: Castellote
authors.forename: Manel
authors.initials: M
authors.lastname: Rabanal
authors.forename: Angels
authors.initials: A
authors.lastname: Franch
authors.forename: Margarida
authors.initials: M
authors.lastname: Castell
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000097:blood*; D002940:Circadian Rhythm / Q000502:physiology*; D008214:Lymphocytes / Q000097:blood*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D015703:Antigens, CD