The effects of spaceflight on adrenergic receptors and agonists and cell adhesion molecule expression.
Twenty-two astronauts who flew aboard 10 different US Space Shuttle flights were studied 10 days before launch, on landing day, and 2-4 days post-landing. After landing, plasma levels of norepinephrine (p<0.01) were elevated. Lymphocyte beta(2)-adrenergic receptors were desensitized 2-4 days post-landing (p<0.02). The density of CD62L on lymphocytes was unchanged but the densities of CD11a (p<0.01) and CD54 (p<0.001) were down-regulated. CD11a density was also down-regulated on monocytes (p<0.01). Neutrophils showed an up-regulation of CD11a (p<0.01) and a down-regulation of CD54 (p<0.01). CD11a density on neutrophils remained up-regulated (p<0.01) and CD54 density remained down-regulated (p<0.01) at 2-4 days post-landing. Circulating levels of soluble ICAM-1 (CD54) and soluble E-selectin (CD62E) were decreased after landing (p's<0.05). The data suggest that spaceflight leads to an environment that would support reduced leukocyte-endothelial adhesion. Sympathetic activation may contribute to this phenomenon.
Mills
Paul J
PJ
Department of Psychiatry and Medicine, University of California, San Diego, La Jolla, CA 92103, USA. pmills@ucsd.edu
Perez
Christy J
CJ
Adler
Karen A
KA
Ziegler
Michael G
MG
D040881:CD11a Antigen / Q000097:blood; D015815:Cell Adhesion Molecules / Q000097:blood*; D019040:E-Selectin / Q000097:blood; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D019041:L-Selectin / Q000097:blood; D007958:Leukocyte Count; D008297:Male; D009638:Norepinephrine / Q000097:blood*; D018343:Receptors, Adrenergic, beta-2 / Q000032:analysis*; D013026:Space Flight; D013564:Sympathetic Nervous System / Q000502:physiology
D040881:CD11a Antigen; D015815:Cell Adhesion Molecules; D019040:E-Selectin; D018343:Receptors, Adrenergic, beta-2; D018799:Intercellular Adhesion Molecule-1; D019041:L-Selectin; D009638:Norepinephrine