title: The anemia of microgravity and recumbency:  role of sympathetic neural control of erythropoietin production.
abstract: We hypothesize that reduced sympathetic stimulation of erythropoietin production may maintain the anemia which develops in virtually all space travellers. We tested this hypothesis in a human model of reduced sympathetic activity. Thirty-three patients with the Bradbury-Eggleston syndrome were divided into three groups according to their hemoglobin (Hgb) level. Patients with low Hgb had lower upright norepinephrine and lower upright renin. Patients with anemia also had inappropriately low plasma erythropoietin levels. We administered recombinant erythropoietin (Epogen) 25-50 units/kg s.c. 3 times per week and found that the anemia seen in autonomic failure could be reversed by this treatment. These results support the hypothesis that erythropoiesis is modulated by the sympathetic nervous system and that at such mechanisms may also operate in the microgravity environment where sympathetic activity is reduced.
authors.affiliation: Center for Space Physiology and Medicine, Departments of Medicine and Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-2195, USA.
authors.forename: D
authors.initials: D
authors.lastname: Robertson
authors.forename: S B
authors.initials: SB
authors.lastname: Krantz
authors.forename: I
authors.initials: I
authors.lastname: Biaggioni
mesh_terms: D000740:Anemia / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology*; D002395:Catecholamines / Q000378:metabolism; D000068817:Epoetin Alfa; D004911:Erythrocyte Volume; D004920:Erythropoiesis / Q000502:physiology*; D004921:Erythropoietin / Q000378:metabolism* / Q000627:therapeutic use; D006801:Humans; D007024:Hypotension, Orthostatic / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D011187:Posture; D011994:Recombinant Proteins; D012083:Renin / Q000097:blood; D013026:Space Flight; D013564:Sympathetic Nervous System / Q000502:physiology*; D014893:Weightlessness / Q000009:adverse effects
chemical_list: D002395:Catecholamines; D011994:Recombinant Proteins; D004921:Erythropoietin; D000068817:Epoetin Alfa; D012083:Renin