title: Human red cells from prenatal stages of hemopoiesis. Lithium flux components.
abstract: Red cells from umbilical cord with increased lithium content were submitted to different experimental conditions in order to study lithium flux components. There appeared three components: First, an ouabain-sensitive component, related to Na+ replacement with Li+ in the primary active Na+/K+ transport system. The magnitude of this fraction is greater than in adults' red cells. Second, an outside sodium-dependent Li+ efflux fraction, corresponding to the Li+/Na+ countertransport system with Vmax and K(m) values of 0.1 (mmol/l cells.h) and 2.58 (mmol/l), respectively. The Na+o-affinity for lithium efflux in this system is greater in neonatal than in adults' red cells. Third, a leak fraction with an equal value to that reported in adults' red cells. Furthermore, the possible non-existence of a bumetanide-sensitive lithium flux fraction was shown in neonatal red cells.
authors.affiliation: Cátedra de Fisiología, Facultad de Ciencias Médicas, Argentina.
authors.forename: J L
authors.initials: JL
authors.lastname: Corchs
authors.forename: G
authors.initials: G
authors.lastname: Mujica
authors.forename: R E
authors.initials: RE
authors.lastname: Serrani
mesh_terms: D000328:Adult; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006400:Hematocrit; D006410:Hematopoiesis; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008094:Lithium / Q000097:blood*; D012964:Sodium / Q000097:blood
chemical_list: D008094:Lithium; D012964:Sodium