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Transport mechanisms for iron and other transition metals in rat and rabbit erythroid cells
Author(s) -
Savigni Donna L.,
Morgan Evan H.
Publication year - 1998
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.1998.837bp.x
Subject(s) - chemistry , biophysics , transition metal , metal , heavy metals , biochemistry , biology , environmental chemistry , catalysis , organic chemistry
1 Earlier studies have shown that Fe 2+ transport into erythroid cells is inhibited by several transition metals (Mn 2+ , Zn 2+ , Co 2+ , Ni 2+ ) and that Fe 2+ transport can occur by two saturable mechanisms, one of high affinity and the other of low affinity. Also, the transport of Zn 2+ and Cd 2+ into erythroid cells is stimulated by NaHCO 3 and NaSCN. The aim of the present investigation was to determine whether all of these transition metals can be transported by the processes described for Fe 2+ , Zn 2+ and Cd 2+ and to determine the properties of the transport processes. 2 Rabbit reticulocytes and mature erythrocytes and reticulocytes from homozygous and heterozygous Belgrade rats were incubated with radiolabelled samples of the metals under conditions known to be optimal for high‐ and low‐affinity Fe 2+ transport and for the processes mediated by NaHCO 3 and NaSCN. 3 All of the metals were transported by the high‐ and low‐affinity Fe 2+ transport processes and could compete with each other for transport. The K m and V max values and the effects of incubation temperature and metabolic inhibitors were similar for all the metals. NaHCO 3 and NaSCN increased the uptake of Zn 2+ and Cd 2+ but not the other metals. 4 The uptake of all of the metals by the high‐affinity process was much lower in reticulocytes from homozygous Belgrade rats than in those from heterozygous animals, but there was no difference with respect to low‐affinity transport. 5 It is concluded that the high‐ and low‐affinity ‘iron’ transport mechanisms can also transport several other transition metals and should therefore be considered as general transition metal carriers.