A plasma factor inhibiting erythrocyte magnesium efflux.
When incubated at 37 degrees C for 5 h in a magnesium- and calcium-free phosphate buffer solution (PBS), rat and mouse erythrocytes lose 30-40% of their Mg content. However, no Mg loss is observed if these erythrocytes are incubated in their own plasma. In order to investigate this phenomenon, murine erythrocytes were incubated in PBS, in human and murine blood plasmas, and fetal calf serum diluted in PBS (1/4), and in PBS supplemented with MgCl2, CaCl2, and crystallized plasma proteins at concentrations equal to those obtained in plasma/PBS solutions. Erythrocyte Mg efflux was significantly inhibited (P = 10(-8] by diluted human and rat plasmas but the time course of this inhibition was different with these two kinds of plasmas (P = 10(-4]. Mouse plasma and fetal calf serum also entailed a significant inhibition of Mg efflux, while the addition of Mg, Ca, and purified plasma proteins in the incubation medium had little effect. Blood plasma thus contains a factor inhibiting Mg efflux from murine erythrocytes and this effect is not explained by its content of magnesium, calcium, and proteins.
Henrotte
J G
JG
CNRS, Faculté de Pharmacie, Paris, France.
Franck
G
G
Santarromana
M
M
D000818:Animals; D001693:Biological Transport, Active; D004912:Erythrocytes / Q000378:metabolism*; D066298:In Vitro Techniques; D008274:Magnesium / Q000097:blood*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D010949:Plasma / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity
D008274:Magnesium