Li influx and binding, and li/mg competition in bovine chromaffin cell suspensions as studied by li NMR and fluorescence spectroscopy.
Met Based Drugs
; 7(6): 357-64, 2000.
Article
en En
| MEDLINE
| ID: mdl-18475968
Li(+) influx by bovine chromaffin cells, obtained from bovine adrenal medulla, was studied in intact cell suspensions using (7)Li NMR spectroscopy with the shift reagent [Tm(HDOTP)](4-). The influx rate constants, k(i), were determined in the absence and in the presence of two Na(+) membrane transport inhibitors. The values obtained indicate that both voltage sensitive Na(+) channels and (Na(+)/K(+))-ATPase play an important role in Li(+) uptake by these cells. (7)Li NMR T(1) and T(2) relaxation times for intracellular Li(+) in bovine chromaffin cells provided a T(1)/T(2) ratio of 305, showing that Li(+) is highly, immobilized due to strong binding to intracellular structures. Using fluorescence spectroscopy and the Mg(2+) fluorescent probe, furaptra, the free intracellular Mg(2+) concentration in the bovine chromaffin cells incubated with 15 mM LiCl was found to increase by about mM after the intracellular Li(+) concentration reached a steady state. Therefore, once inside the cell, Li(+) is able to displace Mg(2+) from its binding sites.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Met Based Drugs
Año:
2000
Tipo del documento:
Article
Pais de publicación:
Estados Unidos