Magnesium transport in ferret red cells.

Intracellular Mg2+ regulation in voltage‐clamped Helix aspersa neurones measured with mag‐fura‐2 and Mg(2+)‐sensitive microelectrodes

“…However, evidence for a Na'-Mg2+ exchanger in ventricular myocytes is contradictory. Buri & McGuigan, (1990) and Buri et al (1993) (F&ray & Garay, 1986;Flatman & Smith, 1990). Thus the increase in [Mg2+]i seen in these experiments may be due to a partial inhibition of a Na+-Mg2+ exchanger by Ca2+.…”

“…This ligalnd has been shown to be much less sensitive than ETH 111 7 to changes in Na1 and K+ and is una1ffected by Ca12+ less than 20 ,UM (Buni & MeGuigaln, 1993t0 (Baker & Crawford, 1972;De Weer, 1976;Caldwell-Violich & Requena, 1979 (Gunzel & Schlue, 1996 and red blood cells (Feray & Garay, 1986;Flatman & Smith, 1990;Gunther, Vormann & Hollriegel, 1990). However, evidence for a Na'-Mg2+ exchanger in ventricular myocytes is contradictory.…”

“…More recently, Giinzel & Schlue (1996 have demonstrated a Na _Mg2+ exchanger in invertebrate neurones. Na'-Mg2" exchangers have been demonstrated in red blood cells (Feray & Garay, 1988;Frenkel, Graziani & Schatzmann, 1989;Flatman & Smith, 1990;Gunther, Vorman & H6llriegel, 1990). In ferret and guinea-pig ventricular muscle, Buri & McGuigan (1990) and Buri et al (1993) concluded that Mg2' efflux does not occur via Na'-Mg2+ exchange.…”

Regulation by extracellular Na+ of cytosolic Mg2+ concentration in Mg2+‐loaded rat sublingual acini

“…types, including parotid gland cells [6], have Mg2+-ATPase, however, this activity is unrelated to Mg 2+ transport. Na+/Mg 2+ antiport is found in several cell types [3,[7][8][9][10][11][12]. This Mg 2+ efflux system is sensitive to quinidine [10,13], Mn 2÷ and tricyclic antidepressant drugs [14].…”

High extracellular [Mg2+]‐induced increase in intracellular [Mg2+] and decrease in intracellular [Na+] are associated with activation of p38 MAP kinase and ERK2 in guinea‐pig heart

“…Those effects could result from Mg 2+ antagonism of the Na + channel (Kline et al 1994) and Ca 2+ current (Watts et al 1998). Another possibility is an inhibition of the (Flatman & Smith, 1990;Buri et al 1993;Gunther & Holleigl, 1993;Watanabe et al 1998;Schweigel et al 2000;Tashiro et al 2002;McGuigan et al 2002;Romani, 2007) as well as to inhibit Mg 2+ influx by the reverse mode of Na + -Mg 2+ exchange (Flatman & Smith, 1991). In this study, we clearly determined that the high [Mg 2+ ] o resulted in a concentration-dependent reduction ] o are far from the physiological blood magnesium concentration of the guinea-pig (<1 mM; Scheibe et al 1999), although a high Mg 2+ concentration in blood has been shown to occur after stress by noise (∼4 mM; Scheibe et al 1999), during hibernation in turtles (11.7 mM, versus 2.6 mM in the active period; Reese et al 2000), in hibernating mammals (29-62% increase; Riedesel & Folk, 1956) and after acute extreme exercise in humans (13% increase; Cordova, 1992).…”