Effect of lead on the calcium transport in human erythrocyte.
In this paper we study the calcium uptake in the erythrocyte, a non-excitable cell. This uptake is performed through a passive transport system with two kinetic components (Michaelis-Menten and Hill). The uptake of calcium seems to be driven by voltage through its electrophoretical effect. Lead is capable of inhibiting calcium uptake in a non-competitive manner. As it has been described in other systems, lead is also capable of inhibiting calcium efflux by inhibiting Ca(Mg)-ATPase. Under physiological conditions, the function of ATPase reduces the effect of lead on calcium influx. However, in chronic intoxication a small increment of intracellular calcium is observed, indicating that lead is affecting calcium efflux mainly. We discuss the effects of lead on calcium equilibrium in erythrocytes.
Calderón-Salinas
J V
JV
Department of Biochemistry, CINVESTAV-IPN, México City, México.
Quintanar-Escorza
M A
MA
Hernández-Luna
C E
CE
González-Martínez
M T
MT
D000328:Adult; D001692:Biological Transport; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007854:Lead / Q000494:pharmacology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D011188:Potassium / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology
D004791:Enzyme Inhibitors; D014268:Trifluoperazine; D007854:Lead; D017301:Ca(2+) Mg(2+)-ATPase; D011188:Potassium; D002118:Calcium