We have investigated experimentally the magnetization of low-dimensional electron systems in quantum wire arrays fabricated in modulation-doped AlGaAs/GaAs heterostructures. Periodic arrays with different electronic width of the wires ranging from 160 to have been studied. We observe magnetization oscillations which are surprisingly close to a sawtooth profile, however exhibit an increasing width of the negative flanks for the narrow wires. We argue that this profile directly reflects the effective screening of the external confinement potential due to the electron–electron interaction and the E−1/2 density of states in the quantum wires, respectively.