Spatial variation of aortic wall oxygen diffusion coefficient from transient polarographic measurements.

摘要: Polarographic current transients following a voltage step (turn-on transient) were measured with bare cathodes (25 μm diameter) and shallowly recessed oxygen microelectrodes (<5μm diameter). Except for the initial part of transient, experimental measurements in excellent agreement simple models literature, which predict an inverse relationship with $$\sqrt t $$ . Turn-on aqueous solutions known physical properties, aortic wall tissue from three different species (n=6 rabbits, n=3 dogs, n=1 miniature pig). Oxygen diffusion coefficients (D) determinedin vitro by comparing time constants same microelectrode saline strips at 37°C. On inner side (endothelium intima) aorta, D averaged (±S.E.) 7.0 (±0.8)×10−6 cm2/s 6 6.4 (±1.0)×10−6 3 was 4.6×10−6 pig. adventitial side, 9.5×10−6 1 rabbit, 11.4 (±1.2)×10−6 8.1×10−6 For every strip on both sides, always lower, overall little more than one third (p<0.001). The lower endothelial may limit transport to vascular play role atherogenesis.