title: A new method for measuring the oxygen diffusion constant and oxygen consumption       rate of arteriolar walls.
abstract: Oxygen transport is believed to primarily occur via capillaries and depends on the oxygen tension gradient between the vessels and tissues. As blood flows along branching arterioles, the O(2) saturation drops, indicating either consumption or diffusion. The blood flow rate, the O(2) concentration gradient, and Krogh's O(2) diffusion constant (K) of the vessel wall are parameters affecting O(2)delivery. We devised a method for evaluating K of arteriolar wall in vivo using phosphorescence quenching microscopy to measure the partial pressure of oxygen in two areas almost simultaneously. The K value of arteriolar wall (inner diameter, 63.5 ± 11.9 μm; wall thickness, 18.0 ± 1.2 μm) was found to be 6.0 ± 1.2 × 10(-11) (cm(2)/s)(ml O(2)·cm(-3) tissue·mmHg(-1)). The arteriolar wall O(2) consumption rate (M) was 1.5 ± 0.1 (ml O(2)·100 cm(-3) tissue·min(-1)), as calculated using Krogh's diffusion equation. These results suggest that the arteriolar wall consumes a considerable proportion of the O(2) that diffuses through it.
authors: Graduate School of Science and Technology, Keio University, Tokyo,           Japan.
authors: Nobuhiko
authors: N
authors: Sasaki
authors: Hirohisa
authors: H
authors: Horinouchi
authors: Akira
authors: A
authors: Ushiyama
authors: Haruyuki
authors: H
authors: Minamitani
mesh_terms: D000818:Animals; D001160:Arterioles / Q000502:physiology*; D001692:Biological Transport / Q000502:physiology; D001783:Blood Flow Velocity; D001790:Blood Physiological Phenomena; D002196:Capillaries / Q000502:physiology*; D002199:Capillary Permeability / Q000502:physiology*; D003911:Dextrans; D004058:Diffusion; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives; D005456:Fluorescent Dyes; D007700:Kinetics; D008163:Luminescent Measurements; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008853:Microscopy; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D010313:Partial Pressure; D038761:Photobleaching
chemical_list: D003911:Dextrans; D005456:Fluorescent Dyes; C015219:fluorescein isothiocyanate dextran; D016650:Fluorescein-5-isothiocyanate; D010100:Oxygen