Experimental and theoretical studies of oxygen gradients in rat pial microvessels.

ABSTRACT: Using modified oxygen needle microelectrodes and intravital videomicroscopy, measurements were made of tissue oxygen tension (PO(2)) profiles near cortical arterioles and transmural PO(2) gradients in the pial arterioles of the rat. Under control conditions, the transmural PO(2) gradient averaged 1.17+/-0.06 mm Hg/microm (mean+/-s.e., n=40). Local arteriolar dilation resulted in a marked decrease in the transmural PO(2) gradient to 0.68+/-0.04 mm Hg/microm (P<0.001, n=38). The major finding of this study is a dependence of the transmural PO(2) gradient on the vascular tone of the pial arterioles. Using a model of oxygen transport in an arteriole and experimental PO(2) profiles, values of radial perivascular and intravascular O(2) fluxes were estimated. Our theoretical estimates show that o

SUBMITTER: Sharan M 

PROVIDER: S-EPMC3529159 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature