Figure 3. Oxygen content in arterioles and venules as a function of vessel diameter.

(a, b) Intravascular PO₂ and SO₂, respectively, as a function of arteriolar and venular diameters during normocapnia (solid symbols) and hypercapnia (empty symbols). Inverted triangle symbols represent mean values in precapillary arterioles. All mean PO₂ and SO₂ during hypercapnia experiments are statistically larger than mean PO₂ and SO₂ during normocapnia (Student t-test, P < 0.04, pairwise comparison for diameters < 25 μm and between combined measurements for diameters > 25 μm). Data are expressed as mean ± s.e.m. and were estimated averaging over all vessels over all animals. There were n = 3 mice for each group.