title: Comparison of labeled propanediol and urea as markers of lung vascular injury.
abstract: The purpose of these studies was a comparison of [14C]urea (U) and 1,3-[14C]propanediol (Pr) as measures of lung vascular permeability-surface area (PS) under base-line conditions and after lung injury caused by alloxan infusion in isolated perfused dog lungs. Indicator mixtures of 125I-albumin, 51Cr-red blood cells, 3HOH, and U or Pr were injected under base-line conditions, after 1.2 g of alloxan, and after an additional 0.8 g of alloxan. Indicator-dilution curves were analyzed from sampled outflow blood to provide PS, the square root of effective extravascular diffusivity multiplied by exchange surface area (D1/2S), and extravascular lung water (EVLW) from the tracer mean transit times (VW). Results show that alloxan increases PS and D1/2S for U, D1/2S for Pr, and VW and EVLW by desiccation. All indicator-dilution parameters correlate significantly with alloxan dose. Interpretation of Pr transport suggests that materials with lipid and hydrophilic pathways might be used in conjunction with U to minimize the effects of surface area changes and increase the sensitivity of these tracers to permeability alteration. In addition Pr may be a useful alternative to U as a marker of vascular damage.
mesh_terms: D000496:Alloxan; D000818:Animals; D001693:Biological Transport, Active; D002199:Capillary Permeability; D004285:Dogs; D066298:In Vitro Techniques; D008168:Lung / Q000098:blood supply / Q000378:metabolism; D055370:Lung Injury; D010477:Perfusion; D011409:Propylene Glycols / Q000378:metabolism*; D011652:Pulmonary Circulation; D011653:Pulmonary Diffusing Capacity; D014508:Urea / Q000378:metabolism*
chemical_list: D011409:Propylene Glycols; C041787:1,3-propanediol; D000496:Alloxan; D014508:Urea