texas-red and Reperfusion-Injury

Fluorescently labeled albumin is used frequently as a tracer when monitoring microvascular permeability. Several fluorescent dyes are available for labeling protein, including fluorescein isothiocyanate (FITC) and Texas Red (TR). Because differences in leakage of dye-labeled proteins have been reported, the objective of the present study was to compare the accumulation of these two tracers in interstitium and lymph after the inflammatory event of ischemia-reperfusion.. Anesthetized rats were injected intravenously with FITC-labeled albumin (FITC-alb) and TR-labeled albumin (TR-alb) before 30 minutes of mesenteric ischemia. Because the tracers leaked out of the microcirculation after reperfusion, accumulation in the surrounding buffer-superfused tissue, and in separate experiments, accumulation in lymph vessels, was defined as the ratio of tissue-to-plasma and lymph-to-plasma fluorescence.. Reperfusion induced a significant increase in tissue-to-plasma fluorescence of FITC-alb; however, no increase was observed for TR-alb. In contrast, lymph-to-plasma fluorescence of TR-alb tended to be greater than FITC-alb. Reperfusion-induced increases in tissue-to-plasma fluorescence of TR-alb occurred only when the superfusate was replaced with mineral oil, in which case tissue-to-plasma TR-alb fluorescence tended to be greater than FITC-alb.. Measurement of fluorescently labeled albumin leakage from mesenteric venules depends on the dye used to label the albumin and requires an assessment of losses from the extravascular measuring region.

Topics: Albumins; Animals; Biological Transport; Capillary Permeability; Emollients; Fluorescein-5-isothiocyanate; Fluorescent Dyes; Ischemia; Lymph; Male; Mesentery; Mineral Oil; Perfusion; Rats; Rats, Inbred F344; Reperfusion Injury; Xanthenes