Errors in estimating lung liquid volume in fetal lambs when using radiolabeled serum albumin and blue dextran.
نویسندگان
چکیده
Fetal lung liquid volume is usually determined by using radio-iodinated serum albumin (RISA) or blue dextran (BD) as volume tracers. We tested the reliability of both tracers at 124 (G124) and 142 days of gestation (G142; term = G147) when the labels were employed simultaneously. We measured the proportion of label bound reversibly to the lung, or apparently lost from the lung compartment, by washing out the lung with saline and 5% albumin. At G124, volume estimates with the two labels were similar. At G142, the volume estimate with BD (36.3 +/- 8.7 ml/kg of body wt) was higher (P < 0. 05) than with RISA (22.3 +/- 3.5 ml/kg). This difference resulted from reversible binding of BD, because 5% albumin washout released 38.5 +/- 4.0% of the BD added at the start of the experiment but a lesser amount of RISA (9.8 +/- 0.7%; P < 0.05). At G142, when RISA was used alone, its reversible binding was 1.3 +/- 0.2%. Background absorbance increased during experiments, giving rise to an apparent increase in BD concentration. We conclude that RISA is an effective tracer for lung liquid volume determination in the fetal lamb, whereas our findings of substantial epithelial binding of BD and large changes in background absorbance demonstrate that, under the conditions of our experiments, BD is a poor tracer close to term.
منابع مشابه
Measuring lung liquid volume and secretion using radioiodinated serum albumin and blue dextran
Cassin, S., and A. M. Perks. Estimation of lung liquid production in fetal sheep with blue dye dextran and radioiodinated serum albumin. J Appl Physiol 92: 1531–1538, 2002; 10.1152/japplphysiol.00777.2001.—Lung liquid production and reabsorption rates and lung volumes were measured in 99 fetal sheep (119–148 days of gestation) by indicatordilution methods with the simultaneous use of blue dye d...
متن کاملMeasuring lung liquid volume and secretion using radioiodinated serum albumin and blue dextran.
متن کامل
Estimation of lung liquid production in fetal sheep with blue dye dextran and radioiodinated serum albumin.
Lung liquid production and reabsorption rates and lung volumes were measured in 99 fetal sheep (119-148 days of gestation) by indicator-dilution methods with the simultaneous use of blue dye dextran (BDD) and radioiodinated serum albumin (RISA). There were no significant differences between rates of lung liquid production or reabsorption by the two methods (n = 71 pairs; paired t-test; Wilcoxon...
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عنوان ژورنال:
- Journal of applied physiology
دوره 87 6 شماره
صفحات -
تاریخ انتشار 1999