Solute movement across the alveolar-capillary membrane after intratacheally administered bleomycin in rats

Abstract

The rate of absorption across the alveolar-capillary membrane of inhaled 99mTc-DTPA and the concentration of albumin in the bronchoalveolar lavage (BAL) fluid were characterized in a rat model of bleomycin-induced pulmonary fibrosis. Adult male Lewis rats were studied from 1 h to 120 days after a single intratracheal instillation of bleomycin (0.5 to 0.6 U/100 g body weight). The retention of 99mTc-DTPA in the lungs, expressed as a percentage of the baseline radioactivity was determined at 15 min (%R15) after delivery of the tracer. The %R15 was 83.7 ± 6.0 for normal untreated rats and 84.3 ± 3.7 for saline-treated animals. The rate of absorption of 99mTc-DTPA began to increase 24 h after bl..