Early biological effects of whole body irradiation on rat lungs.

The influence of whole-body irradiation (WBI) with 4, 8 and 15 Gy ionizing radiation upon some biochemical indices in the bronchoalveolar lavage fluid (BALF) of rat lungs was studied. It was established that lactate dehydrogenase (LDH), alkaline phosphatase, (APH) and acid phosphatase (AcPH) activities show a dose-dependent decrease on the day 1 and day 5 after the irradiation. A similar trend was observed in the total protein content on the day 1. Angiotensin converting enzyme (ACE) activity was increased on the day 1 in the groups irradiated with 8 Gy and 15 Gy in comparison with the controls (190,2% and 187,5%, respectively). It was concluded that WBI decreases LDH, APH and AcPH levels in the lung cells, which secrete them into bronchoalveolar spaces. An irradiation with 8 Gy and 15 Gy WBI provokes an early damage on cytoplasmic membranes of the endothelial cells in lung capillars. It was considered that the bronchoalveolar lavage can find a more wide application for evaluation of the biological effect of ionizing radiation in lungs.