[Method for the quantitative study of pulmonary surfactant in histological preparations]

A method for quantitation of pulmonary surfactant directly on histological preparations is proposed. The method is based on measurements of the intensity of fluorescence of the inner alveolar layer on cryostate sections stained with rhodamine 6G according to Hackney. The measurement is done with a microfluorimeter in microV, and is peculiar in that in each case a standard alveole with fluorescent inner layer of th surfactant and a small part of the surrounding tissue gets on the photocathode of the microfluorimeter. This is achieved by setting the microfluorimeter diaphragm on a certain value with control of the object examined on the planimetric ocular mesh. The results of application of the method in examinations of the lungs of fetuses, stillborns, newborns dying with pulmonary pathology as well as lungs of experimental rats have demonstrated a high positive correlation (+ 0.96) with measurements of the surface tension of endotracheobronchial washings obtained in examinations by the method of Clements.