Pattle's bubble-stability method in the rat

The following report deals with Pattle's alveolar bubble-stability method for surfactant studies in rats. There was no difference in stability ratio of bubbles obtained from separate lung lobes without gross pathological lesions. Bubble stability was not influenced by microscopic illumination (used only briefly for photographing) and by 1-day storage at plus 4degrees C. The stability ratio was significantly lower in distilled water in comparison with the value obtained in isotonic saline. If the time interval passing from squeezing of the bubbles to the time of the first measurement is strictly retained, the reliability of the method is satisfactory. The use of cummulative distribution curves of individual stability ratios' values and non-parametric testing of such results is recommended.