COMPARISON OF MOUSE AND RABBIT LUNG DAMAGE EXPOSURE TO 30 KHZ ULTRASOUND

Twenty-four mice and sixteen rabbits were evaluated at one exposure du ration (10 min) and at three exposure acoustic pressure levels (0, 100 and 145 kPa) at an ultrasonic frequency of 30 kHz, continuous wave fo r the purpose of testing whether there was a species difference in the degree of sensitivity to ultrasound-induced lung damage. This study w as undertaken because it was hypothesized that the mouse may not be an acceptable or suitable animal model for studies that examine the effe cts of ultrasound on lung tissue for purposes of extrapolating or esti mating the degree of potential damage in other species. The rabbit was selected for comparison to the mouse because the rabbit exhibited suf ficient physiological and morphological differences from those of the mouse to test this hypothesis. Using exactly the same exposure conditi ons and lung assessment criteria, it appeared that the mouse lung was more sensitive to ultrasound-induced damage than that of the rabbit by a factor of between 2.8 and 3.6. Lung lesions in mice and rabbits wer e similar in character, but were much more severe and extensive in mic e. Lesions in both species consisted of intraalveolar hemorrhage that appeared as dark red to red-black areas that were visible on the pleur al surfaces and that extend within the lung parenchyma.