Short term disposition of soluble vs. insoluble forms of cadmium in rat lung after intratracheal administration: an autoradiographic assessment.

An autoradiographic study was undertaken to compare the initial distribution patterns of soluble and less soluble forms of cadmium in the rat lung after intratracheal (i.t.) instillation. Male Sprague--Dawley rats were divided into 2 groups, each group received either soluble or a less soluble cadmium (109Cd) i.t. in 0.1 ml buffered saline. At 5, 30 and 90 min post-instillation, rats were sacrificed and processed for autoradiography, and radioactivity estimation of lung sections. 109Cd was unevenly distributed in the lungs at 5 min for both forms of Cd. At 90 min post-instillation, 109Cd was almost evenly distributed in the lung instilled with the soluble form; in case of the less soluble form a spotty distribution of 109Cd in the bronchi was observed. 109Cd was mainly translocated to the liver and stomach, followed by the kidney and intestine. It is apparent that the initial translocation of instilled 109Cd from the lung is relatively slow in the case of less soluble form as compared with the soluble form.