Effect of talc injected intravenously in guinea pigs

The pulmonary angiothrombotic lesions in narcotic addicts attributed to the talc present in drug tablets were studied experimentally in guinea pigs following repeated intravenous administration of a suspension of talc dust (75 mg per animal). In early periods there was a moderate localization of talc particles in the alveolar capillaries of lung, liver and abdominal lymph nodes. The vascular injury in the pulmonary tissue was in the form of mild proliferation of the endothelial cells. In addition, many nodular collections comprising macrophages and lymphocytes developed around such vascular structures. At later periods (150 days) the only significant reaction obtained was moderate thickening of interalveolar septa and the lesions were in no way comparable to the human reports. The significance of these findings has been discussed.