Formation of Pseudo-Asbestos Bodies on Sized Glass Fibres in the Hamster Lung

Sized glass fibres, 3 μm in diameter and with lengths ranging from 10 to 100 μm, were administered to hamsters by intratracheal instillation. Animals were killed serially and fibres extracted from their lungs by hypochlorite digestion. Determinations were made of fibre dimensions with the light microscope and whether they were uncoated, partially or fully coated. As shown in previous studies with rats, the longer fibres dissolved more rapidly than the short, but all fibres dissolved more rapidly in the hamster than in the rat lung. Partially coated fibres were detected after 1 month for the 60 and 100μm and after 2 months for the 10 and 30 μm. There were wide variations in the frequency of coated fibres in different animals killed at the same time, but it tended to increase up to 5 months and then to decline. It was clear that the coating of glass fibres did not prevent their dissolution.