Investigation of the Effects of Crystalline and Amorphous Silicic Acid Cultures on Lung Tissue

Abstract

The aim of the work was to determine the primary effect of crystalline and amorphous silica on lung tissue. For this purpose the method of tissue cultivation in “roller tubes”, modified according to Hintzsche, was employed. Crystalline silica and artificially prepared amorphous silicic acid were applied in four ways: (1) in solid medium; (2) in the liquid medium of rotating test tubes; (3) intrapulmonary; (4) in the solid medium of cultures according to Maximow. Normal lung tissue in the control series exhibited a development different from that of lungs incubated with the two kinds of SiO 2 . The difference was mainly in the character of histiotypical growth: both kinds of SiO 2 caused a gradual predomination of fibroblasts over epithelial elements. Atypical forms of fibroblast appeared mostly after intrapulmonar application of SiO 2 ; the fibroblasts had long fibrous pseudopods and they were often polynuclear. The prevailing part of the changes occurred at the beginning of the third three-day cultivation period. Cytological changes in fibroblasts occurred only when dust particles were in very close contact with cultivated tissue. Stimulation of growth activity of lung tissue was found only after the incubation of embryonic extract with amorphous SiO 2 . The level of SiO 2 in the liquid medium could not have been the cause of the alterations since for the most marked changes in histiotypical growth there were significantly lower values of SiO 2 than in experiments where alterations of growth were not proven. The experiments allow us to conclude that amorphous SiO 2 and crystalline silica possess certain common features of biological action; both interfere with the histiotypical growth of lung explantate, and may also influence the morphological character of fibroblasts.