title: Biological effects of tremolite.
abstract: Tremolite is an amphibole which has been implicated in a variety of disease patterns in different parts of the world. It occurs in a number of phases, which are chemically identical but have specific physical characteristics. In an attempt to clarify the epidemiological findings, tremolite fibres of 3 specific forms--A, B and C--were characterized and studied for biological activity by: (i) in vivo intrapleural injection of rats (2 separate experiments--1 with poor survival). (ii) in vitro enzyme release from mouse peritoneal macrophages (iii) in vitro giant-cell formation in A549 cultures (iv) in vitro cytotoxicity for V79-4 cells. Sample C, which contained more long thin fibres than A and B, was alone in producing mesotheliomas. C, but not A or B, induced LDH and B-glucuronidase enzyme release, and induced giant cells. A was not cytotoxic, B moderately cytotoxic and C as highly cytotoxic as UICC crocidolite. The in vivo studies were marred by being split between 2 experiments, of which the second had poor survival. We are aware of the weakness of our in vivo data, but as Tremolite C was being considered for commercial use on the European market we felt it timely to submit our findings for publication.
mesh_terms: D000818:Animals; D017636:Asbestos, Amphibole; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004391:Dust; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000209:etiology*; D008264:Macrophages / Q000201:enzymology; D008297:Male; D008654:Mesothelioma / Q000209:etiology*; D051379:Mice; D009152:Mutagenicity Tests; D009374:Neoplasms, Experimental / Q000209:etiology; D010316:Particle Size; D051381:Rats; D011919:Rats, Inbred Strains; D012824:Silicic Acid / Q000009:adverse effects*; D012822:Silicon Dioxide / Q000009:adverse effects*
chemical_list: D017636:Asbestos, Amphibole; D004391:Dust; D012824:Silicic Acid; C005846:tremolite; D012822:Silicon Dioxide