PRINCIPLES OF TOXICOLOGY - Biology East Borneo

406 PROPERTIES AND EFFECTS OF ORGANIC SOLVENTSFigure 16.36 Dimethyl sulfoxide.Signs and symptoms have pointed to the fact that dimethyl sulfoxide has systemic effects on the hepaticand renal system. It can inhibit enzyme reactions, but does not affect thyroid function. It has beensuggested that inhaled or otherwise administered DMSO is metabolically reduced to the dimethylsulfide and subsequently respired. DMSO in rats lowered the body temperature and enhanced thetaurine excretion and the toxic effects of aromatic hydrocarbons. It was found to influence thepreservation of leukemia cells and proved to be a potent inducer of erythroid differentiation in culturederythroleukemic cells. DMSO has teratogenic potential as well as the ability to increase activity andtumor-inducing effects of materials with carcinogenic potential.Carbon disulfide (see Figure 16.37) is a highly flammable, highly toxic solvent that historically hasbeen used in production of carbon tetrachloride, as well as the manufacture of rayon, cellulose fibers,rubber vulcanizers, and pesticides. Its previous use as a grain fumigant has been discontinued. Althoughthe pure substance is odorless, impurities may impart an objectionable sulfurous odor.The principal toxicological effect at high air concentrations is narcosis, perhaps accompanied byheadache, visual disturbances, respiratory disturbances, and gastrointestinal effects. Ingestion of aslittle as 15 mL may be fatal. Aside from the general neurological changes associated with acuteexposures, the greatest toxicological concern regarding carbon disulfide relates to the demonstratedability to induce peripheral polyneuropathy and psychoses in some chronically exposed individuals.The latter effects reportedly resolve following exposure cessation, but the characteristic neuropathiesmay persist. These include reflex decrements in the extremities, glove/stocking sensory loss, anddecreased nerve conduction velocity.Figure 16.37 Carbon disulfide.Figure 16.38 Thiazoles basic structure.