(GLUCURONIC ACID EXCRETION IN URINE OF RABBITS BY EXPOSURE TO TOLUENE, XYLENE AND CARBON DISULFIDE.)

Abstract

Free-glucuronic acid and glucuronides excretion seem to be necessary to discuss toxicity and detoxition mechanism of various chemical substances in animal body. Present report was made with rabbits exposed to toluene, xylene and carbon disulfide in relatively low concentratons. Namely, the concentrations of these organic solvents were 211±19.3ppm in toluene, 209±28.5ppm in xylene and 108±17.5ppm in carbon disulfide respectively. Exposure chambers were designed for dynamic exposure. The time of exposure was 6 hours in all cases of these experiments.Analyses of urinary free-glucuronic acid and ether glucuronide were made by the naphtoresorcin picrate methods. Both wrs corrected by the concentration of urinary creatinine. Therefore, the value of glucuronic acid excretion in urine was expressed as G/C and OG/C ratio. The following results were obtained.1) The immediate decrease of G/C ratio in urine was observed after exposure of toluene. The reelevation to pre-experimental level after a cessation of the exposure would be comparatively slow. These responses mentioned above were shown more markedly in summer than that in winter. Also the response of OG/C ratio in urine resembled the change of G/C ratio exclusively.2) In the case of xylene exposure, the range of increase as to glucuronic acid excretion was from 117% to 129% in G/C ratio and from 121% to 142% in OG/C ratio. Two days after the exposure no increase of glucuronic acid in urine was observed. Metabolites of xylene in animal body would be apparently conjugated with glucronic acid and then eliminated into the urine shortly.3) Transient decreases of G/C and OG/C ratio were shown after exposure of carbon disulfide as well as that in the case of toluene inhalation. However, they were slight as compared with the decrease of G/C ratio by exposure to carbon disulfide in higher concentration.