Some parameters of heme and drug-metabolism were measured in sham and partially-hepatectomized rats following a single intraperitoneal injection of tin (II) tartrate (2 mg tin/100 g B. Wt.). One day after treatment, tin, in partially hepatectomized rats produced a depression of activities of delta-aminolevulinic acid synthetase and delta-aminolevulinic acid dehydratase, and induction of heme oxygenase. These changes were accompanied by the marked reduction in the levels of cytochrome P-450 and benzo (a) pyrene hydroxylase. Accumulation of tin measured by incorporation of 113tin was 23% less in liver of hepatectomized rats than sham-operated rats, however the accumulation of 113tin in microsomal fraction was much higher in partially hepatectomized rats.
Effects of dioctyltin oxide (DOTO) tricyclohexyltin hydroxide (TCHTOH) and tributyltin oxide (TBTO) were examined on some enzymic activities in liver and kidney and biogenic amines level in brain of rats at 24 hours after single subcutaneous administration (25 μmole/100 g B. Wt.). All the organotin compounds produced a significant increase in the activity of alkaline phosphatase and adenosin triphosphatase and decrease in monoamine oxidase in both liver and kidney. DOTO and TCHTOH were more effective in impairing the activity of succinate dehydro-genase in liver. Concentrations of γ-aminobutyric acid (GABA) and dopamine were found to be significantly decreased in brain however, acetylcholine concentration remained unaltered. These results suggest that organotin compounds DOTO and TCHTOH are more toxic to rats than TBTO.
The efficacy of 2, 3 dimercaptopropane 1, sulphonate (DMPS) to enhance urinary excretion of lead, reduce the concentration of Pb in blood, brain, kidneys and liver and restore Pb induced alterations in the activities of renal and blood enzymes and brain biogenic amines in rats with normal or experimentally damaged kidneys, was investigated. The acute renal damage was induced by uranyl acetate prior to treatment with DMPS. The chelating agent was effective in reducing body burden of Pb by enhancing its excretion and in restoring biological altera-tions, more markedly in animals with normal kidneys than in those with acutely damaged kidneys. However, the increased brain concentration of Pb and altered levels of brain catecholamines remained unaffected on treatment with DMPS.
The preventive effect of pretreatment with zinc (Zn) on cadmium (Cd) nephrotoxicity in rats was evaluated by the measurement of enzyme activity in urine. The enzymes examined were γ-glutamyltranspeptidase (γ-GTP, EC 184.108.40.206), glycylproline-diaminopeptidase (GP-DAP, EC 220.127.116.11), alkaline phosphatase (Al-P, EC 18.104.22.168) and leucine aminopeptidase (LAP, EC 22.214.171.124). Three groups of male Sprague-Dawley rats were used. The first group received a single subcutaneous injection of 5.0 mg/kg body weight (5 rats, Cd Group), the second received a dosage of 250 μmol Zn/kg 24 hours prior to the same dosage of Cd (5 rats, Zn-Cd Group) and the third received the same dosage of Zn (5 rats, Zn Group). On the 1st day after Cd injection, significant elevation of both γ-GTP and GP-DAP activities in urine were observed in Cd Group, while in Zn-Cd Group the two enzyme activities were not elevated significantly compared to the reference values. On the 2nd day, γ-GTP and GP-DAP activities of Cd Group were reduced comparing with the first increase and those of Zn-Cd Group showed first a significant increase. On the 3rd day and after, both enzyme activities were almost the same as the reference value. The increase of enzyme activities in urine was explained to be caused by the leakage from renal cells. In Zn Group, both enzyme activities were observed little change in the course of the experiment. The excretion pattern of Al-P and LAP into urine differed from those of γ-GTP and GP-DAP in all groups. No histopathological changes under optical microscopy were observed in the livers and the kidneys of all groups. From these results, it appears that Zn Pretreatment showed a preventive effect on Cd nephrotoxicity in terms of enzyme activities in urine before any histophthological changes were seen.
Determination of urinary hippuric acid and phenolic compounds of operators (n=33) working under relatively low concentration of toluene (average : 55 ppm) showed a good correlation between the hippuric acid and o-and p-cresol (r=0.58 and 0.72, respectively). p-Cresol was always detectable in the urine in contrast to o-and m-cresol, which were absent from the urine of 10% of the operators exposed to toluene. In rats, experimentally injected with [methyl-14C] toluene was metabolized into o-, p-and m-cresol. Furthermore, the level of urinary cresol was not affected by intake of soft drinks, foods or medicaments, which had pronounced effects on the urinary hippuric acid level. The measurement of o-and p-cresol as well as hippuric acid concentration in the urine was therefore thought to be a useful index for the occupational health surveillance of toluene exposed workers.
In 108 workers occupationally exposed to benzene, toluene and xylene the numbers of lymphocytes containing intact lysosomes having cytochemically determined activity of N-acetyl-beta-D-glucosaminidase (NAG) were calculated in the peripheral blood. The benzene, toluene and xylene concentration in the air of at work places were 0-370, 0-580 and 0-506 mg/cu. m, respectively. The phenol concentration in the urine of workers collected between the 6th and the 8th hour of daily work was 16.2 mg/l (SD =9.6). It was stated that one of cytochemical indices of exposure to above compounds was in lowering of numbers of lymphocytes having intact NAG-positive lysosomes. Above phenomenon was noted in subjects having service time longer than 55 months and it was not accompanied by clinical signs of diminished immunity or disturbances in immune skin reactions against such antigens as tuberculin or distreptase.
It is important to determine spectra of optical radiation from light sources at workplaces, because they usually emit lights of various wavelengths simultaneously and these differ in their degree of harmfulness. Spectra of optical radiation (wavelength range: 200-1, 000 nm) from the arc of various arc welding processes were measured, using a multichannel detector system. For each process, a stable relative spectrum (a shape of the spectrum) was obtained in spite of the fluctuations in intensity. The relative spectrum is determined mainly by the welding material, such as steel or aluminum, regardless of the other parameters. Especially, it is independent of the diameter of wire, arc current and arc voltage, which have an influence only on the absolute intensity of the radiation.