Both erythrocyte and hepatic delta-aminolevulinic acid dehydratase (ALA-D) activities were simultaneously determined on mice administered 0.02% (w/v) lead in the drinking water. The ALA-D activity of erythrocytes was markedly depressed even at an early time of lead administration. On the other hand, the ALA-D activity of liver was not significantly inhibited until the termination of the lead administration. These data may suggest that the sensitivity of erythrocyte ALA-D to lead in vivo is dif-ferent from that of hepatic ALA-D, although the hepatic ALA-D activity had a significant correlation with the erythrocyte ALA-D activity (r=0.5532, p<0.001).
The effect of phenobarbital on the biliary excretion of metals in rats was com-pared among methyl mercury, inorganic mercury and cadmium compounds from which phenobarbital prevented animals. In rats given an i.v. administration of 1mg/kg Cd or Hg, large amounts of cadmium (15.1% of the dose) were found in the bile within 5 hr after the dose, but small amounts of mercury were excreted with bile (1.4 and 3.3% in inorganic mercury and methyl mercury groups, respectively). Phenobarbital significantly increased the biliary excretion of methyl mercury and cadmium (154 and 140% of controls, respectively), but not that of inorganic mercury. Concentrations of methyl mercury in the bile also increased in the treated rats, but those of cadmium did not change when compared with controls. Distribution of those metals in organs was not affected significantly by phenobarbital except for an increase in mercury content in blood obtained from rats given methyl mercury. These different effects of phenobarbital may reflect individual feature of in metabolism of three metals in the liver and those affinity to tissues.
Biochemical alterations in seminiferous tubules of rat, treated with manganese chloride (MnCl2.4H2O, 8 mg/kg) for 60 days were studied. The activity of succinic and lactic dehydrogenases and contents of glycogen, cholesterol and phospholipids were markedly reduced while no significant change was seen in the activity of acid and alkaline phosphatases and protein content in treated rats as compared to con-trols. These biochemical alterations in the sperm producing cells of the testis were observed apriori to morphological changes detectable under light microscope.
The degradation of malathion after 2 months, on feed sprayed with 0.08% and 0.16% of 50% malathion emulsifiable was 63 and 64% respectively. The half life was 30 days. Chicks fed with 32P malathion did not show any signs of toxicity. With lower dosage at 10 days, the concentration of 32P was highest in the kidney (10ppm), followed by liver (9ppm), blood (8ppm), heart and spleen (5ppm), lung (4ppm), intestine (3ppm), muscle (3ppm), and bone, brain and testes (2ppm). With the lapse of time 32P was slightly increased in different organs and at 30 days, it was maximum in liver followed by other organs. With higer dosage (800 ppm) the concentration of 32P was correspondingly higher in various organs under study. On stopping the treatment, 32P was abruptly decreased in all the organs and at 10 days (post-treatment), liver and kidney had less than 1ppm, whereas, no 32P was detected in other organs.
Zinc distribution in hepatic soluble fractions separated on Sephadex G-75, of rats treated with Ag+, Cu2+, Zn2+, Hg2+, Pb2+, Ni2+, In3+, Cr3+ or Sn4+ was studied and new zinc peaks were found in metal elution profile. Positions of these zinc peaks were correspondent with that of Cd2+-induced metallothionein. It is thought that these metal cations induced metallothionein or some proteins similar to metal-lothionein and that zinc linked to the proteins. Only silver and copper were in-corporated by the proteins and the other metals were not detected in the positions of the new zinc peaks.
Abstract-A new adsorbent for ammonia was developed by chemical treatments of active carbon. From adsorption isotherm observations at 25°C, it was shown that active carbon, which intrinsically little adsorbs ammonia, was improved to adsorb ammonia to various extents up to 8.40 mmol/g at Langmuir's monolayer coverage by oxidation with nitric acid solution and was further promoted by the im-pregnation of metals such as Ni, Co and Cu. The other adsorbents such as silica gel, alumina gel and aluminum oxide hydroxide were comparatively studied. Metal impregnation promoted the adsorptivities of these adsorbents for ammonia as well. Among the tested adsorbents, nickel impregnated oxidized active carbon showed the greatest adsorptivity of 9.4 mmol/g. The cupper impregnated oxidized active carbon was packed in gas mask can-isters and tested for air stream containing ammonia, proving that it serves for longer period than the adsorbents in current use.