Biomedical subjects

L Poellinger

Publications and source records attributed to L Poellinger.

93 records · Page 6Linked to original sources

PubMed1981

Effects of dioxane on RNA synthesis in the rat liver.

The effect of dioxane on transcription was investigated. On intravenous administration of the lower dose (10 mg/rat) both RNA polymerase A and B activities were initially depressed but recovered after 1 h. A secondary effect on RNA polymerase A was observed but the enzyme activity recovered at 24 h when it was about 35% above control values whereas RNA polymerase B activity had achieved control values. With a higher dose (100 mg/rat) the pattern was similar but the suppressive effects were more pronounced - RNA polymerase B activity never attained control values during the times studied whereas there was no increase in RNA polymerase A activity at 24 h.

Animals↗

PubMedDate not supplied

In vitro characterization of possible mechanisms underlying the selective in vivo accumulation of the PCB metabolite 4,4'-bis(methylsulphonyl)-2,2',5,5'-tetrachlorobiphenyl in the lung.

In vivo, the polychlorinated biphenyl (PCB) metabolite 4,4'-bis(methylsulphonyl)-2,2',5,5'- tetrachlorobiphenyl--(MeSO2)2TCB--selectively accumulates in the Clara cells of the bronchiolar epithelium and in the secretory contents of the bronchiolar lumen. In vitro characterization of the interaction of tritiated (MeSO2)2TCB with the lung suggests that this selective accumulation is due to the presence of a secreted ([3H]MeSO2)2TCB-binding protein in the respiratory tract of rats, mice and man. The protein appears to be an almost globular, low-molecular-weight acidic protein which binds ([3H]MeSO2)2TCB and certain other methylsulphonyl PCBs with high affinity. Because of the pathway outlined for accumulation, it is suggested that methylsulphonyl PCBs should be included in studies designed to elucidate the mechanism(s) of PCB-induced lung toxicity.

Animals↗

PubMedDate not supplied

Target cells for the polychlorinated biphenyl metabolite 4,4'-bis(methylsulfonyl)-2,2',5,5'-tetrachlorobiphenyl in lung and kidney.

Light microscope autoradiography was used to determine the cellular localization of the polychlorinated biphenyl metabolite 4,4'-bis([14C] methylsulfonyl)-2,2',5-5'-tetrachlorobiphenyl ([3H]TCB) in the lung and kidney of mice and rats. Microautoradiograms prepared from thaw-mounted freeze sections showed that the radioactivity in the lung was localized in the bronchiolar lumen and epithelium. In methacrylate sections (74-82% of radioactivity extracted), a highly selective labeling was registered in the apical cytoplasm of the Clara cells. A pronounced labeling was present also in certain goblet-like cells containing periodic acid-Schiff-positive granules. Gel permeation chromatography and density gradient centrifugation showed that 80-95% of the radioactivity in lung lavage fluid was bound to a specific protein previously characterized in rat and mouse lung cytosol. The protein appeared to be enriched in the lavage fluid, as compared to lung cytosol. These data suggest that [3H]TCB binds to a protein residing in the Clara and goblet-like cells and that the labeled TCB-protein complex is subsequently secreted into the airway lumen. As shown by microautoradiography, the radioactivity in the kidney was confined to a restricted portion of the nephron, predominantly to the apical region of the proximal tubular cells.

Animals↗