Registration Dossier

Administrative data

Endpoint:
additional toxicological information
Adequacy of study:
other information
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: secondary reference

Data source

Reference
Reference Type:
publication
Title:
No information
Author:
Tomingas, R. et al.
Year:
1971
Bibliographic source:
Zbl. Bakt. Hyg., I. Abt. Orig. B 155, 148-158

Materials and methods

Type of study / information:
Cytotoxicity and elution of BP
Test guideline
Qualifier:
no guideline required
Principles of method if other than guideline:
The aim of the study was to learn whether the macrophages were able to elute BP from supporting materials. The CB and the furnace-dust were extracted with benzene, dried and then charged with BP. Macrophages were obtained from guinea pigs and cultured in a medium NCTC 109 with 10% guinea pig serum. Incubation was carried out in SOVIREL-bottles. Each bottle contained 8 millions of peritoneal respectively 5, 2 millions of alveolar macrophages. Macrophages were incubated with 4 ml of medium NCTC 109 in which the CB and dusts were suspended by means of supersonic. Incubation was performed at 37 degrees in the dark. One, three and 20 hours after exposition incubation was stopped by additon of ethanolic KOH. The solids were separated from medium and the rest was determined by means of fluorescence spectroscopy. For the estimation of the cytotoxicity, three criteria were used: staining of the cells with Erythrosin B, measurement of the LOH-activity in the supernatant and the determination of the lactate production.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Carbon blacks (CB) Printex U, Corax L, Flammruss 101, and Inaktioruss MT (Degussa, Frankfort) as well as hematite and a dust from a melting-furnace were used for the experiments.

Results and discussion

Applicant's summary and conclusion

Conclusions:
The results showed that alveolar as well as peritoneal macrophages were capable of eluting BP adsorbed on CB and dusts but the elution rate was different. The amounts eluted from CB with a particle size smaller than 10 nm and with a large surface were smaller than those of the coarse-grained blacks. Hematite behaved like a fine-grained CB. The lowest value was found with the melting furnace dust. Flammruss and furnace-dust proved to be distictly cytotoxic. A relation between cytoxicity and elution of BP was not evident.
Executive summary:

It could be shown that macrophages were able to take up free BP and to metabolize this polycyclic hydrocarbon. BP when inhaled into the lungs is readily adsorbed on particles. Therefore, it was of some interest to learn whether the macrophages were also able to elute BP from supporting materials. Carbon blacks (CB) Printex U, Corax L, Flammruss 101, and Inaktioruss MT (Degussa, Frankfort) as well as hematite and a dust from a melting-furnace were used for the experiments. The CB and the furnace-dust
were extracted with benzene, dried and then charged with BP.
Macrophages were obtained from guinea pigs and cultured in a medium NCTC 109 with 10% guinea pig serum. Incubation was carried out in SOVIREL-bottles. Each bottle contained 8 millions of peritoneal respectively 5, 2 millions of alveolar macrophages. Macrophages were incubated with 4 ml of medium NCTC 109 in which the CB and dusts were suspended by means of supersonic. Incubation was performed at 37 degrees in the dark. One, three and 20 hours after
exposition incubation was stopped by additon of ethanolic KOH. The solids were separated from medium and the rest was determined by means of fluorescence spectroscopy.

The results showed that alveolar as well as peritoneal macrophages were capable of eluting BP adsorbed on CB and dusts but the elution rate was different. The amounts eluted from CB with smallest particle sizes and  with largest surface were less than those of the coarse-grained blacks. Hematite behaved like a fine-grained CB. The lowest value was found with the melting furnace dust. Flammruss and furnace-dust proved to be distictly cytotoxic. A relation between cytoxicity and elution of BP was not evident.