ISSN:
1615-6102
Keywords:
Hexavalent chromium
;
Cytotoxicity
;
Euglena gracilis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Synchronous cultures ofEuglena gracilis Klebs were grown axenically in continuous light for six days in the presence or absence of 1.5, 3.0, 4.5, 7.5, 9.0 μg/ml of Cr6+ supplied as K2Cr2O7. In the presence of chromium, cell proliferation was drastically inhibited and many giant organisms containing multiple nuclei frequently appeared. Chlorophyll content and photosynthetic activity diminished greatly. Accordingly, plastids, which increased abnormally in number in giant cells, showed a weak fluorescence and a reduced internal organization. Mitochondria were generally enlarged and variously branched while respiration rate fell. Nuclei were very large and frequently exhibited the ultrastructural characteristics of those in G2 phase of the cell cycle. The cell and nuclear membranes became more permeable to vital stains. In the giant cells the cytoplasm was frequently filled with an extraordinary accumulation of paramylum grains or almost totally replaced by enormous vacuoles. The observed alterations may be related to the formation of Cr-complexes with a variety of biological ligands, primarily nucleic acids, proteins and free SH groups.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01279866
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