Radiosensitivity of synchronized Tetrahymena pyriformis W. cells
Srinivas, H.; Vakil, U.K.; Sreenivasan, A.
Indian Journal of Biochemistry and Biophysics 11(4): 287-291
1974
ISSN/ISBN: 0301-1208 PMID: 4219848 Document Number: 76657
T. pyriformis can be a convenient test organism for preliminary assessment of quality in irradiated foods. Synchronous cell division was induced in T. pyriformis by cyclic heat treatments at 34.degree. and 25.degree. C for 30 min each time. About 90% of the cells underwent cytoplasmic fission after 95 min following 6 heat treatments. Retardation of cell growth during heat treatment was reflected in decreased [14C]leucine incorporation into newly synthesized proteins. The LD50 of the synchronously growing cells was 250 krad; radioresistance was increased by intermittent dosing. Mucopolysaccharide content and cell permeability were not affected in cells by gamma ray exposure. The organism had high catalase activity, which remained unchanged after irradiation, and its high radioresistance may be attributed to its structural integrity and high catalase activity.