DNA Synthesis in the Rat Lens Epithelium After Roentgen Irradiation
The effects of x irradiation on DNA synthesis and mitotic activity were studied in whole flat mounts of the rat lens epithelium by means of autoradiography after labeling with plete inhibition of mitosis from 2 to 24 hr after irradiation. During this interval the number of cells incorporating thymidine-H2 decreased gradually to 40% of the control value at 8 hr, and at 24 hr there was almost complete absence of labeled cells in the irradiated eye. Both mitotic activity and thymidine-H3 uptake resumed after 24 hr and increased steadily until normal values were reached st run. Concent 5 days after irradiation. Subsequently, the number of mitoses and labeled cells was consistently greater in the irradiated epithelium than in the control. The observations indicate that a dose of 1000-r x rays, in addition to blocking mitosis, temporarily depresses DNA snythesis in the lens epithelial cells. The effect on DNA synthesis is independent of the mitotic inhibition and appears to be due to a presynthetic block, which prevents new cells from entering the S period, and to a block of synthesis in some of the cells in the S period at the time of irradiation.
- Research Organization:
- National Inst. of Neurological Diseases and Blindness, Bethesda, Md.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-17-021485
- OSTI ID:
- 4715041
- Journal Information:
- Archives of Ophthalmology (Chicago), Journal Name: Archives of Ophthalmology (Chicago) Journal Issue: 6 Vol. 68; ISSN 0003-9950
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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