title: Escape from X-ray-induced arrest for lens cells stimulated from quiescence: time relationship to RNA, protein, and DNA synthesis.
abstract: Quiescent cells of the central zone region of the rat lens epithelium were stimulated to enter the proliferation cycle by wounding. RNA synthesis and a corresponding increase in poly(A)+/total RNA reached a peak by Hour 4. Cells progressed into the G1B compartment by Hour 10. A rise in protein synthesis began at Hour 8, and onset of DNA synthesis occurred by Hour 14. The timing of cell cycle progression that allowed escape from a dose of X irradiation that completely inhibited DNA synthesis was investigated. A growth-arrest point was identified at Hour 9 where 10 GY of X irradiation given before, but not after, completely inhibited earliest responding cells from entering DNA synthesis on schedule. Increased quantities of cells entered DNA synthesis on schedule as timing of the X irradiation was moved closer to the end of G1. Based on time relationships, the rise in protein synthesis is correlated with the "sufficient" event for the escape.
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000528:radiation effects*; D004247:DNA / Q000096:biosynthesis*; D005136:Eye Proteins / Q000096:biosynthesis*; D007908:Lens, Crystalline / Q000166:cytology* / Q000528:radiation effects; D008297:Male; D012313:RNA / Q000096:biosynthesis*; D051381:Rats; D013997:Time Factors
chemical_list: D005136:Eye Proteins; D012313:RNA; D004247:DNA