Ivannik B P, Golubeva R V, Riabchenko N I
Biokhimiia. 1977 Jun;42(6):994-1000.
Rat liver thymocytes were incubated in vitro with prednisolon, and molecular weight of single-stranded DNA was estimated in alkaline lysates of nuclei by viscosity methods. The number of single-stranded breaks was estimated, which originate in DNA after 3 hours of incubation with prednisolon at a concentration of 3-10(-9) M--3-10(-4) M. Maximal hormone effect was produced within 30 min., and it remained constant for the rest 3 hours of the incubation. Cycloheximide prevented hormone-induced DNA depolymerization, and actinomycin D only slightly inhibited the formation of single-stranded DNA breaks, originated after 30 min. incubation of thymocytes with prednisolon, were repaired after their washing and reincubation in the fresh medium for 1 hour at 37 degrees C. The washing of thymocytes and their reincubation for 3 hours resulted in the decrease of the molecular weight of single-stranded DNA. Possible mechanism of the formation of single-stranded DNA breaks in prednisolon-induced thymocytes is discussed.
将大鼠肝脏胸腺细胞与泼尼松龙在体外进行孵育，通过粘度法在细胞核的碱性裂解物中估计单链DNA的分子量。估计了单链断裂的数量，这些断裂是在胸腺细胞与浓度为3×10⁻⁹ M - 3×10⁻⁴ M的泼尼松龙孵育3小时后在DNA中产生的。最大激素效应在30分钟内产生，并在孵育的其余3小时内保持恒定。环己酰亚胺可防止激素诱导的DNA解聚，放线菌素D仅轻微抑制单链DNA断裂的形成，胸腺细胞与泼尼松龙孵育30分钟后产生的单链DNA断裂，在洗涤后于37℃在新鲜培养基中再孵育1小时可被修复。胸腺细胞的洗涤及其再孵育3小时导致单链DNA分子量降低。讨论了泼尼松龙诱导的胸腺细胞中单链DNA断裂形成的可能机制。
