Drewinko B, Yang L Y
Invest New Drugs. 1983;1(3):197-202. doi: 10.1007/BF00208890.
The survival response of human colorectal carcinoma cells treated in vitro for 1 h with PCNU was characterized by a threshold exponential curve, Dq = 8 micrograms/ml (1 h) and Do = 22 micrograms/ml (1 h). Continuous treatment induced decreasing degrees of cell kill although PCNU was biologically stable in solution for at least 24 h. Cells treated with PCNU were unable to recover from potentially lethal damage but were quite capable of repairing PCNU-induced sublethal damage. Thus, PCNU with different alkylating and carbamoylating than other nitrosourea congeners had similar cytotoxic and repair inhibition capacities. Any therapeutic gain in the clinical use of PCNU must derive only from its lipophilic properties and not from its superior activity at the cellular level.
用PCNU体外处理人结肠癌细胞1小时后的存活反应以阈值指数曲线为特征，Dq = 8微克/毫升（1小时），Do = 22微克/毫升（1小时）。连续处理导致细胞杀伤程度降低，尽管PCNU在溶液中至少24小时内生物学性质稳定。用PCNU处理的细胞无法从潜在致死性损伤中恢复，但能够修复PCNU诱导的亚致死性损伤。因此，与其他亚硝基脲同系物相比，具有不同烷基化和氨甲酰化作用的PCNU具有相似的细胞毒性和修复抑制能力。PCNU临床应用中的任何治疗优势都必须仅源于其亲脂性，而不是其在细胞水平上的优越活性。
