Corynebacterium parvum injected intraperitoneally into C57BL mice induced a progression of hemopoietic CFU-S of C57BL mice from the resting state immediately after, and in the early period (approximately 8 h) after stimulation. Dose-response survival curves of the stimulated endogenous spleen CFU-S after the C. parvum injection revealed changing slopes or D0 of dose-response survival curves indicative of changing sensitivity states. Shortly after stimulation, the cells were sensitive to high specific-activity tritiated thymidine (HSATT) or hydroxyurea (HU), indicating they were in the DNA-S phase. This commenced shortly after the C. parvum injection. Beginning at about 6 h, sensitivity to HSATT disappeared and there was an increase in radiosensitivity. Sensitivity to vinblastine (VLB) also became evident at 7 h. This was consistent with beginning mitosis and mitotic cell sensitivity to VLB. A dose-response survival curve for the G2 phase CFU-S was determined using both HSATT and VLB to eliminate the DNA-S phase and mitotic cells. The radiosensitivities of the resting G1, S, and G1-S phase cells were determined by D0 to be 80, 105 and 85 rad, respectively, measured in vivo. G2 sensitivity using a combined HSATT and VLB method showed a complex, bending dose-response curve with a terminal D0 of 58 rad. CFU-S progression was blocked by the anti-histamine H2 receptor agent, metiamide.

中文翻译：

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小棒杆菌刺激的CFU-S放射敏感性的早期变化。

腹膜内注射到C57BL小鼠的小棒状杆菌诱导C57BL小鼠的造血CFU-S从刺激后立即以及在刺激后的早期（约8小时）开始从静止状态发展。微小隐孢子虫注射后受刺激的内源性脾脏CFU-S的剂量反应生存曲线显示出变化的斜率或剂量反应生存曲线的D0，表明敏感性状态发生了变化。刺激后不久，细胞对高比活性tri标记的胸苷（HSATT）或羟基脲（HU）敏感，表明它们处于DNA-S期。这是在小隐孢子虫注射后不久开始的。从大约6小时开始，对HSATT的敏感性消失，放射敏感性增加。对长春碱（VLB）的敏感性在7 h时也变得明显。这与开始的有丝分裂和有丝分裂细胞对VLB的敏感性一致。使用HSATT和VLB消除DNA-S期和有丝分裂细胞，确定G2期CFU-S的剂量反应生存曲线。静置的G1，S和G1-S期细胞的放射敏感性通过D0测定，分别在体内测量为80、105和85 rad。使用HSATT和VLB组合方法测得的G2灵敏度显示出复杂的弯曲剂量反应曲线，末端D0为58 rad。CFU-S进程被抗组胺H2受体药物甲酰胺阻断。通过D0确定在体内和体外，G1和G1-S期细胞分别为80、105和85rad。使用HSATT和VLB组合方法测得的G2灵敏度显示出复杂的弯曲剂量反应曲线，末端D0为58 rad。CFU-S进程被抗组胺H2受体药物甲酰胺阻断。通过D0在体内测定的G1和G1-S期细胞分别为80、105和85rad。使用HSATT和VLB组合方法测得的G2灵敏度显示出复杂的弯曲剂量反应曲线，末端D0为58 rad。CFU-S进程被抗组胺H2受体药物甲酰胺阻断。