Objective To explore the effects of sleep-wake rhythm intervention on blood cells in mice with aplastic anemia and its possible mechanisms of action by observing the changes in peripheral blood cell count and plasma circadian rhythm regulatory factors (MT, NE) in mice with aplastic anemia whose sleep-wake rhythm has been intervened. Methods Male C57BL/6 mice were randomly divided into the experimental groups [sleep-wake rhythm intervention groups (sleep intervention group, wakefulness intervention group, sleep-wake intervention group) and sleep-wake non-intervention group] and normal control group. In the experimental groups, we established the models of aplastic anemia in mice, while the mice in the normal control group did not undergo the model induction. The sleep-wake rhythm was maintained normally in the sleep-wake rhythm non-intervention group and the normal control group. The mice in the wakefulness intervention group and sleep intervention group received 24-hour light exposure and 24-hour sleep intervention, respectively. In the sleep-wake intervention group, sleep and wakefulness patterns were reversed for the first 3 days and the opposite in the following 3 days. Each group underwent a 9-day intervention period. Peripheral blood cell counts were measured in all groups on the day before intervention and on the 6th day after intervention. ELISA was used to measure the levels of MT, NE, OX, and PGE2 in the plasma and bone marrow of mice in the experimental and control groups before intervention. Plasma MT and NE levels were measured in each group on the day before intervention and on the 3rd, 6th, and 9th days after intervention. Results ① Comparison of blood cell counts before and after intervention in each group: Prior to intervention, compared with the normal control group, the experimental group had lower WBC, RBC, PLT counts, and HGB levels (all P<0. 01). On the 6th day of sleep-wake rhythm intervention, compared with the normal control group, the sleep-wake rhythm non-intervention group and sleep intervention group had lower WBC, RBC, and HGB levels (all P< 0. 01). The wakefulness intervention group and sleep-wake intervention group had lower WBC and HGB levels, but higher PLT levels in comparison with those of the sleep-wake rhythm non-intervention group (all P<0. 01). Compared with the sleep-wake rhythm non-intervention group, the wakefulness intervention group and sleep-wake intervention group had higher RBC and HGB levels (all P<0. 01). Compared with the sleep intervention group, the wakefulness intervention group and sleep-wake intervention group had higher PLT levels (all P<0. 05). ② Comparison of plasma MT and NE levels before and after intervention in each group: On the 3rd day of intervention, compared with the normal control group, the sleepwake rhythm non-intervention group and wakefulness intervention group had higher plasma MT levels (all P<0. 01). Com‐ pared with the sleep-wake rhythm non-intervention group, the wakefulness intervention group had higher plasma MT level (P<0. 01), while the sleep-wake intervention group had lower plasma MT level (P<0. 05). Compared with the sleep intervention group, both the wakefulness intervention group and sleep-wake intervention group had higher plasma MT levels (both P<0. 05). On the 6th day of intervention, there were no statistically significant differences in plasma MT levels among the groups, but a pattern emerged with the sleep-wake intervention group > sleep-wake rhythm non-intervention group > normal control group. On the 3rd day of intervention, compared with the normal control group, the sleep-wake intervention group had higher plasma NE level (P<0. 05). Compared with the sleep-wake rhythm non-intervention group, sleep intervention group, and wakefulness intervention group, the sleep-wake intervention group had higher plasma NE levels (all P<0. 05). On the 6th day of intervention, compared with the normal control group, the wakefulness intervention group had higher plasma NE level (P<0. 05), while the sleep-wake intervention group had lower plasma NE level (P< 0. 05). On the 9th day of intervention, compared with the normal control group and sleep intervention group, the sleepwake intervention group had higher NE level (both P<0. 05). Conclusions In mice with aplastic anemia whose sleepwake rhythm is intervened, there is an increase in peripheral blood cell count, as well as elevated levels of plasma MT and NE, indicating intervention in both sleep and wakefulness rhythms. Disrupted sleep-wake rhythm intervention may contribute to the elevation of blood cell count in mice with aplastic anemia by regulating MT and NE levels. [ABSTRACT FROM AUTHOR]