RESUMO
@#Abstract: Objective To explore the effects of continuous light and benzene exposure on peripheral blood erythrocyte - Methods parameters and expression of miR 144/451 in the bone marrow of mice. This was a 2×2 factorial design. Photoperiod ， ， factor was set as normal and continuous light levels and mice were treated for 12 hours/12 hours light/dark or 24 hours light - respectively. The benzene exposure factor was set as non exposure and exposure levels. Mice were exposed to benzene by static 3 ， inhalation with a mass concentration of 0.0 and 32.5 mg/m for three hours per day five days per week for a total of four weeks. ， ， Specific pathogen free male C57BL/6 J mice were randomly divided into negative control group simple continuous light group - - ， ， simple benzene exposure group and combined exposure group with 12 mice per group. After benzene exposure peripheral ， blood was collected for the detection of erythrocyte parameters in four periods. After the mice were sacrificed the expression of - - - - miR 451a and miR 144 5p was detected by real time fluorescence quantitative polymerase chain reaction in bone marrow Results （ ）， ， tissues. The hematocrit volume HCT mean corpuscular volume mean corpuscular hemoglobin concentration （ ） - MCHC and mean corpuscular hemoglobin in peripheral blood and the relative expression of miR 451a in bone marrow tissue （ P< ） ， were statistically significant only in mice with benzene exposure all 0.05 . Among them the MCHC of benzene exposed （P< ）， （ P< ） - mice increased 0.05 but the other four indexes decreased all 0.05 compared with non benzene exposed mice. In thenegative control group the change of red blood cells count hemoglobin level and HCT in peripheral blood were rhythmical all P < ） ， （ P > ） rhythmical 0.05 . However the indexes above were out of rhythm all rhythmical 0.05 in the simple continuous light group and the - （ P > combined exposure group. The change of hemoglobin level and HCT of peripheral blood were also out of rhythm all rhythmical ） - - 0.05 in the simple benzene exposure group. The relative expression of miR 451a in bone marrow tissues of negative control （ P < ）， - group and simple continuous light group was rhythmical all rhythmical 0.05 while the relative expression of miR 451a in simple - - （ P > ）Conclusion benzene exposure group and combined exposure group was out of rhythm all rhythmical 0.05 . Benzene exposure ， induced changes in erythrocyte parameters of mice are independent effect and its mechanism may be related to the rhythmic - ， expression disorder of miR 451a in bone marrow tissues. Continuous light exposure benzene exposure and their interactions can ， interfere with the circadian rhythm of erythrocyte parameters such as red blood cell count hemoglobin and HCT to some extent.