ABSTRACT
Heavy ions are the positively charged nuclei of the atomic number greater than two in the universe, which mainly comes from the charged particles of the solar system outside. Heavy ions occupy only 1% in cosmic ray, but because they are is capable of forming the Bragg peak, resulting in huge energy deposition, they have much more severe biological effects on immune organ than electromagnetic radiation in the cosmic rays. This paper outlines the biological effects of heavy ions on several aspects of immune organs, immune cells and chromosomes, and provide a theoretical basis for the study of the impact of heavy ion radiation on the immune system.
ABSTRACT
Objective To investigate the effect of asarone on the zebrafish embryonic development and behavior. Methods The 3 hours post fertilization(hpf) zebrafish embryos were exposed to different concentrations(0, 25,50,100,200 and 400 μmol/L) of asarone solution. The asarone solution was replaced each 24 h. Microscope was used to observe embryos morphology at 24,48,72 and 96 hpf, respectively. Spontaneous movements at 24 hpf, heart rate at 48 hpf, hatch rate, deformity rate and mortality rate were evaluated.The sepn1 gene expression of zebrafish in 96 hpf was detected by RT-qPCR. With Noldus tracking system the behaviors of zebrafish larvae exposed to asarone were recorded. Results After zebrafish embryos were exposed to the different concentrations of asarone, their spontaneous movements were decreased. Compared with the control group, the 100,200 and 400 μmol/L groups were significantly decreased (P<0.01). There was a significant difference(P<0.01) in 48 hpf heart rate between all asarone groups and control group. Spine curvature, pericardial edema, yolk sac edema and other deformity were observed at 72 hpf and 96 hpf. Compared with the control group, the 100, 200 and 400 μmol/L groups showed significanly decreased hatch rate(P<0.01). There was a significant difference (P<0.05) in mortality rate between the 400 μmol/L group and control group. With concentrations of asarone increasing, the speed and distance of movement of 200 and 400 μmol/L group were significantly reduced compared to the control group(P<0.05). There was a significant difference between the 200,400 μmol/L groups and the control group in activity(P< 0.01).At 96 hpf, the expression of sepn1 gene in arone groups were decreased compared to control group, especially the 100 μmol/L group(P<0.05), and the 200 and 400 μmol/L groups(P<0.01). Conclusion Asarone had teratogenic effect on zebrafish embryos and larvae ,and inhibitory effect on larvae behavior .We should be careful to use asarone in infant medication.