Figure 1.
Hypomagnetic environment experimental device.
(A) Geomagnetic field shielding chamber; (B) The schematic diagram of tail suspension; (C) Rats tail suspension cage.
Figure 2.
Changes in bodyweight from the original weight of rats in different groups.
Rats in all 4 groups were weighed every 7d. C: Rats were raised in a wooden box with a normal GMF for 28 days; HLU: Rats were suspended, unloaded with −30° downward head tilting, and raised in a wooden box; HMF: Rats were raised normally in a GMF-shielded room; HMF+HLU: HLU rats were raised in a GMF-shielded room. **P<0.01 vs C, *P<0.05 vs. C, ##P<0.01 vs. HMF.
Figure 3.
The ultimate force (A), toughness factor (B), and elastic modulus (C) were obtained by analyzing the load–deformation curve. BL:The baseline group. Rats were executed to get basal data on day 0 of the experiment. C: Rats were raised in a wooden box with a normal GMF for 28 days; HLU: Rats were suspended, unloaded with −30° downward head tilting, and raised in a wooden box; HMF: Rats were raised normally in a GMF-shielded room; HMF+HLU: HLU rats were raised in a GMF-shielded room.**P<0.01,*P<0.05.
Figure 4.
Changes in femoral BMD and BMC measured by DEXA.
BL: The baseline group. Rats were executed to get basal data on day 0 of the experiment. C: Rats were raised in a wooden box with a normal GMF for 28 days; HLU: Rats were suspended, unloaded with −30° downward head tilting, and raised in a wooden box; HMF: Rats were raised normally in a GMF-shielded room; HMF+HLU: HLU rats were raised in a GMF-shielded room. BMD: bone mineral density; BMC: bone mineral content; **P<0.01.
Figure 5.
Effects of HMF and HMF+HLU on the femur trabecular bone.
ROI: A 2.019-mm-thick trabecular bone chip under the epiphyseal plate in the lower end of the femur was selected as the region of interest (ROI). BL: The baseline group. Rats were executed to get basal data on day 0 of the experiment. C: Rats were raised in a wooden box with a normal GMF for 28 days; HLU: Rats were suspended, unloaded with −30° downward head tilting, and raised in a wooden box; HMF: Rats were raised normally in a GMF-shielded room; HMF+HLU: HLU rats were raised in a GMF-shielded room. (A) Three-dimensional trabecular bone architecture of an ROI located under the epiphysis plate of the femur. (B) The degree of anisotropy is a measure of the extent of the orientation of the substructures in an ROI of trabecular bone, which represents the directivity and symmetry of the trabecular structure; a1/a3, a1/a2, and a2/a3 are the ratios of the long to the short diameters on 3 mutually perpendicular plane ellipses inside the ellipsoid. **P<0.01 vs. C, *P<0.05 vs. C, #P<0.05 vs. HLU, △△P<0.01 vs. BL, △P<0.05 vs. BL.
Table 1.
Microarchitectural quantitative analysis results of an ROI in the femur trabecular bone.
Table 2.
The axial values of microarchitectural quantitative analysis of an ROI in the femurtrabecular bone.
Table 3.
Microarchitectural quantitative analysis results of an ROI in the femur cortical bone.
Figure 6.
Effects of HMF and HMF+HLU on RANKL expression in femur.
C: Rats were raised in a wooden box with a normal GMF for 28 days; HLU: Rats were suspended, unloaded with −30° downward head tilting, and raised in a wooden box; HMF: Rats were raised normally in a GMF-shielded room; HMF+HLU: HLU rats were raised in a GMF-shielded room. (A) Immunohistochemical staining of RANKL expression in femur. Brown cells are RANKL expression positive cells. (400×); (B) Semi-quantitative data figure of RANKL expression. HSCORE 100∼400: positive expression.
Figure 7.
Effects of HMF and HMF+HLU on the concentrations of serum bALP, DPD and GCs.
BL: The baseline group. Rats were executed to get basal data on day 0 of the experiment. C: Rats were raised in a wooden box with a normal GMF for 28 days; HLU: Rats were suspended, unloaded with −30° downward head tilting, and raised in a wooden box; HMF: Rats were raised normally in a GMF-shielded room; HMF+HLU: HLU rats were raised in a GMF-shielded room. Serum concentrations of (A) bALP (µg⋅L−1), (B)DPD (nmol⋅L−1), and (C) GCs (ng⋅L−1). **P<0.01.
Figure 8.
Effects of HMF and HMF+HLU on the concentrations of serum trace elements.
BL: The baseline group. Rats were executed to get basal data on day 0 of the experiment. C: Rats were raised in a wooden box with a normal GMF for 28 days; HLU: Rats were suspended, unloaded with −30° downward head tilting, and raised in a wooden box; HMF: Rats were raised normally in a GMF-shielded room; HMF+HLU: HLU rats were raised in a GMF-shielded room. Serum concentrations (mg L−1) of (A) iron, (B) calcium, (C) copper, (D) magnesium, (E) manganese, and (F) zinc. *P<0.05, **P<0.01.