UNLABELLEDTo study the effect of a Chinese herbal prescription on external calcium deposition to weight-bearing bone in simulated weightlessness rats.

METHODTwenty-one male Wistar rats were divided into 3 groups: control group, tail suspension group, tail suspension with Chinese medicine group which takes a Chinese herbal prescription extract (containing Radix Rehmanniae Preparata, Radix Acanthopanacis Bidentatae, Radix Astragali, Radix Angelicae Sinensis, Concha Ostreae prepared by acetic acid) by intragastric administration. After 1 week adaption, there start off 3 weeks simulated weightlessness by tail suspension. At the eleventh day of simulated weightlessness, every rat was given one equal dose of 41Ca tracer by intragastric administration. Right femurs were separated as experiment over, and the ratio of 41Ca to 40Ca (41Ca/40Ca) was measured by accelerator mass spectrometry (AMS), while total femur calcium was measured by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Femur 41Ca deposition amount (DA) and femur 41Ca deposition ratio (DR) were calculated.

RESULTThe results showed that compared with control group, 41Ca/40Ca decreased significantly (P < 0.001) in tail suspension group, while in tail suspension with Chinese medicine group, it significantly increased (P < 0.05). DA and DR were both decreased significantly (P < 0.001) in tail suspension group, but no significant change in tail suspension with Chinese medicine group as compared with control group. Compared with tail suspension group, DA and DR increased significantly (P < 0.001) in tail suspension with Chinese medicine group.

CONCLUSIONSimulated weightlessness by tail suspension can cause decreased deposition of external calcium to weight-bearing bone, and the Chinese herbal prescription in this trial is effective to prevent the decrease. Moreover, multiple mechanisms may contribute to weightlessness induced osteoporosis, besides calcium deposition disturbance.