title: [Changes of serum alkaline phosphatase and electrolytes during 21 d head down bed-rest].
abstract: Objective. To investigate the effect of simulated weightlessness on serum alkaline phosphatase (ALP), calcium, magnesium, chlorine and phosphorus. Method. 6 healthy males, aged 24.8 +/- 6.1, were exposed to -6 degrees HDT bed rest for 21 d. Activity of serum alkaline phosphatase, serum contents of calcium (Ca), magnesium (Mg), chlorine (Cl) and phosphorus (P) ions were assayed before HDT (d-3), on the 3rd, 10th and 21st day during HDT and after HDT (d+2). Ca was measured by methyl thymol blue method, P was determined with ultraviolet spectrophotography, determination of Mg and Cl were made with enzyme method, ALP was examined with 4-nitrobenzene phosphate method. Result. Serum Ca2+ levels were significantly higher at d10, d2l and d+2 than the value of d-3 (P<0.01). P3+ levels declined significantly on d2l as compared with d-3 (P<0.01). During the HDT and after HDT, Mg2+ declined to a level below that before HDT (P<0.05 or P<0.01). Cl- were significantly higher at d2l and d+2 than the value of d-3 (P<0.01). ALP level was higher on d2l than on d-3 (P<0.01). Conclusion. 21 d HDT induced increase of Ca, Cl, ALP, and decline of Mg and P. The changes may reflect the imbalance of metabolism.
authors.affiliation: Department of Aerospace Medicine, The Fourth Military Medical University, Xi'an, China.
authors.forename: Yong-jie
authors.initials: YJ
authors.lastname: Yao
authors.forename: Xi-qing
authors.initials: XQ
authors.lastname: Sun
authors.forename: Zhong-bo
authors.initials: ZB
authors.lastname: Wang
authors.forename: Shuang-bao
authors.initials: SB
authors.lastname: Zhao
authors.forename: Chang-bin
authors.initials: CB
authors.lastname: Yang
authors.forename: Xing-yu
authors.initials: XY
authors.lastname: Wu
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood / Q000378:metabolism*; D001510:Bed Rest; D001794:Blood Pressure / Q000502:physiology; D002118:Calcium / Q000097:blood / Q000378:metabolism; D002713:Chlorine / Q000097:blood / Q000378:metabolism; D018475:Head-Down Tilt; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008274:Magnesium / Q000097:blood / Q000378:metabolism; D008297:Male; D010758:Phosphorus / Q000097:blood / Q000378:metabolism; D014882:Water-Electrolyte Balance / Q000502:physiology*; D018474:Weightlessness Simulation
chemical_list: D010758:Phosphorus; D002713:Chlorine; D000469:Alkaline Phosphatase; D008274:Magnesium; D002118:Calcium