Magnesium deposition and depletion in magnesium supplemented rats during and after hypokinesia and vivarium control

Hypokinesia (diminished movement) induces significant magnesium (Mg) changes; however, little is known about Mg deposition and Mg depletion during HK. Measuring the Mg level in some tissues during HK and post-HK and Mg supplement, we aimed to establish Mg deposition and Mg depletion during prolonged HK. Studies were done on 408, 13-wk-old male Wistar rats (370-390 g) for a 15-d pre-HK period, a 98-d HK period, and a 15-d post-HK period. Rats were equally divided into four groups: unsupplemented vivarium control rats (UVCR), unsupplemented hypokinetic rats (UHKR), supplemented vivarium control rats (SVCR), and supplemented hypokinetic rats (SHKR). Both UHKR and SHKR were kept in small individual cages. The SVCR and SHKR took 53 mg Mg/d. During the HK period, plasma, urinary, and fecal Mg levels increased significantly (p < or = 0.05), whereas during the post-HK period Mg deposition, muscle and bone Mg content decreased significantly (p < or = 0.05) in UHKR and SHKR when compared with their pre-HK values and their respective vivarium controls (UVCR and SVCR). During the initial days of the post-HK period, plasma, urinary, and fecal Mg levels decreased significantly (p < or = 0.05), whereas during the post-HK period Mg deposition, muscle and bone Mg content remained significantly (p < or = 0.05) depressed in UHKR and SHKR when compared with UVCR and SVCR, respectively. However, during the HK period and post-HK period Mg deposition, bone, muscle, plasma, urinary, and fecal Mg levels changed significantly (p < or = 0.05) more in SHKR than UHKR. By contrast, during the HK period and post-HK period. Mg deposition, muscle, bone, plasma, urinary, and fecal Mg values change insignificantly (p > 0.05) in UVCR and SVCR when compared with their pre-HK values. It was concluded that reduced muscle, bone, plasma, urinary, and fecal Mg during post-HK and Mg supplement may demonstrate Mg depletion, whereas higher Mg loss during HK despite reduced muscle and bone Mg and Mg depletion might demonstrate Mg deposition incapacity during HK.