Effect of Hypokinesia on Calcium Loss in Calcium-supplemented and -unsupplemented Rats

• Published in: Archives of medical research Vol. 39; no. 5; pp. 496 - 502
• Main Authors: Zorbas, Yan G, Kakuris, Kostas K, Deogenov, Viktor A, Neophitos, Eugenios A
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2008
• Subjects: Animals; ATP deficiency; Calcium - deficiency; Calcium - metabolism; Calcium - pharmacology; Calcium content; Calcium deposition; Cell injury; Dietary Supplements; Feces; Hypokinesia - metabolism; Internal Medicine; Lifestyle factors; Male; Nutrition; Physical inactivity; Rats; Rats, Wistar; Cell injury; Nutrition; Lifestyle factors; Calcium content; ATP deficiency; Calcium deposition; Physical inactivity
• ISSN: 0188-4409; 1873-5487
• DOI: 10.1016/j.arcmed.2008.04.001

Background We undertook this study to determine total calcium (Ca2+ ) loss in Ca2+ -deficient tissue and tissue Ca2+ loss with and without Ca2+ supplementation during hypokinesia (HK; diminished movement). Methods Studies were conducted on 240 male Wistar rats during a pre-experimental period of 9 days and an experimental period of 98 days. 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). Calcium supplementation of 2.6 mmol was given to animals in the SVCR and SHKR groups. Results Gastrocnemius muscle and right femur bone Ca2+ level reduced ( p <0.05) and plasma Ca2+ level, and urine and fecal Ca2+ loss increased ( p <0.05) in the SHKR and UHKR groups compared to their pre-experimental values and the values in their respective vivarium control groups (SVCR and UVCR). Muscle and bone Ca2+ content decreased more ( p <0.05), while plasma Ca2+ level, and urine and fecal Ca2+ loss increased more ( p <0.05) in the SHKR group than in the UHKR group. Conclusions Tissue Ca2+ deficiency during HK is more evident with than without Ca2+ supplementation and Ca2+ loss was exacerbated with higher than lower tissue Ca2+ deficiency. This shows that tissue Ca2+ deficiency does not result from the lower Ca2+ content in the food consumed and the total bodily Ca2+ loss is not caused by the higher tissue Ca2+ content but due to the impossibility of the body to use Ca2+ during prolonged HK.