Mineral Content of Compact Bone in Rats after the Induction of Mild Hypothermia

Osteotropic macro- and microelements are important structural constituents of bone tissue and also components of macromolecules regulating bioorganic interactions. The disruption of their balance with age and under the influence of various unfavorable factors (in particular, an exposure to cold causing hypothermia) leads to structural changes in bones and development of such disease as osteoporosis. The objective of the research was to study the content of macro- and microelements in compact bone of rats of different ages after induced mild hypothermia. Materials and methods. The content of macroelements (Са, Р, Mg) and microelements (Zn, Fe, Cu) in the femoral diaphysis of 6- and 24-month-old rats after hypothermia due to exposure to cold (animals were placed in the temperature chamber at −20°С for 5 hours a day within a period of 5 days) was analyzed using the X-ray spectral fluorescent method. Results. In 6-month-old rats on the 14th day after mild hypothermia the content of phosphorus was 6.5 % higher and ratio Са/Р was 9.1 % lower than in control rats, and on the 28th day these indices and content of other mineral elements (Mg, Zn, Fe, Cu) did not differ from the control ones. In 24-month-old rats on the 14th day after hypothermia the content of phosphorus, magnesium and iron increased by 9.9%, 12%, and 36%, respectively and ratio Са/Р decreased by 8.4 % compared to the control group. On the 28th day the content of phosphorus was 11.3% higher and ratio Са/Р was 5.1% less than those in the control group. The index of magnesium content was high compared to the control (by 9.3 %) and did not differ from that on the 14th day after hyperthermia. The content of iron decreased by 68% compared to the 14th day and did not differ from that in the control group. The significant differences of the content of zinc and copper compared to the 14th day and control animals were not found. Conclusions. Hypothermia leads to the disbalance of macro- and microelements in compact bone, which is more expressed in 24-mounth-old rats