The effect of different forms of food deprivation on calcium and magnesium concentrations in the serum, brain and femoral bone of female Wistar rats

Hypocalcaemia and hypomagnesaemia in patients with eating disorders are poorly identified, same as in animal models of these diseases. The purpose of the present study was to assess the concentration of calcium and magnesium in the serum, brain tissue and femoral bone of food restricted female Wistar rats. Material and Methods: 48 rats (8-weeks old, 199 ± 18 g) were divided into 6 groups (n = 8): the control group (C) were fed ad libitum, with measurements of daily intake, as a baseline for the amount of intake calculation for the other groups. The remaining five were testing groups: R50 – received half a portion of the diet eaten by C. The other groups were fed with a 100% of the diet eaten by C, but in a different model of food restriction: RI-IV – one-four day/s feeding, followed by one-four day/s starvation, throughout the eight weeks of the experiment. After wet mineralization of tissues, the calcium and magnesium concentrations were measured via the AAS method. Results: The calcium concentrations in serum and brain were unchanged, while the concentration of calcium in bone samples was significantly higher in food deprived rats compared to control groups rats. The influence of different models of food deprivation was observed in magnesium concentrations in the tissues studied. Generally, the levels of this mineral were significantly lower in all tissues in rats exposed to starvation than in control. Conclusions: The results of the current study suggest that although the amount of food intake was similar in all starvation models, food deprivation affects the management of calcium and magnesium in different ways. The competitiveness between these minerals, under food restriction, probably works to the benefit of calcium. This may lead to increased hypomagnesaemia and its subsequent implications.