[Calcium and vitamin D metabolism and enzymes of xenobiotic metabolism during chronic action of mycotoxins].

Experimental rats received T-2 toxin (0.063 mg/kg), deoxynivalenol (1.6 mg/kg) and aflatoxin B1 (0.008 mg/kg) during 6 months. Moderately manifest changes were detected in metabolic enzyme activity of foreign substances in the liver and small intestine mucosa. All mycotoxins induced weak hypocalcemia, while ionized calcium concentration in the blood serum decreased only after T-2 toxin administration that was attended by an increase of PTH level. Alkaline phosphatase activity and calcium transport in the small intestine were not significantly changed. Concentration of 25-OHD in the blood serum and 25-hydroxylase D3 activity in the liver decreased in rats given T-2 toxin. Formation of 1,25(OH)2D3 and 24,25(OH)2D3 in the kidneys was not significantly changed, while T-2 toxin inhibited regulatory changes in 1-hydroxylase 25-OHD3 activity in response to the action of PTH and adenylate cyclase activator forskolin. The results of the investigation have evidenced that calcium metabolism disorders during chronic action of mycotoxins could be partially associated with secondary vitamin D deficiency.