Concentration of the cross-linked carboxyterminal telopeptide of type I collagen in serum of young growing rats fed a low calcium and vitamin D-deficient diet.

Type I collagen is the main type found in mineralized bone. Specific radioimmunoassay for the cross-linked carboxyterminal telopeptide of type I collagen allows assessing the degradation of type I collagen in serum samples. The aim of the present investigation was to determine the concentration of cross-linked carboxyterminal telopeptide of type I collagen in serum of dietary calcium and vitamin D-deficient rats, a good model disease of decreased formation and mineralization of bone matrix and excessive bone resorption. The studies were carried out on 20 young growing Wistar rats. Serum concentration of the cross-linked carboxyterminal telopeptide of type I collagen was analyzed by the Rat Telopeptide [125I]ICTP Radioimmunoassay Kit obtained from Orion Diagnostica (Finland). The data obtained from biochemical analysis showed increased concentration of the cross-linked carboxyterminal telopeptide of type I collagen in the serum of rats fed a low calcium and vitamin D-deficient diet after 14 days of the experiment. At the end of the experiment (day 21), the concentration of carboxyterminal telopeptide of type I collagen in serum was still elevated in these animals. In conclusion, dietary calcium and vitamin D-deficiency in rats produces hypocalcaemia together with the increased concentration of the cross-linked carboxyterminal telopeptide of type I collagen in serum.