[Influence of mandibular fracture upon intensity and prevailing direction of carbonate and citrate transport between blood and bones].

Using new coefficient of the difference relative radioactivity (CD(RRA)) bone/blood there was studied [(14)C]-carbonate and [3-(14)C]-citrate in 1-month and 6-months rats after right-side fracture of the mandible in prevailing direction between blood and bone. Animals were taken out from the experiment 20 min after intraperitoneal injection of [(14)C]-carbonate and [3-(14)C]-citrate on 7th day after (stage of cell-fibrous callosity), on 14th day after (stage of chondroid callosity) and on 28th day after (stage of the primary bone callosity) the experiment start. Changes after injections of marked citrate and carbonate were similar.

[Effect of cariesogenic diet and age on selenium distribution between blood and mineralized tissues in rats].

The distribution of Se in the blood and teeth (in the jaw and femoral bones) was evaluated using a new coefficient of relative radioactivity (RRA), representing the ratio of (75)Se in the teeth (bones) and blood. Changes in all RRA were studied during 1-192 hours after intraperitoneal injection of [(75)Se]selenate in one-month-old rats receiving common fodder; a biphasic pattern of changes was observed, with peaks 6 and 48 h and lowering 24 and 192 h postinjection. The first peak was mainly due to Se adsorption on hydroxyapatite, the second to chemo-adsorption on it and Se binding to protein.

[Study of age-specific changes in labeled citrate metabolism in health and disease].

A new coefficient - mineralized tissues/biological fluids (MT/BF) - is suggested for evaluating the distribution of compounds adsorbed by MT and dissolved in BF. The relative radioactivity (RRA) was estimated for the periods of 10 min to 96 h after intraperitoneal injection of [3-(14)C]citrate to rats aged 1 and 3 months and over 1 year by dividing the percent of incorporation in MT by the percent of incorporation in BF. Changes in RRA for molar root/blood serum (R/BS) and RRA for dentin/blood serum (D/BS) are similar: low values at the beginning of experiment, an increase 1 h postinjection, a decrease 2-3 h postinjection, and another increase (65-80 times) by 96 h postinjection.

[A new bone/blood index in the study of labelled citrate metabolism in rat bones in fracture, deafferentation, rickets, and caries].

A new bone/blood index has been developed which is calculated by dividing % of radionuclide inclusion in the bones by % of the inclusion in the serum. Graphic image of the index changes with time is significantly more demonstrative than digital tables and allows one not only easily measure distribution of the labelled compound between fractions diluted in the blood and sorbed on the bone but also specify a major direction of their transport between blood and bone. The index confirms the presence of biphasic primary fast but weak physical adsorption and secondary slow and strong chemisorption.