Blood content of MDA in rats increased 1 and 2 weeks after mandibular bone fracture at stages of cellular fibrous and chondroid callus and decreased 4 weeks after fracture at the stage of primary bone callus. Treatment with Se (intragastrically and electrophoretically) reduced this increase by activating selenium-containing glutathione peroxidase. In order to clear out the relationship between Se and carbohydrate metabolism in different ages, the distribution of Se between the blood and mandibular bone, diaphysis and metaepiphyseal zone of the femoral bone was studied using the bone/blood relative radioactivity coefficient after intraperitoneal injection of [(75)Se]selenate. In control 1-month-old rats the radioactivity had 2 peaks corresponding to 6 and 48 h. The first peak was presumably caused by Se adsorption on hydroxyapatite, the second by chemosorption on hydroxyapatite and protein binding. Only one peak of relative radioactivity (after 12-48 h) was observed in 3-month-old control rats, and it could be increased by sucrose diet. The relative radioactivity was higher in rats receiving sucrose ration for 2 months starting from the age of 1 month in comparison with the control.

Changes in (14)C incorporation into regenerate after bone fracture and impairment of mandibular innervation, and injection of [3-(14)C]cytrate corresponded to the stages of reparative osteogenesis: after 1 week (14)C incorporation in the cellular-fibrous callus surpassed its release, after 2 weeks the rates of (14)C incorporation and release in the chondroid callus become similar, and after 4 weeks the release of the label predominated in the primary bone callus. Denervation reduced (14)C incorporation into regenerate, which impaired bone remodeling. Citrate in the bones is characterized by high metabolic activity.

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The intensity of 75 Se transport in the predominant direction after intraperitoneal injection of [ 75 Se]selenate was compared in 1-and 3-month-old rats receiving common vivarium ration or sucrose diet. The incorporation percent, blood/liver relative radioactivity, and relative radioactivity difference coefficient were evaluated in the blood and liver. The dynamics of label incorporation in the blood of rats fed common diets has two peaks (at 1-3 h and 12-24 h) and a drop at 6 h. Coefficient of difference in 1-month-old rats was characterized by a greater amplitude of fluctuations than in 3-month-old animals. . Address for corre spondence: kichenko@metronet.ru. S. M. Kichenko New methods for evaluation of compounds and atom transport can provide useful data for laboratory experiments and clinical diagnosis.The study of the transport of Se compounds is important [1,2,4,5,8]. The time of biological half-life of Se compounds in rat liver changes with age [6]; Se modifies the blood glucose level, gluconeogenesis intensity, and glycogenolysis in the liver of intact rats, in humans with diabetes and in rats with streptosotocin diabetes [7,[9][10][11][12]. However, there are no precise data on the intensity of Se transport between the blood and liver in the predominant direction during certain periods of time, which can be valuable for experimental and clinical medicine.The aim of this study was to develop a new method for evaluating the dynamics of 75 Se transport intensity in the predominant direction from the blood into the liver and vice versa. Age-specific differences in Se metabolism and relationship between carbohydrate and Se metabolism were studied. MATERIALS AND METHODSTotal 75 Se levels in liver homogenates and blood of rats 1, 3, 6, 12, 24, 48, and 192 h after intraperitoneal injection of [ 75 Se] sodium selenate (20,000 cpm/g) were evaluated by γ-irradiation of the sum of Se-containing compounds using a radiometer with a scintillation pickup with a Tl-activated KI crystal. The percent of 75 Se incorporation was estimated by the ratio of cpm/g tissue or 1 ml blood to cpm/g. The relative radioactivity (RRA) was estimated by the formula (1): % of incorporation in liver RRA=(1) % of incorporation in blood After a certain period after injection of the labeled compound, RRA was estimated by formula 1, and after fixed periods RRA 2 , RRA 3 , and RRA n were estimated.Then the predominant direction of 75 Se transport was determined and the difference between the trans-

We studied the effect of mandibular fracture and denervation on [(14)C]carbonate metabolism. A new index (bone/plasma relative radioactivity) reflecting the ratio between (14)C incorporation into bone and plasma was proposed. The percentage of label incorporation and bone/plasma relative radioactivity were measured from the 5th minute to the 192nd hour after intraperitoneal injection of labeled carbonate to 1-2-month-old albino rats. We revealed a biphasic reaction: rapid accumulation and elimination of the isotope form the bone; and slow accumulation followed by slow accumulation and elimination. Changes in carbonate metabolism after bone fracture corresponded to phases of reparative osteogenesis. At the stage of cellular-and-fibrous callus accumulation of labeled carbonate dominated over its elimination. At the stage of chondroid callus elimination dominated over accumulation. At the stage of primary osseous callus elimination dominated over accumulation, but did not surpass the control level. After fracture the index of bone/plasma relative radioactivity underwent general changes that were most pronounced in the zone of trauma. After denervation this index also decreased.