[Investigation of the role of Zn2+ and zinc-containing proteins in the pathogenesis of bone inflammmation (the case of periodontitis)].

The levels of Ag, Al, Bi, Co, Cr, Fe, Mo, Si in osseous tissue of periodontium of domestic cats decreased in case of periodontitis in comparision with those of a healthy animals. At the same time the level of Zn increased dramatically. The level of tagged [14C] glycine in protein of bones of periodontium increased twofold and [35S] methionine 1,54 times which is explained by the fact of predominance of I type collagen in which one third of amino acids is represented by glycine while sulfur-containing amino acids are virtually absent. The latter are contained in non-collagenous proteins of bones of periodontium contributing for its metabolism. The difference in tagged aminoacids inclusion in bones of periodontium is mainly provoked by redistribution of the collagen and non-collagenous proteins.

[A new view on pathochemical mechanisms of prolonged peritoneal dialysis].

New data on etiology, pathogenesis, clinics, quantity estimation, treatment and complications of peritoneal dialysis are observed. The role of aquaporine, nitric oxide, NO-synthase, inflammation and sepsis markers (procalcitonine, C-reactive protein) in pathochemical mechanism of peritoneal dialysis is discussed.

Study of drug transport between the blood and lymph in the predominant direction.

Our method for evaluating the time course and intensity of antibiotics and other drugs transport in the predominant direction between the blood and lymph in humans promotes a more objective evaluation of drug circulation mechanisms, which is essential for determining the time of their repeated administration and route of administration. Calculation of the lymph/blood difference coefficient, based on parallel repeated measurements of the drug concentration in the lymph and blood, and of the lymph/blood coefficient provides complete data on the direction and time course of drug transport between the lymph and blood in the predominant direction.

[Effects of high quantities of sorbitol and saccharose in the diet on enzymes activity and liver mass of rats in different seasons of the year].

Four groups of 1-month-old rats were fed with standard diet (SD) for a month, 46% SD + 54% sorbitol, 54% saccharose or 27% sorbitol + 27% saccharose. Fed with 54% sorbitol and with 27% sorbitol + 27% saccharose differed from rats given 54% saccharose and 100% SD (they were thin, had hyperreaction to light, diarrhea). Liver mass in all the tests in autumn and winter (AuWi) is lower than in spring and summer (SpSu). It is lower in 54% sorbitol, higher in 27% sorbitol + 27% saccharose, the highest in 54% saccharose and 100% SD. Specific activity (SA) of lactate dehydrogenase (LDG) is higher, glucose-6-phosphate dehydrogenase (G-6-PDG) is lower in SpSu than in AuWi in 4 diets. In 54% sorbitol and 27% sorbitol + 27% saccharose SA of LDG, G-6-PDG and succinate dehydrogenase (SDG) is not higher than in 100 SD. SA of SDG and LDG in SpSu is higher than in AuWi, G-6-PDG is lower in SpSu. SA of these three enzymes is not higher in 54% sorbitol than in 100% SD in contrast to 4-fold rise of SA of sorbitol dehydrogenase. Biorhythms of enzyme SA reflect the results of interaction of adaptive molecular mechanisms of the body, including genetic ones, with changing environment.

Biorhythms of activities of liver and blood dehydrogenases and changes in body weight of the rats feeding normal diet or excess of sugar substitutes.

Biorhythms with higher levels of activity of sorbitol dehydrogenase and lactate dehydrogenase in blood plasma, specific activity of sorbitol dehydrogenase, lactate dehydrogenase, and malate dehydrogenase in the liver, and body weight of rats were more pronounced in the spring-summer period than in the autumn-winter period. These specific features were revealed in animals feeding a normal diet or food with 54 and 27% sugar substitute sorbitol. However, specific activity of glucose-6-phosphate dehydrogenase in the liver was higher in the autumn-winter period. Activity of sorbitol dehydrogenase in blood plasma increased by tens of times due to induction of sorbitol synthesis (substrate) in the liver. Sugar substitute xylitol is structurally similar to sorbitol, but is not the substrate for sorbitol dehydrogenase. However, the effect of xylitol on activities of lactate dehydrogenase, malate dehydrogenase, and glucose-6-phosphate dehydrogenase in the spring-summer period was similar to that of sorbitol.

[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. Input % (ratio pulse/min in bone and blood serum) and RRA in 1 week increased sharply, decreased in 2 weeks and less changing in 4 weeks. After fracture CD(RRA) in traumatized mandible and non traumatized femur in rats were changing in the opposite directions that testifies to the different prevailing directions of marked substances transport between blood and bones.

A method for evaluating the fluctuations in the intensity of substance transport between blood and bones in the predominant direction.

The dynamics of fluctuations in the intensity of the blood-bone flow of substances in the predominant and opposite directions was evaluated using the percent radioactivity difference coefficient and its graphic presentation. The technology of calculating this coefficient is described.

Effect of parathyroidectomy on fluctuations in calcium transport between the blood and mineralized tissues of rats.

Parathyroidectomy increases the degree of(45)Ca fluctuations between the blood and mineralized tissues (bones and teeth) in rats, which is associated with a decrease in 14C-glycine incorporation into bone proteins. Disturbances in Ca(2+)metabolism and transport during hyperparathyroidism are partly prevented by parathyroidectomy. It is mainly related to variations in the interaction of parathyroid hormone, calcitonin, 1.25(OH)2D3, and other bioactive substances, but not to initiation of mineralization with protein matrixes.

A new method for evaluation of radioactive label transport intensity in the predominant direction between blood and liver.

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.

[Effect of cariesogenic diet and age on selenium distribution between blood and mineralized tissues in rats]. / Vliianie kariesogennoi diety i vozrasta na raspredelenie selena mezhdu krov'iu i mineralizovannymi tkaniami krysy.

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. In 3-month-old rats receiving common fodder the peak of all RRA was delayed to 12-48 h postinjection, the values decreasing by 192 h. The peak of specific activity (SA) of (75)Se protein in the bones was recorded 24 h and its decrease 192 h postinjection. In one-month-old rats receiving sucrose-casein diet during 2 months all RRA and SA after 6 and 12 h and part of RRA after 24 h were higher than in the control, that is, Se absorption by bones and teeth from the blood decreased.

Effects of selenium-containing compounds and their metabolism in intact rats and in animals with bone fractures.

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.

[Study of age-specific changes in labeled citrate metabolism in health and disease]. / Issledovanie vozrastnykh izmenenii metabolizma mechenogo tsitrata v norme i pri patologii.

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 biphasic reaction with a rapid elevation and decrease after 1-2 h and a second elevation before the end of the experiment due to citrate adsorption on hydroxyapatite and influence of D and R proteins on stable hemosorption of citrate by MT was observed. The time course of RRA enamel/oral fluid was different: a decrease 1 h postinjection and an increase 2-3 h postinjection. Two weeks after crossing the inferior alveolar nerve, the R/BS RRA decreased to a lesser degree in 1-month-old rats in comparison with 3-month-old animals, which can be explained by higher efficiency of the adaptive-compensatory mechanisms in growing rats.

Study of labeled carbonate metabolism in healthy organisms during reparative osteogenesis and denervation by the bone/plasma index.

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.

Labeled citrate metabolism in bone fractures and impaired innervation.

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.

[A new bone/blood index in the study of labelled citrate metabolism in rat bones in fracture, deafferentation, rickets, and caries]. / Novyi koéffitsient kost'/krov' v izuchenii metabolizma mechenogo tsitrata v kostiakh krys pri perelome, deafferentatsii, rakhite i kariese.

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. This was established by the study of time course of the labelled citrate in intact rats of different age as well as in fracture and bone innervation defect, in rickets and dental caries. The proposed index can be applied in investigation of various diseases.