[Effect of inhibitors of energy-dependent Ca2+-transporting systems on ATP-hydrolase activity of smooth muscle actomyosin]. / Vliianie ingibitorov énergozavisimykh Ca2+-transportiruiushikh sistem na ATP-gidrolaznuiu aktivnost' aktomiozina gladkoi myshtsy.

Comparative investigation of of smooth muscle actomyosine ATP-ase sensitivity to some inhibitors of energy-dependent Ca(2+)-transporting systems has been carried out. It is proved that the ATP-ase of actomyosine is nonselectively inhibited by thapsigargin (imaginary inhibition constant Ki is equal 29.4 +/- 5.2 nM), cyclopiazonic acid (Ki = 626 +/- 118 nM), eosin Y (Ki = 70 +/- 14 nM) and p-chlormercurybenzoate (Ki = 380 +/- 151 nM). The data obtained could be used for the further development of the ideas about regularities of Ca(2+)-dependent control of the smooth muscles contraction-relaxation.

[Effect of incubation medium dielectric permeability on enzymatic activity of functionally different ATPases of smooth muscles]. / Vliianie diélectricheskoi pronitsaemosti sredy inkubatsii na fermentativnuiu aktivnost' funktsional'no razlichnykh ATP-az gladkoi myshtsy.

Some organic solvents (2-10%) have been comparatively studied for their effect on purified transporting Ca2+, Mg(2+)-ATPase, solubilized from the plasma membrane of smooth muscle cells and on actomyosine ATPase of the smooth muscle. The inhibiting effect of solvents on the initial maximum specific activity of Ca2+, Mg(2+)-ATPase corresponds to the sequence dioxane > acetone > ethanol > dimethyl sulfoxide (DMSO). Like the case with Ca2+, Mg(2+)-ATPase, dioxane inhibits actomyosine ATPase; acetone, ethanol and DMSO stimulate ATP-hydrolase reaction which is catalyzed by the complex of contractile proteins. It is proved that the effect of the decrease of ATPase activity with decrease of incubation medium polarity is exceptionally determined by the value of incubation medium the dielectric permeability. This effect is independent of chemical nature of organic solvents which were used with the aim to obtain the corresponding values of D. It is supposed that the cause of activity inhibition of solubilized transporting Ca2+, Mg(2+)-ATPase under the effect of dioxane, acetone, ethanol and inhibition of activity of actomyosine ATPase as affected by dioxane is mainly connected with the increase of electrostatical interaction between opposity charged active centre of ATPase and the product (products) of ATP-hydrolase reaction (Mg ADP-, HPO4(2-)), which is induced by the decrease of incubation medium polarity (the decrease of D value). Stimulating effect of acetone and ethanol on actomyosine ATPase is probably determined by superposition of two components: that connected with direct effect of these solvents on the protein catalyst (interaction with enzyme with the future break of hydrogen and hydrophobic bonds in the protein and its "fluffing") and "electrostatic component" determined by the change of D value of the incubation medium. Possible role of electrostatic interactions between ATPases and reagents as the factor of non-specific control of catalytic activity of these enzymes is discussed.

[Effect of temperature on superprecipitation of actomyosin of myometrial smooth muscle and reactions of ATP hydrolysis catalyzed by this protein]. / Vliianie temperatury na superpretsipitatsiiu aktomiozina gladkoi myshtsy miometriia i reaktsiiu gidroliza ATP, kataliziruemuiu étim belkom.

The experiments carried out on the preparation of myometrium actomyosin were carried out. The reaction of superprecipitation of this protein and ATP hydrolysis were studied as affected by temperature. For the both processes the value of temperature optimum is 45 degrees C. The value of activation energy Ea is equal to 20 +/- 3 and 23 +/- 3 kJ/mol for the reaction of superprecipitation and ATP hydrolysis, respectively. Preincubation of actomyosin (45-60 degrees C, 1-5 min) in the medium not including ions of Ca, Mg and ATP with following introduction of the components to this medium and ten-minute incubation of protein in it causes the inhibition of the both reactions at the incubation temperature 45 degrees C and their stimulation at the incubation temperature 55 and 60 degrees C. Data obtained are discussed with regard for the structure organization of actomyosin of the smooth muscle.

[The calcium pump in the sarcolemma controls smooth muscle relaxation]. / Kal'tsievyi nasos sarkolemmy kontroliruet rasslablenie gladkoi myshtsy.

In order to identify the functional role of the sarcolemma calcium pump in the control over smooth muscle relaxation there was studied the effect of temperature on relaxation kinetics of myometrium carbachol contracture, actomyosin superprecipitation isolated from this object and Mg2+, ATP-dependent transport of Ca2+ in the fraction of uterus sarcolemma vesicles. The activation energies of the processes under study were determined in comparison. It was concluded from the evidence obtained that relaxation of the smooth muscle contracture is controlled by the stimulated temperature increase and by Na(+)-independent trans-sarcolemma release of Ca2+ from the myocytes sensitive to La3+ effect. The release is provided by the calcium pump of the plasmic membrane.

[Reaction of glycine with acetoacetate and various properties of the catalyzing enzyme from the rat liver]. / Reaktsiia glitsina s atsetoatsetatom i nekotorye svoistva kataliziruiushchego ee fermenta iz pecheni krys.

The enzymic interaction between acetoacetate and glycine which are added outside is established to occur in the tissue homogenates of the liver, kidneys and spleen of rats. The interaction leads to a decrease of the both components in the equivalent quantities. Homogeneous crystalline preparations of the enzyme catalyzing the above mentioned reaction are isolated from the liver tissues and purified. Certain properties of the enzyme are studied.

[Effect of carbostimulin on reparative osteogenesis in rabbits of different ages]. / O vliianii karbostimulina na reparativnyi osteogenez u krolikov razlichnogo vozrasta.

Rate of reparative osteogenesis was studied after partial resection of rabbit radius bone. Within 15 days of the restoration period the content of dry residue was increased by 26%, 17% and 35% in regenerate of 2-months old animals, treated with their mixtures as compared with 6-months old rabbits. Content of calcium was increased 1.5-fold in callus of all the 2-months old animals as compared with that in the 6-months old rabbits.

[Effect of carbostimulin and its mixture with vitamin D3 on the mineralization process of the bone callus in rabbits]. / Vliianie karbostimulina i smesi ego s vitaminom D3 na protsess mineralizatsii kostnoi mozoli krolikov.

Mineralization of rabbit bone callus was studied within 15 days after resection of the upper part of radius bone inder conditions of treatment with carbostimuline and its mixture with vitamin D3. Content of calcium in the bone regenerate was increased by 40.8% after administration of carbostimuline and--by 70.5% after treatment with mixture containing vitamin D3. These preparations caused only slight effects on the phosphorus content. Dry residue in the regenerate os f animals, treated with the preparations, was increased approximately 2-fold (43% and 23%, respectively, p less than or equal to 0.001) as compared with control group. Content of citric acid was distinctly higher in the bone tissue of the treated animals. Within 15 days after the operation content of sialic acids wanormalized in blood serum of the animals. The data obtained were corroborated by X-ray and histologic examinations.

[Effect of carbostimulin and vitamin D3 on activity of glycolytic enzymes of rabbit bones, regenerates and muscles]. / Vpliv (karbostimulinu) ta vitaminu D3 na aktivnist' fermentiv glikolizu v tkaninakh regeneratu, kistok ta m'iaziv kroliv.

Activity of glycolysis enzymes such as: phosphofructokinase, aldolase, phosphoglucomutase, was determined in the regenerate of a bone, bone fragments, native bone and, for the sake of comparison, in the animal muscles after the radius resection and feeding of carbostimulin and its mixture with vitamin D3 for 10 days. On the 12th day after the radius resection the phosphofructokinase activity in rabbits increases in the native and operated bones as compared to that in bones of nonoperative animals. In the group of rabbits which were fed on the mixture of carbostimulin and vitamin D3 the phosphofructokinase activity is 7-2 times as high. In the regenerate of these animals the activity becomes 12 times as high as that in the regenerate of the control rabbits. An analogous increase in the aldolase and phosphoglucomutase reaction rate is observed in the bones of the animals which received carbostimulin and vitamin D3 (4.5 and 7.5 times, respectively). The same tendency to the increase in the activity of these enzymes is observed in the regenerate tissue. In the muscular tissue at this stage of regeneration the activity of the studied enzymes which is usually high in norm decreases.

[Effect of "carbostimulin", vitamin D 3 and their mixture on bone tissue regeneration]. / Vpliv karbostimulinu i vitaminu D3 ta ikh sumishi na regeneratsiiu kistkovoi tkanini.

Healing of the bone injury in rabbits was studied as affected by carbostimulin and its mixture with vitamin D3. Some biochemical indexes: the content of sialic acids, calcium and citric acid in blood serum of the animals, intensity of 14C incorporation from NaH14CO3 into the regenerated bone tissue and its proteins as well as histological studies, data, evidence for a positive effect of the mentioned preparations on the bone substance regeneration in the animals under experiment. So. the content of sialic acids in blood serum normalizes on the 10th day after the operation mostly in the animals which were administered the mixture of the preparations and in which the most pronounced hypercalcemia is observed. Incorporation of 14C from NaH14CO3 into the regenerated tissue and its proteins is most intensive in the same animals.