[24-hour fluctuations of the values of certain components of the saliva and dental plaque in school children]. / Wahania dobowe wartosci niektórych skladników sliny i plytki nazebnej u dzieci szkolnych.

24-hours changes were studied in the saliva and dental plaque of the concentrations of total fluorine, inorganic phosphate and protein, and of pH value. The study was carried out in two groups of school children: I--control, II--subjected to contact fluoridation. The obtained results showed that circadian changes occurred in controls and in children subjected to fluoridation.

Effects of N- and C-terminal fragments of substance P on ATPase and monoamine oxidase activities in rat brain.

The in vitro influence of substance P (SP) C- and N-terminal fragments on the Na+,K(+)-ATPase and Ca2+,Mg2(+)-ATPase and monoamine oxidase (MAO) from synaptosomal membrane and extra-synaptosomal mitochondria were studied. The obtained results indicate: 1. C-terminal fragment of SP (SP6-11) in 10 microM concentration stimulates the Ca2+,Mg2(+)-ATPase activities from cerebral cortex and hippocampus. Na+,K(+)-ATPase from cerebral cortex is hardly sensitive to the action of this fragment. 2. N-terminal fragment of SP (SP1-5) in 10 microM concentration increases Na+,K(+)-ATPase activity from cerebral cortex and hippocampus. 3. N-terminal tetrapeptide (SP1-4) exerts no influence on ATPases independently from their brain localization. 4. The activity of monoamine oxidase after use of C- and N-terminal fragments is unchanged.

Effects of analogues of substance P fragments on the MAO activity in rat brain.

The influence in vitro of analogues of Sp5-11 and SP6-11 substance P fragments on the activity of monoamine oxidase (MAO) in homogenates and crude mitochondrial fractions of rat brain was examined. The rat brain was divided into: I--cerebral cortex, II--hippocampus, III--midbrain, IV--thalamus with hypothalamus, V--cerebellum and VI--medulla oblongata. The obtained results proved that the analogues of SP fragments inhibit selectively the activity of the enzyme in the homogenates of cerebral cortex, hippocampus, midbrain and cerebellum. In the crude mitochondrial fractions the applied analogues of SP fragments caused a slight increase of the enzyme activity. The most significant changes in the activity of MAO were observed in hippocampus homogenate fraction.

The effect of chloramphenicol and cycloheximide on the activity of enzyme "markers" of mitochondrial substructures of the rat liver.

Chloramphenicol and cycloheximide exert in vivo inhibitory effects on the synthesis of mitochondrial enzymes. Choloramphenicol action results in a significant decrease of the activity of enzymes being the "markers" of all submitochondrial structures including that of the outer membrane. This suggests that chloramphenicol affects biosynthesis of of "assembly protein" on mitochondrial ribosomes and thus affects incorporation of proteins, wherever they are synthesized, into the structure of the mitochondrion as a functional entity. The effect of cycloheximide depends markedly on the concentration of the inhibitor and on the time of its administration. The differences in sensitivity of examined enzymes to the drug are probably related to their differential turnover.

Investigation of localization of monoamine oxidase (EC 1.4.3.4) in subfraction of rat liver mitochondria.

Subfractionation of the purified preparations of mitochondria was performed according to Schnaitman's digitonin method. In some experiments, polyvinyl sulphate (PVS) was added to the medium during the preparation and subfractionation of mitochondria. The formation of the "fluffy layer" was not observed in the presence of PVS. The "fluffy layer" was either removed or left within the pellet during the separation of the subfraction of mitoplasts from the supernate containing the outer membrane as well as the inter-membrane space. The monoamine oxidase (MAO) activity was determined by means of our own modification of Tabor's method. In this way the influence of aldehyde oxidase upon the obtained results could be eliminated. A part of MAO activity was found in the subfraction of mitoplasts both in the presence and absence of PVS in the medium. The obtained results suggest double localization of MAO both in the outer and inner membrane. The influence of the method of determination of MAO activity on the evaluation of its intra-mitochondrial activity has been discussed.