Effects of a definite stress on the enzyme activities in blood plasma in mice (author's transl)

The present study was designed to analyze the effects of a short term stress on the quantitative levels of alkaline phosphatase (AP), creatine phosphokinase (CK), aldolase (ALD), lactate dehydrogenase (LDH), and lactate dehydrogenase-1-isoenzyme (LDH 1) during 24 h after stress. For all the enzymes studied higher values for the activity were found due to stress in comparison to the activity level before the stress. The period during the 24 h after stress to reach maximum activity depends on the enzyme and in part on the sex of the animal.     

Superoxide dismutase activity in the Spanish population

Superoxide dismutase is an enzyme that catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. This superoxide radical is produced by all aerobic cells as a normal metabolic intermediate of molecular oxygen, and is dangerous for the cell because it induces the inactivation of various enzymes, lipid peroxidation and mutations. Superoxide dismutase can therefore be considered as a protective enzyme. The purpose of this work was to determine the level of superoxide dismutase activity in the Spanish population, and to study the factors that influence this activity. The superoxide dismutase activity of 2397 individuals was determined using the method described by Minami and Yoshikawa. The superoxide dismutase activity level in the adult Spanish population was found to be 4.16 +/- 0.89 Units/ml of blood. No significant variations with respect to sex were detected. But it was observed that the superoxide dismutase activity level was 9% higher in the young urban Spanish population.     

Superoxide dismutase activity in the Spanish population

Summary Superoxide dismutase is an enzyme that catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. This superoxide radical is produced by all aerobic cells as a normal metabolic intermediate of molecular oxygen, and is dangerous for the cell because it induces the inactivation of various enzymes, lipid peroxidation and mutations. Superoxide dismutase can therefore be considered as a protective enzyme. The purpose of this work was to determine the level of superoxide dismutase activity in the Spanish population, and to study the factors that influence this activity. The superoxide dismutase activity of 2397 individuals was determined using the method described by Minami and Yoshikawa. The superoxide dismutase activity level in the adult Spanish population was found to be 4.16±0.89 Units/ml of blood. No significant variations with respect to sex were detected. But it was observed that the superoxide dismutase activity level was 9% higher in the young urban Spanish population.     

Auswirkungen einer definierten Belastung auf die Enzymaktivitäten im Blutplasma bei der Maus Effects of a definite stress on the enzyme activities in blood plasma in mice

Summary The present study was designed to analyze the effects of a short term stress on the quantitative levels of alkaline phosphatase (AP), creatine phosphokinase (CK), aldolase (ALD), lactate dehydrogenase (LDH), and lactate dehydrogenase-1-isoenzyme (LDH 1) during 24 h after stress. For all the enzymes studied higher values for the activity were found due to stress in comparison to the activity level before the stress. The period during the 24 h after stress to reach maximum activity depends on the enzyme and in part on the sex of the animal.     

Distribution of tunichrome and vanadium in sea squirt blood cells sorted by flow cytometry

Specialized blood cells of many tunicates accumulate high concentrations of vanadium and phenolic peptide pigments called tunichromes (TC). In order to determine whether V and TC reside in the same cells, Ascidia nigra and Ascidia ceratodes blood cell subpopulations were isolated by fluorescence-activated cell sorting (flow cytometry) and chemically analyzed. V was found in the spherical, green/grey signet ring cells, and to a lesser degree in the mulberry-shaped, yellow/green morula cells (MRs), whereas free TC was detected mainly in MRs.     

Lamellipodia mediate the heterogeneity of central olfactory ensheathing cell interactions

The growth and guidance of primary olfactory axons are partly attributed to the presence of olfactory ensheathing cells (OECs). However, little is understood about the differences between the subpopulations of OECs and what regulates their interactions. We used OEC-axon assays and determined that axons respond differently to peripheral and central OECs. We then further purified OECs from anatomically distinct regions of the olfactory bulb. Cell behaviour assays revealed that OECs from the olfactory bulb were a functionally heterogeneous population with distinct differences which is consistent with their proposed roles in vivo. We found that the heterogeneity was regulated by motile lamellipodial waves along the shaft of the OECs and that inhibition of lamellipodial wave activity via Mek1 abolished the ability of the cells to distinguish between each other. These results demonstrate that OECs from the olfactory bulb are a heterogeneous population that use lamellipodial waves to regulate cell–cell recognition.     

Long-term production and culture of clones of human T-lymphocytes

Culture of blood T lymphocytes collected from normal individuals and cancer patients were carried out in presence of T cell growth factor (TCGF); these cultures presented cytotoxic activity directed against different targets (lectin activated cells, autologous cancer cells, antibody coated cells and K 562). In order to study separately the different effector subpopulations, isolation of single cultured cells were performed with the help of a micropipette under microscope and monoclonal cultures were carried out in presence of TCGF. In the preliminary cytotoxic assays performed in the clones: (1) a marked activity directed against lectin targets was observed in many clones and (2) an important N K activity was exhibited by the clone 45 B9 (65% of the tested cells lysed human lymphoma K 562 cells).     

Lactate dehydrogenase and glutamate dehydrogenase activities in the circumventricular organs of rat brain following neonatal monosodium glutamate

Glutamate (glu) an excitatory neurotransmitter amino acid, is present in high concentrations in the mammalian central nervous system and is the most abundant amino acid in our daily diet. In the present study the activities of lactate dehydrogenase (LDH) and glutamate dehydrogenase (GDH) were evaluated in the circumventricular organs (CVO) of the brain in 25-day-old rats following MSG administration at a dose of 4 mg/g b.wt during the first ten days of life. The results show the LDH activity increased to 265% of that in the control (p<0.001), whereas GDH activity was significantly decreased (p<0.05), The great elevation in LDH, a cytoplasmic marker enzyme, is apparently due to cytoskeletal changes brought about as a consequence of glu toxicity, whereas lowered GDH activity indicates altered glu homostasis in the blood-brain-barrier deficient areas following neonatal exposure to glu.     

Regional distribution of lactate dehydrogenase isoenzymes in adult rat brain.

The highest lactate dehydrogenase (LDH) activity was found in thalamus, statistically significantly less in cerebral and cerebellar cortex and the lowest in pons. LDH1 and LDH4+5 represented 58% and 23% of the total activity in cerebral cortex, 54% and 20% in thalamus, 42% and 4% in cerebellar cortex and 55% and 7% in pons, respectively.     

Transfer of genetic information from T to B human lymphocytes during an immune response to herpes simplex virus]

Human blood lymphocytes carrying different allotypes were divided into B and T subpopulations and cultured in presence or in absence of ultraviolet inactivated Herpes Simplex Virus. Isolated B or T cells did not produce any antiherpetic activity. The B lymphocytes cultured in presence of 1 or 50% of the supernatant collected from virus exposed T cells synthesized on antiherpetic antibody with some allotypic markers of the T cell donor.     

Histochemical response of alkaline phosphatase activity during the healing of cutaneous wounds in a cat-fish

Summary The activity of alkaline phosphatase in the various tissue components of the regenerating skin of a cat-fish has been studied. A marked increase in alkaline phosphatase activity in the cells of migrating epithelium has been correlated with their highly active state. High alkaline phosphatase in the basal cells after 2 days has been found to have played an important role in cell multiplication and differention. The functional significance of this enzyme is discussed in relation to the granulation tissue formation.     

Action of various progestational hormones on the electric activity of the rat myometrium in pregnancy after biovariectomy

8-day-pregnant rats were ovariectomized, then injected im with progestagens and estrogens while their uterine motility and electrical activity were being recorded simultaneously with a strain gauge and 2 bipolar electrodes. The injections, known to maintain pregnancy after ovariectomy, were progesterone 50 mg/kg, progesterone with estradiol 5 mcg/kg, or medroxyprogesterone acetate 25 mg/kg. Base line recordings for 20 minutes showed the normal pregnant state of brief periods of synchromous electrical and mechanical activity. After ovariectomy, untreated controls exhibited increased duration of synchronized mechanical and electrical activity and height of contractions. When any of the 3 progestagen treatments coincided with ovariectomy, synchrony was decreased and the intervening interval lasted longer. These procedures demonstrated how quickly the hormonal deficit due to ovariectomy is compensated for when ablation is performed before placental progesterone synthesis has begun.     

A single tryptophan residue of endomannosidase is crucial for Golgi localization and <Emphasis Type="Italic">in vivo</Emphasis> activity

Golgi-endomannosidase provides an alternate glucosidase-independent pathway of glucose trimming. Activity for endomannosidase is detectable in various tissues and cell lines but not in CHO cells. Cloning of CHO cell endomannosidase revealed that the highly conserved Trp188 and Arg177 of vertebrate endomannosidase were both substituted by Cys. The Trp188Cys substitution was functionally important since it alone resulted in endoplasmic reticulum (ER) mislocalization of endomannosidase and caused the greatly reduced in vivo activity. These effects could be reversed in cells with a back-engineered Cys188Trp CHO cell endomannosidase, in particular N-glycans of α1-antitrypsin became fully processed. The intramolecular disulfide bridge of CHO cell endomannosidase formed with the additional Cys188 was not solely responsible for the reduced enzyme activity since endomannosidase with engineered Cys188Ala or Ser substitutions did not restore enzyme activity and was ER mislocalized. Thus, the conserved Trp188 residue in endomannosidases is of critical importance for correct subcellular localization and in vivo activity of the enzyme. Received 7 May 2007; received after revision 31 May 2007; accepted 11 June 2007     

Limited proteolysis of lactate dehydrogenase from procine heart with trypsin: Characterization and reactivation of the fragments

Summary The ternary complex formed by native lactate dehydrogenase (LDH) from porcine heart, NAD⁺ and sulfite, was digested with trypsin over a period of 12–16 h³. After removal of the ligands and residual native lactate dehydrogenase by ion exchange chromatography dimers were obtained which were almost inactive. The dimers were lacking a hexapeptide at the N-terminus; however, the secondary structure was the same as that of native lactate dehydrogenase. The circular dichroism spectra showed a dependence on temperature which suggested an equilibrium of two different structural states.The reaction of antibodies against native porcine heart LDH with the dimers restored the catalytic activity, and subsequently the dimers behaved similarly to the native enzyme. Addition of 1 M phosphate or NAD-sulfite to the dimers restored 80–90% of the catalytic activity. It could be demonstrated that the behaviour of the reactivated dimers, in contrast to that of the inactive dimers, was similar to the behaviour of native lactate dehydrogenase. For instance, ultracentrifugal analysis showed that dimers reactivated with NAD–SO₃ ^– were associated to give tetramers.The reaction of antibodies against native LDH with the dimers reactivated with NAD–SO ₃ ^– demonstrated that the native LDH and the dimers have the same surface determinants.     

Superoxide dismutase activity decreases during erythrocyte aging

Summary Superoxide dismutase activity was determined by the adrenalin method in bovine erythrocytes separated according to age. Progressive loss of the enzyme activity was found, down to ca 65% of that of the youngest cells.     

Cell cycle patterns of thymidylate synthetase and 5,10-methylenetetrahydrofolate polyglutamates in cultured mouse hepatoma cells

Summary The regulation of thymidylate synthetase activity was investigated throughout the first cell cycle after release from an isoleucine block in synchronous cultures of mouse hepatoma (Hepa) cells. Activity in cell extracts increased with the onset of S phase and the increased activity was attributed to a parallel increase in enzyme concentration as determined by titration with tritiated fluorodeoxyuridylate. The polyglutamate chain length of reduced folate cofactors, which could also influence thymidylate synthetase activity, was unchanged.Acknowledgments. Supported by grant CA 22754, awarded by the National Cancer Institute, DHEW.     

Ovarian LDH activity in gonadotropin-treated immature rats.

Lactate dehydrogenase (LDH) activity was studied in the ovaries of immature rats treated with pregnant mare serum gonadotropin (PMS). LDH activity increased sharply at 36 h after PMS injection in the ovarian tissue as well as in the blood. It was suggested that the increase of LDH activity in the ovary may be related to its increasing ability to secrete estrogen.     

Cytogenetic evidence for hemizygosity at the thymidine kinase locus in P388 mouse lymphoma cells

A detailed cytogenetic investigation was carried out on P388 mouse lymphoma cells. The cells have a mean chromosome number of 36.86 with a mode and median of 37 chromosomes. G-banding analysis of 12 spreads revealed a total of 15 marker chromosomes with chromosome 11, the determinant of thymidine kinase, being present only in single copy per cell. It is therefore concluded that the P388 cell line is hemizygous at the thymidine kinase locus. Thymidine kinase activities were assayed in P388 cells and two other malignant cell lines, clone 707 Friend mouse leukaemia cells and L5178Y mouse lymphoma cells. No clear relationship was observed between enzyme activity and gene dosage.