Gender-related differences of mouse liver d-aspartate oxidase in the activity and response to administration of d-aspartate and peroxisome proliferators

• 1.1. The hepatic d-aspartate oxidase activity was found to be higher in female ddY and ICR mice than in their male counterparts. On the contrary, the free d-aspartate content in the liver was lower in female mice than in male mice, suggesting that d-aspartate is actually metabolized by d-aspartate oxidase in vivo.
• 2.2. Oral administration of d-aspartate to the animals increased the hepatic d-aspartate oxidase activity 2–3 fold in both genders without any significant difference in the rate of the increase between the genders.
• 3.3. Several peroxisomal enzyme activities other than d-aspartate oxidase examined were not affected by this treatment.
• 4.4. Experiments in vitro suggested that the increase in the d-aspartate activity might be explained in part by stabilization of the enzyme by d-aspartate.
• 5.5. The administration of clofibrate, a peroxisome proliferator, to male mice, increased the hepatic d-aspartate oxidase activity with a significant simultaneous decrease of d-aspartate content in the liver, in agreement with a possible role of the enzyme n vivo.
• 6.6. On the other hand, the administration of clofibrate or dehydroepiandrosterone to female mice decreased the d-aspartate oxidase activity.
• 7.7. The peroxisome proliferators were suggested to act to eliminate the gender difference of hepatic d-aspartate oxidase activity in mice.

     

Relationship between brain trehalase activity and trehalosema during direct and diapausing development in Pieris brassicae

• 1.1. Brain trehalase specific activity and trehalosemia were measured during the end of the developmental life cycle in non-diapausing and diapausing insects.
• 2.2. During non-diapausing development, trehalosemia reached maximum values at the beginning of pupal life. Then a constant decrease was observed up to the end of adult life.
• 3.3. The specific activity of brain trehalase was maximum when the insects were in active feeding periods, minimum activity appearing during moulting phases.
• 4.4. During diapausing development, trehalosemia was very high at the beginning of pupal life, particularly when insects were exposed to wintering conditions.
• 5.5. When diapause was broken, trehalosemia fell, announcing adult emergence.
• 6.6. Brain trehalase activity showed the same qualitative variations as in non-diapausing larvae, but with rather lower values.
• 7.7. During pupal life, brain trehalase activity decreased markedly during the long period necessary to obtain diapause breakdown.
• 8.8. Wintering conditions allow a progressive increase of brain trehalase activity, which preceded the fall of trehalosemia.

     

Analysis of postembryonic development of locomotor activity rhythm by corpora allata implantation in the cricket gryllus bimaculatus

• 1.1. Male crickets Gryllus bimaculatus show a drastic change in circadian rhythm from nymphal diurnality to adult nocturnality, in association with an increase in activity level several days after the imaginai moult.
• 2.2. The corpora allata implantation into male 7th or 8th instar nymphs produced supernumerary instar nymphs in about 30% of the implanted animals, but did not affected the normal development in the remaining animals.
• 3.3. The majority of the supernumerary instar nymphs were diurnal and sexually inactive, although their internal reproductive organs appeared to be fully mature.
• 4.4. The supernumerary instar nymphs became nocturnal with an increase in activity level several days after the imaginai (9th) moult.
• 5.5. The roles of the nervous system in the regulation of the rhythm reversal are discussed.

     

Correlation of acid phosphatase but not alkaline phosphatase activity with myelination in the developing mouse brain

• 1.1. Neonatal mice received subcutaneous injections of buffer, thiourea (TU) or propylthiouracil (PTU).
• 2.2. The PTU-treated mice were sacrificed on postnatal day 14 (P14) and the TU-treated mice on P28.
• 3.3. Brain weights of the TU- and PTU-treated mice were not significantly different from the controls.
• 4.4. Acid but not alkaline phosphatase activity in the braistem decreased after TU and PTU treatment.
• 5.5. Myelination as indicated by intensity of luxol fast blue staining was weaker in drug-treated animals.
• 6.6. The level of myelin marker enzyme, 2′,3′-cyclic nucleotide 3′-phosphohydrolase, was lower in the brainstem of PTU-treated animals.
• 7.7. The results suggest a correlation between acid phosphatase but not alkaline phosphatase activity with myelination in the developing mouse brain.

     

Light-induced transient increase of the activity of topoisomerase I in plasmodia of Physarum polycephalum

• 1.1. Activity of topoisomerase I and incorporation of [³H]uridine and [¹⁴C]thymidine were monitored during light-induced sporulation of the slime mold Physarum polycephalun.
• 2.2. A 4-fold transient increase of topoisomerase I activity but not of [³H]uridine or [¹⁴C]thymidine incorporation was observed after 42 hr of illumination with 6 hr impulses.
• 3.3. The activity of topoisomerase I did not increase in the absence of light impulses. However, ca 5-fold increase of the activity was observed in dark when 100 μ M dibutyryl-cAMP was administered 12 hr before harvesting of plasmodia.
• 4.4. Fluorodeoxyuridine and cycloheximide administered 36 hr after starting of the illumination cancelled the increase of the activity of topoisomerase I.
• 5.5. After 7 days of the illumination, when fruiting bodies appeared, the activity of topoisomerase I dropped to about 15% of the initial value.

     

Some properties of ATPase activity in the intact cells of yeast Saccharomycopsis fibuligera

• 1.1. The properties of ATPase activity were studied with the cells at the early stationary phase of Saccharomycopsis fibuligera.
• 2.2. Optimal pH for the activity was approximately 7.
• 3.3. The activity was stimulated by Mg²⁺.
• 4.4. The activity was inhibited by NaF, DCCD, oligomycin, NaN₃, NaVO₃, or PCMB but not inhibited by ouabain.

     

Cross-correlation analysis of cerebrobuccal connective activity during Aplysia feeding behaviour

• 1.1. Two “en passant” electrodes were implanted around the cerebrobuecal connective (CBC) of Aplysia and used to record the activity, in the unrestrained animal, under three behavioural conditions; (a) absence of feeding behaviour, (b) appetitive feeding behaviour and (c) consummatory feeding behaviour.
• 2.2. The two simultaneous recordings were subjected to cross-correlation analysis, to subdivide spikes on the basis of their direction and speed of propagation.
• 3.3. There was virtually no CBC activity in the absence of food and feeding behaviour.
• 4.4. During appetitive feeding the metacerebral giant cell (MCC) was active and traffic was heaviest in the cerebral-to-buccal direction.
• 5.5. During consummatory feeding, traffic was also sustained in the buccal-to-cerebral direction; there was a reduction in the activity of the MCC, and a peak in the activity travelling to the cerebral ganglia, in the region of higher conduction velocity, was especially pronounced.
• 6.6. Further analysis showed this peak to have its largest amplitude during the actual ingestion of food and to be the result of the firing of several different units.
• 7.7. CBC traffic in both directions was also activated in one case of “spontaneous” biting.

     

Phosphatase activity in the hepatopancreas of Helix aspersa

• 1.1. Phosphatase acid (PhA) activity in the digestive gland (hepatopancreas) of the common garden snail Helix aspersa has been investigated using cytochemical methods.
• 2.2. All the cells composing this gland show PhA activity, the distribution pattern differing according to the cell type.
• 3.3. The digestive cells show the most widely distributed reaction product (brush border, phagolysosomes, multivesicular bodies and autophagic vacuoles).
• 4.4. In the excretory cells this activity appears in large sacs, while in the calcium cells the reaction product is abundant in the calcium granules.
• 5.5. Cellular digestion processes performed by each of these cell types is discussed together with their role in the detoxification of heavy elements derived from the environment.

     

Activation of neutrophils NADPH oxidase by PMA: Cytosol activity is translocated in phorbol-primed neutrophils

• 1.1. Translocation of cytosol activity in phorbol-primed neutrophils was studied.
• 2.2. Prior exposure of PMA or FMLP could potentiate the oxidative response by subsequent heterogeneous stimulus, FMLP or PMA.
• 3.3. In FMLP-primed neutrophils, the cytosol had almost the same activity as resting one and cytosol activity was not eluted from the membrane.
• 4.4. In PMA-primed neutrophils, however, the cytosol had less activity and cytosol activity was correspondingly eluted from the membrane.
• 5.5. These observations suggested that cytosol activity was translocated in PMA-primed cells.

     

Characterization of the Melanoplus sanguinipes hemolymph after infection with Beauveria bassiana or wounding

• 1.1. The phenoloxidase activity, protein and carbohydrate levels were studied for 24 hr in the hemolymph of the migratory grasshopper, Melanoplus sanguinipes after artificial wounding of the insect cuticle or the injection of Beauveria bassiana conidia.
• 2.2. Injection or wounding induced a primary response and phenoloxidase activity was found to increase within 10–60 min. The values for phenoloxidase activity in viable B. bassiana-injected insects exhibited a secondary response, i.e., an increase 24 hr after injection.
• 3.3. In wounded insects and those injected with inactivated conidia, the phenoloxidase activity receded after the initial increase and remained at low levels.
• 4.4. Protein concentrations in the hemolymph increased immediately after infection and wounding and returned to basal levels during the course of the experiment.
• 5.5. Injection of viable B. bassiana resulted in a gradual increase in the protein concentrations between 12 and 24 hr.
• 6.6. There was no apparent change in the carbohydrate levels in either B. bassiana-infected or wounded insects.
• 7.7. These results are discussed in relation to their possible role(s) and interrelationships in the immune response to infection or wounding. Furthermore, we suggest that a “factor” is released after mechanical injury of the integument.

     

Initial characterization of human thymocyte sialidase activity: Evidence that this enzymatic system is not altered during the course of T-cell maturation

• 1.1. The sialidase activity of human thymocyte was examined by a fluorogenic assay.
• 2.2. These studies revealed that human thymocyte sialidase activity is essentially acid-active and membrane-bound since 59.6% and 33% of the total activity was recovered in the lysosome-enriched and microsomal fractions, respectively.
• 3.3. A weak activity was also detected in the cytosolic fraction.
• 4.4. However, the acidic optimum pH of this soluble sialidase was at variance with the general concept of mammalian soluble sialidases which are known to be optimally active at more neutral pH.
• 5.5. This acidic soluble sialidase seems to be a general characteristic of the human T-cell lineage since examination of mature circulating T-cells revealed that they contain a soluble sialidase activity similar to that observed in thymocytes.
• 6.6. Analysis of mature and immature thymocyte subpopulation obtained by differential PNA agglutination indicated that this enzymatic system was not altered during the course of thymic maturation.
• 7.7. These results suggest that unlike in T-cell activation where changes in the level of sialidase activity were shown to influence the extent of cell surface sialylation and thereby the cell physiology, this enzymatic system seems not to be involved in the fluctuation of cell surface sialic acid content observed during thymic maturation.

     

Carbonic anhydrase activity in blood of early sheep fetuses

• 1.1. The level of carbonic anhydrase activity in the red cells was measured in sheep fetuses at different times after conception: 39, 56, 77, 90 and 140 days, the last being close to full term. Measurements were also made on blood from four of the mothers.
• 2.2. There was a low level of the enzyme present in the 39 day fetuses (0.037 enzyme units (E.U.)/100 μg Hb) and its increase up to 90 days of gestation (0.19 E.U./100 μg Hb) had a form approximating exponential.
• 3.3. The earliest levels were only 11% of the full term levels and only 4% of the adult levels previously reported.
• 4.4. Even the earliest samples were of blood that was fetal rather than embryonic but these results are the earliest carbonic anhydrase activities reported in this mammal.

     

Phenoloxidase activity of acridid grasshoppers from the subfamilies melanoplinae and oedipodinae

• 1.1. Phenoloxidase activity and wound melanization was studied in five species of grasshoppers representing the subfamilies Melanoplinae and Oedipodinae.
• 2.2. Most of the phenoloxidase activity was detected in the plasma fraction of grasshopper whole-body homogenates and supernatant fractions of the hemolymph. The species representing the Oedipodinae had 20–50% higher percentage of the total phenoloxidase activity associated with particulate matter from a whole-body homogenate when compared to the Melanoplinae.
• 3.3. Phenoloxidase activity could not be detected in sclerotized cuticle of adult grasshoppers.
• 4.4. The phenoloxidase existed as a zymogen which could be activated by chymotrypsin and inhibited by KCN and NaCN while EDTA showed no effect. It had optimum activity at 37°C and pH 7.3.
• 5.5. These findings are discussed in relation to wound repair and immune responses to infection in grasshopper species.

     

In vivo effect of Berenil on rat liver polyamine metabolism

• 1.1. Berenil, administered to rats in vivo, promoted a decrease in liver SAMDC activity, but an increase in ODC and SAT activity.
• 2.2. Its effect on ODC was completely prevented by cycloheximide, that on SAT only partially.
• 3.3. Berenil had no effect on ODC activity in adrenalectomized rats. Adrenergic antagonists counteracted the effect of Berenil on ODC activity.
• 4.4. Polyamine content was increased. The maximum modification was observed for putrescine and N¹-acetylspermidine.

     

The haemocytes and the activities of leucine aminopeptidase and alkaline phosphatase during development of Ceratitis capitata: Specific secretion of a leucine aminopeptidase isozyme

• 1.1. The types of haemocytes during larval development were studied.
• 2.2. The developmental profile of leucine aminopeptidase and alkaline phosphatase was studied. The maximum LAP activity was found to be in early larval development, while the maximum alkaline phosphatase during the white pupal stage.
• 3.3. These activities were compared with those determined in cell-free haemolymph.
• 4.4. Both hydrolytic enzymes have been found histochemically in the prohaemocytes and in the plasmatocytes.
• 5.5. In cultured haemocytes experiments it was found that 64% of the total LAP activity was secreted into the incubation medium, while electrophoretic analysis of released LAP activity demonstrated that only LAP A isozyme was secreted.
• 6.6. Based on the above results we suggest that both hydrolytic enzymes are functionally important throughout larval development.

     

Role of the visceral nerve in heart rate variations during different behavioral patterns in Megalobulimus sanctipauli (mollusca,gastropoda, pulmonata)

• 1.1. The role of the visceral nerve in mediating the changes in heart rate associated with different behavioral patterns was investigated in Megalobulimus sanctipauli.
• 2.2. The results of acute and chronic denervation experiments indicate that the visceral nerve has no excitatory or inhibitory tonic action on the heart of snails retracted into the shell, nor does it account for the increase in heart rate associated with the locomotion and feeding behaviors.
• 3.3. These changes in heart rate are, probably, indirect effects of increased activity such as an increase in venous return.
• 4.4. The visceral nerve is responsible for approximately 3/4 of the increase in heart rate associated with the first minute of extrusion.
• 5.5. The small increase in heart rate observed in denervated animals is probably caused by an increase in venous return generated by muscle activity that forces the head and food out of the shell.

     

Temperature acclimation in respiratory and cytochrome c oxidase activity in common carp (Cyprinus carpio)

• 1.1. Common carp (Cyprinus carpio) exposed to experimental temperatures of 12, 18, 24, 30 or 36°C for a 4-week period were used to investigate the effect of temperature acclimation on the frequency of opercular movement (FOM), growth and cytochrome c oxidase (CCO) activity in heart, liver and muscle.
• 2.2. An exponential relationship between FOM and temperature after the first week (10₁₀ =1.76) disappeared after the second week.
• 3.3. The initially high FOM at temperatures of 30 or 36°C and the low FOM at 18 or 12°C changed over 4 weeks to approach the FOM of fish at 24°C.
• 4.4. This change in the relationship of FOM to temperature from highly dependent to independent appeared to be thermal compensation.
• 5.5. Heart and liver CCO activities were significantly affected by temperature, with the lowest activity at the approximate optimum temperature for growth, 24°C.
• 6.6. Highest CCO activities for heart and liver occurred at both the highest and lowest temperatures.
• 7.7. Among the three tissues, heart CCO activity was generally the highest and most affected by acclimation temperature.
• 8.8. Muscle tissue had the lowest CCO activity and was unaffected by temperature.
• 9.9. The high CCO activity at a cold acclimation of temperature 12°C was probably due to thermal compensation and the high activity at 36°C may have been a result of thermal stress.

     

Monoclonal antibodies neutralizing the haemolytic activity of box jellyfish (Chironex fleckeri) tentacle extracts

• 1.1. Three monoclonal antibodies have been produced which neutralize in vitro the haemolytic activity present in tentacle extracts of the box jellyfish (Chironex fleckeri).
• 2.2. Two of these monoclonal antibodies bound specifically to a component of relative molecular mass 50,000 in tentacle extract on Western blots.
• 3.3. This binding only occurred when the extracts were electrophoresed under non-reducing conditions.
• 4.4. The third monoclonal antibody did not display binding to Western blots of tentacle extract under any of our experimental conditions.

     

Regulation of spermidine transport in l1210 cells

• 1.1. 1 mM 2-amino isobutyric add (AIB), glutamine or asparagine when preincubated for 3 hr with L1210 cells promoted a marked increase in the rate of spermidine uptake.
• 2.2. Cycloheximide also increased the transport rate and completely prevented the increase due to AIB.
• 3.3. Trifluoperazine and iso-H7 inhibited the uptake of spermidine, much less the uptake of AIB.
• 4.4. Adenosine promoted an increase in the uptake of AIB, a decrease in that of spermidine.
• 5.5. Hypotonic stress also increased the rate of spermidine transport. This modification was only partially prevented by cycloheximide.
• 6.6. Okadaic arid had no effect on this increase, whereas it prevented the increase of ODC activity.

     

Some properties of glucose uptake activity during early ascosporulation in Saccharomyces cerevisiae

• 1.1. The influence of heat or chemical treatment on the glucose uptake activity in vegetative cells and sporulating cells (3 h after transfer to sporulation medium) were examined in Saccharomyces cerevisiae.
• 2.2. Both glucose uptake activities had a similar stability in heat or NaOH treatments. v3. The activity of the sporulating cells was more stable in HCl treatment than that of the vegetative cells.
• 3.4. The activity of the sporulating cells was much more stable to desoxycholate treatment than that of the vegetative cells.