Effects of low temperatures on NAD-sorbitol dehydrogenase activity and morphogenesis in non-diapause eggs of the silkworm,Bombyx mori

• 1.1. The activity of NAD-sorbitol dehydrogenase (NAD-SDH; EC 1.1.1.14) and levels of sorbitol were examined in non-diapause eggs of the silkworm, Bombyx mori, exposed to temperatures of 20-0.5°C from 1 day after oviposition. The morphology of embryos in the cold-acclimated eggs and the hatching of eggs after transfer to 25°C were monitored.
• 2.2. Temperatures between 15 and 0.5°C retarded the development of NAD-SDH activity at a specific embryonic stage that was comparable to diapause, and sorbitol accumulated in the eggs.
• 3.3. With the appearance of NAD-SDH activity, sorbitol was converted into glycogen, just as it is in diapause eggs. The results indicate that NAD-SDH participates in the utilization of sorbitol rather than in its formation in non-diapause eggs.
• 4.4. Distinct effects of low temperatures on the morphological development of the embryos are also discussed.

     

Utilization of body stores in embryonated ova and larvae of two coregonid species (Coregonus lavaretus L. and C. albula L.)

• 1.1. Developing eggs of whitefish (Coregonus lavaretus L.) and vendace (Coregonus albula L.) were kept at 1–2°C and some eggs taken gradually up to 8°C to provoke mass hatching of embryos.
• 2.2. Wet weight, dry matter and the contents of lipid, protein and ash were measured in fish during the course of experiment.
• 3.3. Dry matter content decreased gradually in whitefish eggs from 15.64 to 11.95% during 1 month at 1–2°C, whereas vendace eggs showed only a slight decrease from 16.27 to 15.53%.
• 4.4. In both species protein content decreased but lipid increased when approaching the natural time of hatching.
• 5.5. During delayed hatching at low water temperatures protein contributes to catabolism, whereas lipid content decreased only in the later phase of the experiment.
• 6.6. Larvae starved for 10 days after hatching lost increasing amounts of dry matter (from 26.1 to 50.3% of body weight) and protein (from 18.7 to 45.9% of body weight) as they remained longer in cold water as embryos.
• 7.7. A correspondence was found between assessment of metabolic utilization of body stores based on chemical analysis of fish body and previous work on oxygen consumption and nitrogen excretion.

     

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.

     

Allopurinol and theophylline: Their effect on longevity,fertility and behavior of hornets kept under different light and crowding conditions

• 1.1. The present work deals with the effect of feeding hornets on moderate amounts of theophylline and allopurinol.
• 2.2. The median survival time of hornets fed on allopurinol was greater than that of hornets fed on theophylline, while that of a control group fed on sugar solution alone was between the two drug-fed groups.
• 3.3. The controlled-diet hornets, which were kept in the groups of 10, lived longer than hornets in groups of 20 or 40.
• 4.4. Those fed on theophylline usually did not eat proteins, niether did they build cells, lay eggs nor engage in any social activity. They behaved rather like queen hornets during the winter diapause.
• 5.5. Hornets fed on allopurinol built less cells and combs than did the controls. They were very aggressive, produced fewer eggs, attended less brood than did the controls and fed intensively on proteins (partly through cannibalism).

     

Effect of low rearing temperature on development of Galleria mellonella larvae and their sensitivity to juvenilizing treatment

• 1.1. The development of Gallena mellonella is strongly affected by a low temperature of 18°C (the last instar persists for more than one year, instead of about 9 days at 30°C). At 18°C the last instar Galleria mellonella larvae respond to juvenilizing treatment—chilling stress or juvenile hormone analogue—with a very low percentage or no supernumerary moults, respectively.
• 2.3. Experiments in which larvae subjected to such treatments were transferred from 18°C to 30°C and vice versa showed that for the realization of the larval programme after chilling stress application the higher (30°C) temperature is needed.
• 3.4. In last instar larvae reared at 18°C there coexist very high juvenile hormone titre and high juvenile hormone esterase activity.
• 4.5. This phenomenon which is found in both, chilled and unchilled larvae, is discussed.

     

Immunocytochemical localisation of vitellogenic and non-vitellogenic yolk proteins in the ovary of leptinotarsa decemlineata

• 1.1. Two vitellogenins and chromoprotein 2 are selectively accumulated by the oocyte and cannot be detected either in follicle cells or in the germarium.
• 2.2. At the start of their accumulation in terminal oocytes they are asymmetrically distributed.
• 3.3. Endocytosis of vitellogenin 1 starts somewhat later than the uptake of vitellogenin 2 and chromoprotein 2.
• 4.4. In follicle cells of young follicles, a protein (DLP), immunologically related to diapause protein 1, is highly concentrated.
• 5.5. During vitellogenesis DLP is sequestered by the oocytes.
• 6.6. The protein rich globules in terminal oocytes contain the vitellins as well as chromoprotein 2 and DLP.

     

The effects of cooling the egg on the respiratory movements of the hatching fowl,Gallus g. domesticus,with a note on vocalization

• 1.1. The ambient temperature of pipped eggs of the domestic fowl was reduced from 39 to 20°C for a period of 2 hr.
• 2.2. In the majority of embryos the amplitude of respiration more than doubled during the first hour, and in each embryo the frequency fell to a minimum value by the end of cooling.
• 3.3. When the eggs were rewarmed the respiratory frequency usually returned to normal within a period of 1 hr. Vocal activity was often stimulated and was accompanied by a marked increase in the amplitude of respiration.
• 4.4. These results are discussed in relation to the development of thermoregulation, and are compared with results obtained elsewhere in a similar study on the quail.

     

Some kinetic studies on immobilized uricase

• 1.1. Uricase was immobilized onto glutaraldehyde-activated nylon tube.
• 2.2. The activity of the immobilized uricase tube was assayed by a plug-flow method adopting the integrated form of Michaelis-Menten equation.
• 3.3. Up to about 60% activity of the soluble enzyme is retained when the enzyme is derivatized.
• 4.4. Effects of changing certain parameters in the assay system were also shown.
• 5.5. The immobilized uricase has an optium pH of about 9.0, and is quite stable at 37°C when stored in borate buffer pH 9.0 in the presence of NaCl and Triton × 100.

     

Lactate dehydrogenase of goldfish red and white muscle in relation to thermal accumulation

• 1.1. Activities of the red and white muscle LDH from 8°C-acclimated goldfish were about three times higher than those acclimated to 28°C.
• 2.2. Isozyme composition and some kinetic properties of the red muscle LDH differed from those of the white muscle enzyme.
• 3.3. The amount of red muscle as well as LDH activity tended to increase during cold acclimation.

     

γ-Glutamyltranspeptidase in echinoderm eggs and larvae: fertilization-dependent and developmentally-induced changes in specific activity

• 1.1. γ-Glutamyltranspeptidase is present in echinoderm eggs and larvae: in homogenates the level of activity is comparable to that of rat cerebral cortex.
• 2.2. In eggs of Lytechinus pictus, fertilization induces an early rapid and sustained (5 min–6 hr) 37% increase in the activity of γ-glutamyltranspeptidase in homogenate fractions.
• 3.3. Relative to these homogenate levels, the specific activity of γ-glutamyltranspeptidase are ≈60% lower in 40,000 g supernatant fractions and 2.7-fold higher in 40,000 g particulate fractions in both unfertilized and 15 min post-fertilized Lytechinus pictus eggs.
• 4.4. The subcellular distribution of γ-glutamyltranspeptidase is the same in both unfertilized and 15-min post-fertilized Lytechinus pictus eggs: 78% in 40,000 g particulate fractions, 22% in 40,000 g soluble fractions.
• 5.5. In both unfertilized and 15 min post-fertilized eggs of Lytechinus pictus the enzyme responds to heat (50 vs 37°C) by activation in a similar manner: 1.72- and 1.68-fold homogenates; 2.6- and 3.0-fold in supernatants; 1.97- and 1.90-fold in particulate fractions.
• 6.6. In homogenates of Pisaster ochraceous larvae, γ-glutamyltranspeptidase activity increases steadily during the course of larval development: relative to the low activity at day 5, activities exhibit an increase of 1.2-, 2.0-, 3.1- and 5.4-fold at days 10, 16, 22 and 28, respectively.

     

Dynamics of Hlo content in rat liver after partial hepatectomy

• 1.1. The changes in the lysine-rich histone subfraction hl₀ have been quantitatively studied in rat liver during the regeneration period after partial hepatectomy.
• 2.2. A gradual decrease in this protein was found early after operation with a minimal value around the time of maximal mitotic activity.
• 3.3. The reduction in the hl₀ content paralleled well the increasing number 0f cells in the cell cycle.

     

Lipoxygenase of the thermophilic bacteria thermoactinomyces vulgaris—properties and study on the active site

• 1.1. A lipoxygenase activity was purified from Thermoactinomyces vulgaris and some of its properties were characterized.
• 2.2. The enzyme showed a temperature activity range of 40–55°C with still significant activity over 60°C.
• 3.3. The pH of activity on linoleic acid had a broad range with an optimum at pH 6.0 and a weaker one at pH 11.0.
• 4.4. On arachidonic acid the pattern was narrow bell-shaped with an optimum at pH 6.5.
• 5.5. The purified lipoxygenase from Th. vulgaris showed an apparent K_m of 1 mM and V_max of 0.84 μmol diene/min/mg protein.
• 6.6. It was inhibited by the oxidation products, 9-HPOD and 13-HPOD.
• 7.7. A 160,000 Da molecular weight of the enzyme was determined by molecular filtration. Methionine, tyrosine, tryptophan and cysteine are apparently involved in its activity.

     

Evidence of an egg-laying factor in the prostatic secretions of Helix aspersa müller

• 1.1. A high percentage (53%) of isolated snails injected with prostate gland homogenates lay eggs.
• 2.2. These egg masses consist of a few eggs which contain many nonviable oocytes.
• 3.3. Preliminary experiments suggest that an egg-laying factor may be present in prostatic secretions.
• 4.4. Snails bred in isolation from hatching, whether injected or not, occasionally lay viable eggs.
• 5.5. This observation shows that self-fertilization or parthenogenesis is, in fact, possible in Helix aspersa Müller.

     

Analysis of clotting defects in diseased lobsters—II. Immunochemical study of blood proteins

• 1.l. In gaffkemic lobsters kept at 15°C, the plasma coagulogen amount rapidly decreases and the gelation of hemolymph is prevented.
• 2.2. In animals kept at 10°C, the available plasma coagulogen amount is always normal even when coagulation appears impaired or prevented.
• 3.3. Extended clotting times as well as damaged coagulation cannot be correlated with coagulogen concentration.
• 4.4. The site of synthesis of this factor is discussed.

     

A comparison of aspartate transcarbamylase activity in juvenile pacific oysters (Crassostrea gigas) when fed various diets

• 1.1. The optimum pH for measurement of aspartate transcarbamylase activity in oyster tissue was determined to be 9.35 while the optimum temperature was 39.5°C.
• 2.2. Aspartate transcarbamylase activity varied significantly over short periods of time (hr) possibly due to fluctuations in the amount of food digested.
• 3.3. The composition of the oyster's diet also affected the levels of aspartate transcarbamylase activity in oyster tissues.
• 4.4. Those oysters fed an egg yolk-starch diet contained significantly lower aspartate transcarbamylase activity than oysters fed an egg yolk-starch-salmon oil diet or a casein-starch-salmon oil diet.
• 5.5. The aspartate transcarbamylase activities in oysters fed Phacedactylum tricornutum or a starch diet were not significantly different from the activities in oysters fed the egg yolk-starch diet.

     

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.

     

Cumene hydroperoxide-induced chemiluminescence in human erythrocytes: Effect of antioxidants and sulfhydryl compounds

• 1.1. The time-course of cumene hydroperoxide-induced changes in lipid peroxidation, protein sulfhydryl groups and chemiluminescence intensity was determined in human erythrocytes.
• 2.2. Increase in lipid peroxidation was maximal within 60 min of incubation and was paralleled by a decrease in protein sulfhydryl groups and an increase in chemiluminescence formation.
• 3.3. A standard assay system was established to investigate the protective effects of antioxidants and scavenger compounds on cumene hydroperoxide-induced chemiluminescence formation.
• 4.4. Chain-breaking antioxidants (i.e. butylated hydroxytoluene) and sulfhydryl compounds (i.e. dithiothreitol) were able to suppress chemiluminescence formation.
• 5.5. Our results suggested that secondary free radicals, as well as sulfhydryl groups of proteins are involved in cumene hydroperoxide-induced chemiluminescence formation.

     

Further studies on the phylogenetic distribution of pyruvate oxidoreductase activities

• 1.1. The phylogenetic distribution of lactate, octopine, alanopine and strombine dehydrogenase activities (respectively, LDH, ODH, ADH and SDH) was examined in over 60 species from seven phyla and from three continents.
• 2.2. The results confirm and extend previously published data. Consistencies of distribution are observed at the levels of phyla, class, order and family.
• 3.3. Major observations include prominent SDH in the Porifera; LDH only in the Polyplacophera, Nudibranchia and Myidae (Mollusca) and nereid worms (Polychaeta); ODH and SDH in the marine pulmonate Melampus bidentatus (Basommatophora); high ADH to SDH ratios in marine gastropods; high ODH in active molluscs; and apparent SDH in the barnacle Lepas anatifera.
• 4.4. The results are discussed in relation to theories of opine pathway evolution and the newly discovered tauropine and β-alanopine opine dehydrogenases.

     

Phospholipase A activity of culture supernatants from Streptococcus mutans strain 6715

• 1.1. Phospholipase A activity was found in the culture broth of growing cultures of Streptococcus mutans strain 6715.
• 2.2. The amount of enzyme activity was proportional to the cell density of the cultures.
• 3.3. The enzyme had a pH optimum of 7.0 and was inactivated at temperatures greater than 45°C.
• 4.4. The enzyme was Ca²⁺-dependent, since both EDTA and EGTA were inhibitory and Ca²⁺ was stimulatory.
• 5.5. Analysis of the fatty acid products resulting from the enzyme's action on 1-palmitoyl-2-oleoyl phosphatidylcholine indicated the enzyme to be a phospholipase A₁, (EC 3.1.1.32).

     

Characterization of NaK ATPase from the gills of the freshwater prawn Macrobrachium rosenbergii (de Man)

• 1.1. The specific activity of Na-K ATPase was determined from the microsomal preparation of gills dissected from adult Macrobrachium rosenbergii.
• 2.2. Maximal ATPase activity was achieved at a substrate concentration of 0.5 mM ATP.
• 3.3. Optimal enzyme activity was obtained at pH of 7.5.
• 4.4. The Arrhenius plot of Na-K ATPase activity revealed a marked discontinuity at 30°C. “Mg” ATPase activity did not exhibit a marked discontinuity.
• 5.5. The E_a for Na-K ATPase and “Mg” ATPase was 14.6 kCal/mole and 9.31 kCal/mole respectively. Q₁₀ values for Na-K ATPase was 2.34 and for “Mg” ATPase 1.65.
• 6.6. ATPase activity and gill homogenate protein concentration exhibited a linear relationship up to 130 μg protein/ml.
• 7.7. Na-K ATPase activity was inhibited by 10⁻³ M ouabain. It was equally inhibited by the removal of K⁺ from the reaction medium.