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.

     

Glucosyl and galactosyl transferase activities of diabetic (db/db) and obese (ob/ob) mice kidneys

• 1.1. Glucosyl and galactosyl activities were determined in kidney cortex tissue prepared from two strains of mice, genetically diabetic and obese mice.
• 2.2. These activities were measured as a function of ageing between 6 weeks and 13 months.
• 3.3. For both strains glucosyl transferase activity was shown to increase with respect to ageing whereas galactosyl transferase activity decreased at the same time.
• 4.4. These changes of enzymatic activities would suggest that a smaller increase of hydroxylysine-linked glycans than expected was observed under these pathological conditions.

     

Distribution of opine dehydrogenases and lactate dehydrogenase activities in marine animals

• 1.1. Opine dehydrogenases (OpDHs) and lactate dehydrogenase (LDH) activities were determined in various marine animals. OpDHs were detected in six marine invertebrate phyla; Porifera, Coelenterata, Annelida, Mollusca, Arthropoda and Echinodermata in phylogenic sequence.
• 2.2. Among several OpDHs, tauropine dehydrogenase (TaDH) occurred widely in marine invertebrates, from Porifera to Echinodermata.
• 3.3. With a few exceptions, total OpDHs activities exceeded that of LDH activity in the marine invertebrates investigated.
• 4.4. With respect to anaerobic glycolysis, OpDHs are indicated to play an important role in phylogenically lower invertebrates, whereas LDH is more important in higher animals.

     

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.

     

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.

     

Activities of hexokinase,phosphofructokinase and pyruvate kinase in the body wall,pyloric caeca and tube feet of Asterias vulgaris: Evidence of body wall as a major source of glycolytic activity

• 1.1. The activities of hexokinase (HK) and pyruvate kinase (PK) were significantly higher than the activity of phosphofructokinase (PFK) in the body wall, pyloric caeca and tube feet.
• 2.2. When expressed as a function of wet weight, the specific activity of HK was highest in the pyloric caeca. When expressed as a function of cytosolic protein, the specific activity of HK was highest in the body wall.
• 3.3. Specific activities PFK and PK, expressed as functions of cytosolic protein, were highest in the tube feet. These enzyme activities should reflect the high energetic requirements of the tube feet.
• 4.4. Highest total activity of PFK was found in the body wall. These results support the conclusion that the body wall is a metabolically active organ and that the energetic requirement of the body wall is a significant component of the energetic requirements of the organism.

     

Glycolytic enzymes of fowl and turkey spermatozoa

• 1.1. It was confirmed that, under anaerobic conditions, fowl spermatozoa formed lactate from glucose thirteen times faster than turkey spermatozoa.
• 2.2. The profiles of glycolytic enzyme activities were similar for spermatozoa from both species; however fowl spermatozoal activities were generally 2- to 4-fold higher.
• 3.3. Exceptions were glycerophosphate mutase and lactate dehydrogenase activities which were respectively 9.5 and 41 times greater in fowl spermatozoa.
• 4.4. In both species, spermatozoal glyceraldehyde-3-phosphate dehydrogenase had the lowest activity of the glycolytic enzymes.

     

Developmental changes of carbonic anhydrase activity of parotid gland and stomach of goat

• 1.1. Carbonic anhydrase activities in the various tissues of ruminants and non-ruminants were compared.
• 2.2. The highest activity was found in the parotid gland of ruminants such as bovine and goat. However the activity in the kidney was not significantly different between the ruminants and non-ruminants.
• 3.3. The effect of development on the carbonic anhydrase activity was studied. The activities in both the parotid gland and kidney of the goat were found to increase with age whereas the activities of the pancreas, liver and submaxillary gland did not change significantly.
• 4.4. The activities in the abomasum of the goat also increased with age however the other stomachs did not vary prominantly.

     

Effects of high dietary methionine on activities of selected enzymes in the liver of kittens (felis domesticus)

• 1.1. Growing male kittens were fed an 18% casein diet supplemented with 2, 3, or 4% l-methionine (MET) for 6 weeks.
• 2.2. Free MET concentration in liver increased 30-fold and cystathionine two- to three-fold; the activity of adenosyl-MET transferase and cystathionase also increased but remained lower than previously found in rats.
• 3.3. Taurine concentration in liver decreased in cats fed excess MET and appeared to depend on taurine intake.
• 4.4. Alanine aminotransferase activity was high in all groups while serine dehydratase activity was very low.
• 5.5. Pyruvate kinase and malic enzyme activities which are normally low in cat liver increased after excess MET. Also, glucose 6-phosphate and 6-phosphogluconate dehydrogenases increased.
• 6.6. Cat liver metabolism showed limited adaptation to an excess dietary intake of methionine compared to that found in rats.

     

Mixed function oxidase activity in the harbour seal (Phoca vitulina) from sable is., N.S.

• 1.1. One adult male, eight pups (including two full term foetuses) and nine adult female harbour seals (Phoca vitulina) were analysed for indices of mixed function oxidase (MFO) activity.
• 2.2. MFO activity was present in liver samples, but was at or below detection limits in samples of kidney, lung and pancreas.
• 3.3. Hepatic ethoxyresorufin O-de-ethylase and benzo[a]pyrene hydroxylase activities were similar to those reported in other seals and in other mammals.
• 4.4. Cytochromes P-450 and b₅ concentrations were slightly lower than those observed in other mammals.
• 5.5. MFO activities in newborn pups and foetuses were significantly lower than those in adult females.
• 6.6. No qualitative differences in cytochrome P-450 isozyme distribution between foetal and adult samples could be discerned by electrophoresis.

     

Changes in composition and proteolytic enzyme activities of artemia during early development

• 1.1. The proximate composition, total and free amino acids, and proteases of Artemia nauplii were determined during early development.
• 2.2. Moisture increased from 71.0% to 80.8%, crude protein decreased from 13.2% to 8.8%, crude fat and ash varied slightly.
• 3.3. The total amino acids decreased. Free amino acids changed in three patterns.
• 4.4. Trypsin, chymotrypsin, carboxypeptidase A, B and cathepsin B and C increased in activity. The activity of trypsin was lower, while cathepsin B and C were the highest.
• 5.5. The protease activities were maximal at pH 7.5 and 8.0, and at 45°C on casein.
• 6.6. The optimal pH for carboxypeptidase A was 4.0, for carboxypeptidase B was 4.5, for trypsin and chymotrypsin were 7.0–7.5. The protease(s) active at pH 9.0–9.5 were to be determined.

     

Ontogeny of type I and type III deiodinase activities in embryonic and posthatch chicks: Relationship with changes in plasma triiodothyronine and growth hormone levels

• 1.1. The ontogeny of type I and type III deiodinase activities was studied in embryonic and posthatch chicks.
• 2.2. Hepatic type I activity showed a 3-fold increase up to the period of pipping and hatching and decreased slowly thereafter.
• 3.3. Hepatic type III activity increased by 3-fold from E14 to E17 and decreased more than 10-fold from E17 to CO. Posthatch levels were very low.
• 4.4. Type I activity in the kidney decreased slowly after hatching while type III activity was very low over the whole period studied.
• 5.5. Developmental changes during the late embryonic period suggest a causal relationship between the increase in plasma GH and T₃ levels and the decrease in hepatic type III activity.

     

Acetylcholinesterase in Apis mellifera head during post-embryonic development. Existence of a glycoinositol-anchored membrane form at eary pupal stages

• 1.1. Properties of acetylcholinesterase (AChE, EC 3.1.1.7) from Apis mellifera head were studied during pupal development and at the adult stage.
• 2.2. During post-embryonic development, tissue and specific activities were closely related and increased to reach a maximum value at emergence and at last pupal stage, respectively.
• 3.3. In adults, AChE activity was weaker in foragers than in emerging bees.
• 4.4. The membrane form occurred in adult bees as well as in pupae whereas the soluble enzyme only appeared from Pd pupal stage.
• 5.5. The proportion of soluble and membrane forms fluctuated during late development but, in all cases, the percentage of the soluble form remained less than 10% of total AChE activity.
• 6.6. At all post-embryonic stages, the membrane form was sensitive to the action of phosphatidylinositol-specific phospholipase C (PI-PLC) and was converted into a hydrophilic enzyme.
• 7.7. In adult bees, the sensitivity to PI-PLC depended on the season. In summer, about 60% of the membrane activity could be solubilized by PI-PLC vs only 5% in winter.
• 8.8. The sensitivity of AChE to pirimicarb varied with the developmental stage.
• 9.9. In foraging bees, AChE was more susceptible to pirimicarb than in emerging bees. This difference of sensitivity to carbamate was abolished after removal of the membrane anchor either by mild trypsin digestion of PI-PLC treatment.

     

A study on the rna polymerase activities in bovine thyroid nuclei isolated in isotonic sucrose,hypertonic sucrose or in anhydrous glycerol media: Influence of the isolation procedure on the electrophoretic pattern of acid soluble nuclear proteins

• 1.1. After differential pelleting of bovine thyroid bound RNA polymerase II was the more enriched enzyme activity in the nuclear fraction, and coincided best with the DNA profile.
• 2.2. The RNA polymerase I + III activity was compared in nuclear fractions isolated either in 0.25 M sucrose (wet tissue) or in anhydrous glycerol (lyophilized tissue) or in 2.4 M sucrose (lyophilized tissue).
• 3.3. Although the nuclei were more resistant to the isolation porcedure in glycerol, more proteins were extracted by that procedure than during the isolation in 2.4 M sucrose.
• 4.4. With the 2.4 M sucrose method a twofold enrichment of RNA polymerase I + III activity in respect to DNA occurred in the nuclei pointing to an exclusive localization of these activities within the nucleus.
• 5.5. Using the same isolation procedure the different classes of histones were better resolved upon polyacrylamide gelelectrophoresis.

     

Acid and alkaline phosphomonoesterase activities in snake venoms

• 1.1. Acid and alkaline phosphatase activities of eight different snake venoms were determined quantitatively by using synthetic substrates, o-carboxyphenylphosphate and p-nitrophenylphosphate respectively.
• 2.2. It was found that most of Elapidae venoms investigated had both acid and alkaline phosphatase activities.
• 3.3. Three Crotalidae venoms investigated did not show any alkaline phosphatase activity.
• 4.4. The strength of venom acid phosphatase activity is as follows: Agkistroden acutus > Naja haje > Naja naja samarensis > Naja naja atra > Naja melanoleuca.
• 5.5. The strength of venom alkaline phosphatase activity by using p-nitrophenylphosphate is in the order of Naja hannah > Naja haje > Naja naja samarensis > Naja naja atra > Naja melanoleuca.When o-carboxyphenylphosphate was used as a substrate, the order of enzyme activity is Naja hannah > Naja haje > Naja naja samarensis > Naja melanoleuca > Naja naja atra.
• 6.6. Acid phosphatase activity of all the Elapidae venoms was inhibited completely by fluoride. The alkaline phosphatase activity of Elapidae venoms was not inhibited by fluoride either using p-nitrophenylphosphate or o-carboxyphenylphosphate.
• 7.7. The acid phosphatase of all the Elapidae venoms was not inhibited by zinc ion. However, most of the venom alkaline phosphatases were inhibited by zinc ion.
• 8.8. Ethylenediaminetetraacetic acid (EDTA) had inhibitory action on venom phosphatase activity. However, tris-(hydroxymethyl)-aminoethane had a counter effect on the inhibitory action of EDTA.
• 9.9. Optimum pH studies of the snake venom phosphatases showed that the acid phosphatases of the snake venoms had their highest activity in the range of pH 4–5. The alkaline phosphatases of the snake venoms had their optimum pH at 9.
• 10.10. Comparable experiments were also conducted by using chicken intestine alkaline phosphatase and wheat germ acid phosphatase.

     

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.

     

Lipoxygenase and other enzymes of arachidonic acid metabolism in the brain of chicks affected by nutritional encephalomalacia

• 1.1. Prostaglandin endoperoxide synthetase (PES) and lipoxygenase (Lox) activities were compared in the cerebella and cerebra of vitamin E-sufficient young chicks and in chicks in which nutritional encephalomalacia (NE) was induced by a diet deficient in vitamin E.
• 2.2. Eicosanoid production patterns were qualitatively similar in the brains of both groups of chicks, but prostaglandin production was 50–60% less in cerebella of ataxic chicks, compared to control cerebella, while the opposite trend was observed in the cerebellar Lox pathway, as measured by radioimmunoassay of 15-HETE.
• 3.3. Cerebellar phospholipase A, activity was twice that of the cerebrum but was not affected by NE.
• 4.4. Purification of Lox activity from the cerebellar homogenates produced a lower yield and enrichment when the starting material was taken from ataxic chicks, compared to the controls.
• 5.5. In addition there were qualitative differences in the purified fractions from both groups, as seen by pH optima and kinetics.
• 6.6. The results are consistent with the view that the cerebellum has less antioxidant protection than the cerebrum and that its higher phospholipase A₂ activity and greater propensity to oxygenate arachidonic acid via the Lox pathway at the expense of the PES pathway may render this region of the brain particularly vulnerable to oxidative damage in NE.

     

Enzymes of fructose metabolism in the intestinal mucosa of the rat (Rattus norvegicus). Localization along the small intestine; consequences of dietary fructose

• 1.1. The activities of all the eight enzymes of conversion of fructose to glucose, of all the three key enzymes of glycolysis and of the two dehydrogenases of pentose shunt were determined in proximal and distal mucosa of small intestine.
• 2.2. With the exception of hexokinase, all of these enzymes have an activity significantly higher in the proximal than distal mucosa.
• 3.3. The gradient along the intestine is particularly important for the three enzymes which are typical for fructose metabolism (ketohexokinase, triokinase and fructose-1-phosphate aldolase), for glucose-6-phosphatase and for phosphofructokinase.
• 4.4. The effects of fructose diet on the enzyme activities are compatible with the results, described in other papers, concerning the final products of metabolism.
• 5.5. The increase of fructose metabolism appears to result mainly from the stimulation of the activities of ketohexokinase and fructose-1-phosphate aldolase which control all the pathways of ketohexose utilization.
• 6.6. The activation of glucose-6-phosphatase, in comparison with the other enzymes which are involved in glucose-6-phosphate metabolism, explains the appearance of the ability to synthesize glucose with fructose as substrate. This enzyme is the only key enzyme of fructose to glucose conversion which responds to fructose feeding in distal mucosa.
• 7.7. The activities of hexokinase and phosphofructokinase are not increased by fructose feeding.
• 8.8. The activity of pyruvate kinase. the only key glycolytic enzyme which is necessarily implicated when fructose is the substrate, is stimulated but less than the typical enzymes of fructose metabolism.
• 9.9. But, because of its quantitative importance, the glycolytic pathway is responsible for the most part of the observed increase of fructose utilization.
• 10.10. The responses of pyruvate kinase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities to fructose feeding are similar in the two parts of small intestine.
• 11.11. The activities of ketohexokinase, triokinase and glucose-6-phosphate isomerase are stimulated only in the proximal small intestine mucosa.
• 12.12. The other enzyme activities which are stimulated in proximal segment are also increased in distal segment.
• 13.13. All segments of small bowel show adaptive changes to dietary manipulation but not necessarily for all their functions.
• 14.14. The gradient of enzyme activities from the proximal to the distal small intestine persists despite dietary modification, but the data do not determine that this gradient is intrinsic or that it is not intrinsic.

     

Changes in heart rate with growth and activity of white-tailed deer fawns (Odocoileus virginianus)

• 1.1. Heart rates of five unrestrained white-tailed deer fawns were monitored for 24 hr periods at intervals between birth and weaning at about 100 day of age (25 kg body weight).
• 2.2. Mean heart rates during lying-resting activity declined exponentially with body weight to about 54% of the neonatal rate.
• 3.3. Increases in the mean heart rate with spontaneous changes in activity from lying to lying-ruminating, standing, foraging, walking and running were related curvilinearly to body weight.
• 4.4. Heart rates for these same activities were higher when fawns were alarmed or excited.

     

Myofibril and sarcoplasmic reticulum changes during muscle development: Activity vs inactivity

• 1.1. The purpose of this study was to determine whether biochemical changes of skeletal muscle that occur as a result of exercise in young rats persist into adulthood.
• 2.2. Littermates (10 days old) were assigned to a 3, 6 and 12 week control or training group. In addition, a rest-exercise group (R-E) and exercise-rest (E-R) group were included.
• 3.3. The rest-exercise and exercise-rest rats were maintained for the 12 weeks with the first 6 weeks being either rest or exercise and the condition reversed during the last 6 weeks of the experiment.
• 4.4. Myofibril ATPase activity of rat plantaris increased from the 10d to 12 week animals (P < 0.05). As anticipated, training resulted in a lowered activity at 6 and 12 weeks compared to controls.
• 5.5. The Ca²⁺ uptake and Ca²⁺-ATPase activity of the sarcoplasmic reticulum followed a similar pattern.
• 6.6. With regard to the exercise-rest rats, the myofibril and SR ATPase activities at 12 weeks were comparable to the 12 weeks control rats.
• 7.7. The rest-exercise group approximated the 12 week training group with regard to myofibril and SR ATPase activities (P > 0.05).
• 8.8. The results suggest that the training adaptations that occur during development of skeletal muscle return to normal, when training ceases in the adult rat.
• 9.9. Furthermore, animals that started to train prior to puberty do not have a greater capacity to adapt than animals which initiated training during adulthood.