Renal response to hypoxia in carp,Cyprinus carpio: Changes in glomerular filtration rate,urine and blood properties and plasma catecholamines of carp exposed to hypoxic conditions

• 1.1. Changes in glomerular nitration rate (GFR), urine and blood properties and plasma catecholamines of carp were investigated during and following hypoxia.
• 2.2. GFR and urine flow decreased with increased urinary concentrations of bio-components, except protein, in the course of hypoxia.
• 3.3. Decreases in blood pH, and increases in haematocrit value and plasma K⁺, Ca²⁺, Mg²⁺, inorganic phosphate (P_i), ammonia, lactic acid and catecholamines (CAs) were observed as hypoxia progressed.
• 4.4. Increased GFR and urine flow, and higher values for urinary components, except protein, compared with those of the control were found in the initial post-stress stage.
• 5.5. The possible significance of increased plasma CAs in relation to changes in renal function in hypoxic carp is discussed.

     

Effects of membrane-perturbing drugs and noradrenalin on cAMP accumulation and red cell water content in carp (Cyprinus carpio) red cells

• 1.1. Carp red cells were treated with drugs that affect the cell membranes. The water content of the cells and the accumulation of cAMP in the cells were measured in normoxia and in hypoxia using non-stimulated and adrenergically stimulated cells.
• 2.2. WGA, DIDS + CCCP and A23187 increased the water content of nonstimulated normoxic cells.
• 3.3. In hypoxia ouabain and DIDS + CCCP increased the water content but cytochalasin B, NPM, DIDS, CCCP and A23187 + CA²⁺ abolished the hypoxia-induced swelling.
• 4.4. Any membrane perturbation induced some cAMP formation, Sophora and Anquilla lectins being most potent.
• 5.5. Also in adrenergically stimulated cells, membrane perturbation generally increased cAMP formation.
• 6.6. However, cAMP accumulation diminished in cells treated with cytochalasin B, CCCP and DIDS + CCCP.
• 7.7. The adrenergic swelling of carp red cells was reduced in normoxia by DIDS. NPM and CCCP increased the adrenergic swelling in normoxia to hypoxic level.
• 8.8. In hypoxia WGA and Anquilla lectin decreased the swelling.

     

Variations in response to environmental hypoxia of different colour forms of the shore crab,Carcinus maenas

• 1.1. The oxygen consumption of red and green Carcinus in normoxic and hypoxic sea water was determined, using an oxygen electrode in a sealed respirometer.
• 2.2. The red crabs had significantly higher “excited” oxygen uptake rates and a lower ability to compensate for hypoxia than the green crabs.
• 3.3. Red Carcinus display an emersion response to declining oxygen at lower oxygen tensions than the green crabs.
• 4.4. Mortality of red crabs exposed to prolonged anoxia was much greater.
• 5.5. The relationship of these findings to the zonation of the two colour forms on the shore is discussed.

     

Effects of temperature and metabolic inhibitors on contraction of anterior byssus retractor muscle of Mytilus

• 1.1. Anterior byssus retractor muscle of Mytilus (ABRM) was stimulated to contract by ACh (acetylcholine) and effects of temperature (5–30°C), FDNB (1-fluoro 2,4 dinitro-benzene) and IAA (iodoacetic acid) on tension response were examined.
• 2.2. Isometric tension was highest at the temperature range of 10–20°C and decreased at higher and lower temperature than that range.
• 3.3. The rate of tension decay after washing of ACh was accelerated by the increase of temperature.
• 4.4. Tension redevelopment after release of 1 % during contraction was much smaller at 5°C than at 20°C.
• 5.5. Tension development by ACh and the rate of tension decay after washing of ACh were remarkably decreased by the treatment of FDNB or IAA.
• 6.6. The above results were discussed from the viewpoint that energy metabolism might be related to catch.

     

The influences of individual variations in metabolic rate and tidal conditions on the response to hypoxia in Carcinus maenas (L.)

• 1.1. The oxygen consumption of crabs in normoxic and hypoxic (50% O₂) seawater was measured directly after collection.
• 2.2. The influences of size and lunar cycles were removed by scaling the data.
• 3.3. Strong negative correlations between low individual levels of O₂ consumption and the ability to compensate for hypoxia were apparent in Wicklow (subtidal) crabs.
• 4.4. Compensation for hypoxia was much greater on the flood tide than on the ebb.
• 5.5. Crabs from Roscoff (intertidal) had lower levels of compensation than those from Wicklow.
• 6.6. Size, sex and condition had no apparent effect upon these relationships.
• 7.7. Crabs acclimated to laboratory conditions have not shown this tidal variation in compensation for hypoxia.

     

A relationship between circulating natural glucocorticoids and the mechanical responses of the heart in atricial and precocial rodents

• 1.1. A comparison was made of the mechanical performance of heart muscle from mouse, an atricial mammal, with corticosterone as glucocorticoid and spiny mouse (Acomys cahirinus), a precocial mammal, with cortisol as glucocorticoid.
• 2.2. Force-frequency responses were negative in mouse and positive in spiny mouse.
• 3.3. During recovery, there was a gradual increase and an overshoot in the mouse, while in the spiny mouse there was an initial enhanced response, diminishing gradually with time.
• 4.4. High calcium concentration inhibited contractile tension in mouse heart, while it was positively inotropic in spiny mouse heart. Changes in the concentration of calcium did not change the patterns of force-frequency response.
• 5.5. Lowering the experimental temperature increased the time course and amplitude of the tension curve. However, various parameters exhibited different temperature sensitivity.
• 6.6. There was a significant difference in the levels of circulating cortisol between male and female spiny mice.
• 7.7. It is proposed that the differences in the mechanical responses of mouse and spiny mouse hearts may be explained in terms of the effects of the specific glucocorticoid hormone on the development of the sodium-calcium exchanger.

     

Localization of the glucocorticoid receptor in rat liver cells: Evidence for plasma membrane bound receptor

• 1.1. The cytoplasmic glucocorticoid receptor of rat liver cells is in part recovered in the plasma membrane fraction.
• 2.2. After in vivo administration of [³H]dexamethasone, 0.35% of the radioactivity recovered is bound on plasma membranes.
• 3.3. Dexamethasone also binds in vitro specifically to plasma membranes. Expressed as fmol/mg protein, binding of dexamethasone to plasma membranes is comparable to binding to the soluble cytoplasmic fraction (cytosol).
• 4.4. Using polyclonal antibody to the glucocorticoid receptor and the indirect immunofluorescence technic, an intense decoration of the plasma membranes is observed, denoting a high concentration of glucocorticoid receptor on plasma membranes.
• 5.5. The localization of the receptor on plasma membranes could be of potential importance for its interaction with agents (mitogens, growth factors) initially acting on the cell membrane, regulating subsequent cell proliferation and growth at the level of the cell nucleus.

     

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.

     

Laboratory studies on the oxygen consumption of the marine teleost,Lichia amia (Linnaeus, 1758)

• 1.1. The oxygen consumption of the marine teleost, Lichia amia was investigated under controlled laboratory conditions.
• 2.2. The routine oxygen consumption showed a strong circadian rhythm with the fish being mainly active during the light period.
• 3.3. The specific mass exponent (dimension: μg O₂/g/hr) is temperature independent and ranges from 0.27–0.29.
• 4.4. Starving the fish results in a mean decrease in active, routine and standard oxygen consumption of 21%, 24% and 20%, respectively.
• 5.5. Feecling led to an increase in the oxygen consumption of the teleosts, with the mean metabolic rate over the 24 hr that followed, being 58% and 50% higher for fish that had been starved for 162hr and 40 hr, respectively.
• 6.6. Apparent SDA showed some variation and ranged from 6.0 to 35.5%.
• 7.7. The results obtained are generally in agreement with those recorded for other teleosts.

     

Variations of respiratory rate of Tisbe holothuriae humes (copepoda,harpacticoida) in relation to temperature,salinity and food type

• 1.1. The influence of temperature (14,19, 24°C), salinity (26,32, 38,44%.) and food type (artificial diets: Fryfood, Mytilus, Soya, Yeast, Spirulina) on the respiratory rate of Tisbe holothuriae has been studied.
• 2.2. Oxygen consumption decreased with decreasing temperature, but with a greater rate at supra- or subnormal salinities.
• 3.3. Multiple-regression analysis showed the quadratic effect of temperature and the linear effect of salinity to be the more important factors affecting respiration.
• 4.4. The food type also seems to exert an important effect on oxygen consumption.
• 5.5. A significant lowering of respiration was observed for all food tested when the animals were starved.

     

Adaptative features of amazon fishes: Hemoglobins,hematology, intraerythrocytic phosphates and whole blood Bohr effect of Pterygoplichthys multiradiatus (Siluriformes)

• 1.1. Hemoglobin, hematological parameters, intraerythrocytic phosphates and whole blood Bohr effect of Pterygoplichthys multiradiatus, from the Amazon river, were studied in three different conditions: in their natural environment, acclimated to normoxia and acclimated hypoxia conditions.
• 2.2. Nine anodal hemoglobin fractions were detected on starch gel electrophoresis. No qualitative differences in the Hb electrophoretic patterns were detected in the three studied groups.
• 3.3. Hematocrit, hemoglobin concentration, MCV, MCHC and MCH were different among studied conditions.
• 4.4. GTP was almost absent in the blood of animals in natural conditions and acclimated to hypoxia, but was present at a concentration similar to ATP in normoxic acclimated animals.
• 5.5. There is a tendency for higher Hb-O₂ affinity for hypoxic acclimated/acclimatized animals.

     

Measurements of oxygen consumption in Mytilus edulis during exposure to,and recovery from,high sublethal concentrations of formaldehyde,benzene and phenol

• 1.1. The rate of oxygen consumption has been monitored continuously in M. edulis during acute exposure to high sublethal concentrations of formaldehyde, phenol and benzene and subsequent recovery periods of 96 hr.
• 2.2. The results are discussed in relation to changes in the electrochemical potential difference of sodium, the content of ATP and the tissue concentration of strombine.
• 3.3. After exposure to benzene and phenol, an increase in the rate of oxygen consumption that could not be explained by oxygen debt from the exposure period was observed.
• 4.4. Depression of the rate of oxygen consumption after exposure to formaldehyde may be explained by a reduced ability to extract oxygen from the water.
• 5.5. The pattern of oxygen consumption and behavioural responses, as well as the combined changes in the biochemical markers, were distinctly different in the three cases.

     

Variations in tissue reserves,plasma metabolites and pancreatic hormones during fasting in immature carp (Cyprinus carpio)

• 1.1. Immature carp were subjected to 2-month fasting periods. Mobilization of reserves in liver and muscle, and the energy contribution of each reserve were studied. Changes in plasma glucose, amino acids, insulin and glucagon levels were determined throughout the experiment.
• 2.2. No changes were observed in plasma glucose, insulin or glucagon at 19 days of fasting, but plasma amino acids increased. At 50 days of fasting, both plasma glucagon and amino acids increased, liver glycogen decreased and muscle proteolysis began.
• 3.3. Between 50 and 67 days of fasting, plasma glucose and insulin decreased significantly, while glucagon and amino acids continued to increase. Strong muscular proteolysis was observed while liver glycogen stabilized.
• 4.4. The contribution of each reserve in liver and muscle to energy production throughout fasting is considered.

     

Respiratory mechanisms and metabolic adaptations of an intertidal crab,Chasmagnathus granulata (Dana, 1851)

• 1.1. The ventilatory mechanism, gill area, sites of oxygen uptake, oxygen consumption and activity of a crab from south Brazil, Chasmagnathus granulata, were investigated.
• 2.2. The oxygen uptake seems to be restricted to the gill lamellae.
• 3.3. The gill area varies with the wet body weight, being relatively higher in smaller animals. There is not a significative reduction of the gill area in relation to species of the infralittoral zone.
• 4.4. C. granulata presents a mechanism for recirculating the water of its branchial chamber when exposed to atmospheric air.
• 5.5. The oxygen consumption and activity are reduced when the animals are exposed to atmospheric air. The reduction in the oxygen consumption may be related to the poorly adapted respiratory system, while the decrease in activity may be a mechanism for saving energy during this hypoxic period.

     

Blood changes in japanese eels,Anguilla japonica,experimentally infected with typical or atypicalAeromonas salmonicida

• 1.1. Changes in the blood and in the rate of oxygen consumption of Japanese eels injected intramuscularly in the head with a lethal dose of typical or atypical Aeromonas salmonicida at 20°C were investigated.
• 2.2. Eels infected with the bacteria became moribund within 4 to 6 days, and then died within 1 day.
• 3.3. The O₂ consumption rate and blood parameters changed markedly with infections. The responses of hosts to infection by the two kinds of bacteria differed with regard to the following four points: blood pH, plasma Cl⁻, lactic acid, and the numbers of granulocytes and lymphocytes.
• 4.4. The responses of eels infected with atypical A. salmonicida were larger and more rapid than those of eels infected with typical A. salmonicida.

     

Functional properties of the two major hemoglobin components from Leporinus friderici (Pisces)

• 1.1. The hemoglobins of Leporinus friderici were separated by liquid chromatography on DEAE-Sepharose in order to isolate the two major electrophoretic components.
• 2.2. The chromatographic fraction I (electrophoretically slow anodic) showed no Bohr effect and no nucleoside triphosphate modulation.
• 3.3. The chromatographic fraction III (electrophoretically fast anodic) showed a normal Bohr effect and addition of nucleoside triphosphate decreased oxygen affinity but did not alter the Bohr effect.
• 4.4. The whole hemolysate showed a normal Bohr effect and phosphate modulation altered both Bohr effect and oxygen affinity.
• 5.5. No or little difference between the effect of adenosine or guanosine triphosphates on hemoglobin function was observed.

     

Deterioration of chum salmon (Oncorhynchus keta) muscle during spawning migration—III. Changes in protein composition and protease activity of juvenile chum salmon muscle upon treatment with sex steroids

• 1.1. Changes in protein composition and protease activity of juvenile chum salmon muscle upon treatment with sex steroids were investigated.
• 2.2. A slight breeding color was observed on chum salmon following the oral administration of 17α-methyltestosterone. Sarcoplasmic protein significantly decreased, while ninhydrin-positive substances from protein-free fractions significantly increased upon treatment with 17α-methyltestosterone. Autolytic activity of the fish treated with 17α-methyltestosterone drastically increased.
• 3.3. Estradiol-17β did not significantly influence the protein composition and autolytic activity.
• 4.4. These results indicate that androgen is closely related to the deterioration of chum salmon muscle.

     

Morphometry and composition of red drum otoliths: Changes associated with temperature,somatic growth rate,and age

• 1.1. Size and composition of sagittal otoliths from red drum, Sciaenops ocellatus (Sciaenidae), reared at various constant temperatures were compared with otoliths from wild-caught fish.
• 2.2. Uncoupling of otolith growth and somatic growth in laboratory-reared fish was evident in otolith length, area, volume, weight, density, and organic fraction.
• 3.3. Fish grown at low temperatures had significantly smaller and less dense otoliths having a greater organic content than fish of the same size grown at higher temperatures.
• 4.4. Changes in inorganic elements were poorly related to temperature in laboratory-reared fish.
• 5.5. The effect of temperature on otolith elemental composition was small relative to the effects of age and its associated physiological changes.

     

Blood volume recovery in hemorrhaged japanese quail

• 1.1. Blood volume and plasma biochemical changes and feed and water consumption in response to a hemorrhage by phlebotomy of 30% of the calculated total blood volume with and without replacement of blood volume with physiological saline were determined in juvenile male Coturnix coturnix japonica.
• 2.2. Plasma protein and osmolality decreased rapidly posthemorrhage and did not recover by 72 hr posthemorrhage.
• 3.3. Plasma glucose, Na⁺ and K⁺ increased within Ihr postphlebotomy. Plasma Na⁺ returned to nonphlebotomized levels within 6 hr postphlebotomy.
• 4.4. Saline replacement of blood volume resulted in hypervolemia within 3–5 min postphlebotomy.
• 5.5. Phlebotomized quail receiving no saline recovered blood volume to 0 hr (nonphlebotomized) levels within l hr postphlebotomy.