The effect of dietary protein level and ration level on excretion of ammonia in common carp,Cyprinus carpio

• 1.1. Nitrogenous excretion in the form of ammonia was determined in common carp of 65.0 ± 8.0 g body weight in metabolism chambers. The fish were fed with 20, 35 and 50% dietary protein at 1, 2 and 3% body weight per day ration level.
• 2.2. Nitrogenous excretion as a percentage of ingested food increased with an increase of dietary protein but decreased with an increase of ration level.
• 3.3. The energy lost in excretion ranged from 4.19% with 20% dietary protein at 3% ration level to 8.74% with 50% dietary at 1% ration level.

     

Specific dynamic action and feeding metabolism in common carp,Cyprinus carpio L.

• 1.1. Oxygen uptake attributable to Specific Dynamic Action (SDA) was measured in common carp, Cyprinus carpio L. (63.6–84.0 g) fed on 20, 35 and 50% dietary protein at 0.40 to 1.00% ration levels at 28°C.
• 2.2. After feeding both SDA magnitude and mean peak oxygen consumption increased directly with dietary protein and ration levels. SDA duration was not significantly related to dietary protein but significantly increased with ration levels.
• 3.3. SDA coefficients were 8.99, 13.51 and 15.94% with 20, 35 and 50% dietary protein showing a direction relationship to the protein content. The SDA coefficient did not change with ration size.
• 4.4. SDA models resulting from this work are of great interest for the aquaculturist, as post-feeding oxygen requirements in an intensive fish culture can be predicted where dietary protein and ration levels are known.

     

Growth and haematological response of sturgeon hybrids Russian sturgeon (Acipenser guldenstadti brandt) × beluga (Huso huso L.) to protein and lipid contents in the diet

• 1.1. Fingerlings of intergenious hybrid Russian sturgeon (Acipenser guldenstadti) × beluga (Huso huso) weighing 22 g reared in water with salinity 18 ppt were fed nine diets differing in protein and fat content.
• 2.2. The increase of dietary protein content (from 45 to 52%) improved the fingerlings growth rate, food and protein conversion efficiencies. No effect of further protein content increase to 60% was observed.
• 3.3. The increase of dietary fat content from 10 to 20% positively influenced all growth results.
• 4.4. The muscular lipid content increased following the increase in dietary fat due to accumulation of triacylglycerols.
• 5.5. Distinctive leucopenia in neutrophils and leucophilia in lymphocytes following dietary protein and fat content increase were observed.
• 6.6. It was concluded that within the analysed range of values the increase of dietary protein and lipid content improved the physiological status of sturgeon hybrid fingerlings.

     

Sea-water tolerance in freshwater-resident arctic charr (Salvelinus alpinus)

• 1.1. Freshwater-resident Arctic charr acclimated for 2 months at 8°C, 15% were divided into four experimental groups in July and exposed to 1 and 8°C in 15 and 34% salinity.
• 2.2. Only slight changes in gill Na-K-ATPase activity, blood plasma osmolality and blood plasma concentrations of Cl⁻ and Mg²⁺ were found for the fish exposed to 1 or 8°C in brackish water.
• 3.3. When exposed to sea-water at 8°C, an increase in osmolality and in concentrations of Cl⁻ and Mg²⁺ took place during the first 2–3 days, after which it levelled off.
• 4.4. If exposed to sea-water at 1°C, however, marked increases were found for all parameters measured and all the fish were dead within 5 days of exposure.
• 5.5. These results show that freshwater-resident Arctic charr—if acclimated to brackish water—can survive in sea-water during summer if the environmental temperature is not too low.

     

Breeding and moulting fasts in macaroni penguins: Do birds exhaust their fat reserves?

• 1.1. Plasma concentrations of urea, uric acid and total lipid were compared in pre- and late-fast breeding and moulting macaroni penguins (Eudyptes chrysolophus) to test the hypothesis that birds exhaust their lipid reserves and initiate marked protein utilisation towards the end of natural fasts.
• 2.2. Male and female macaroni penguins fasted for a minimum of 29–32 days and 20 days during the breeding and moult fasts, and the difference in body weight over the sample period (reflecting body weight loss) was 31–34% and 41–47%, respectively.
• 3.3. There was no significant increase in plasma urea or uric acid at the end of either fast, nor any decrease in plasma lipid concentrations compared to pre-fast birds.
• 4.4. These results suggest that macaroni penguins continue to rely mainly on lipid reserves during the later stages of natural fasts. This is consistent with post-fast body composition data for other small penguin species.

     

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.

     

Dietary supplementation of vitamin E fails to prevent the development of hyperoxic lung injury in the premature guinea pig

• 1.1. The benefit of dietary vitamin E supplementation in preventing oxidative-induced lung injury was investigated. Three day preterm guinea pig pups were exposed to hyperoxic (85% O₂) or normoxic (21% O₂) conditions. The animals were fed either a standard low birthweight human infant formula milk (6.4 mg/l vitamin E), or a vitamin E supplemented milk (100 mg/l) for up to 7 days.
• 2.2. After 3 days vitamin E supplementation, plasma but not erythrocyte vitamin E concentrations were elevated, while following 7 days both plasma and erythrocyte vitamin E concentrations were significantly increased.
• 3.3. Lung and liver vitamin E concentrations were elevated at both 3 and 7 days. At 3 days the increase in lung vitamin E was oxygen-dependent, suggesting that the lung increases uptake of vitamin E in response to oxidative stress.
• 4.4. Despite an increase in the vitamin E concentration of the lungs of preterm guinea pigs, no amelioration of the lung injury was observed. These results suggest that although vitamin E is a potent antioxidant, it is unable to protect adequately the lungs from reactive oxygen species in the absence of sufficient primary enzymatic antioxidant defences.

     

Plasma lipid transport in the horse (Equus caballus)

• 1.1. Equine plasma contains lipoproteins corresponding to very low density (VLDL), low density (LDL) and high density lipoproteins (HDL).
• 2.2. HDL accounts for approximately 60% of plasma lipoprotein mass and consists of a single population of particles.
• 3.3. LDL is heterogeneous comprising three discrete subfractions.
• 4.4. Two proteins are found in the region of apolipoprotein (apo) B-100 in VLDL and LDL and a third similar to apo B-48 is in VLDL.
• 5.5. Lecithin:cholesterol acyl transferase is active in plasma and hepatic lipase and lipoprotein lipase are evident in post-heparin plasma.
• 6.6. There is no significant cholesteryl ester transfer protein activity.

     

Effect of dietary coconut oil on lipoprotein composition of young chick (Gallus domesticus)

• 1.1. The composition of HDL, the major lipoprotein fraction from chick serum, drastically changed after 2 weeks of coconut oil feeding. Total cholesterol and triacylglycerols significantly increased following dietary 10 or 20% coconut oil supplementation.
• 2.2. Changes in LDL composition were less profound, cholesterol being the only component that increased by coconut oil supplementation (10 or 20%).
• 3.3. IDL proteins were the only components that increased following the same dietary treatment (20%).
• 4.4. VLDL cholesterol and proteins also increased after 1–2 weeks of 20% coconut oil supplementation to the diet.
• 5.5. Of total lipoproteins, the cholesterol content strongly increased after dietary treatment, while triacylglycerols did not change significantly.

     

Sex-specific androgen binding in spotted hyaena (Crocuta crocuta) plasma

• 1.1. A charcoal adsorption assay demonstrated a large variance in androgen binding ability in female spotted hyaenas.
• 2.2. A positive correlation between plasma androgen binding ability and ovarian steroid concentrations was demonstrated in adult females.
• 3.3. The strong plasma binding affinity for testosterone and dihydrotestosterone (DHT) (nM) together with the lack of cortisol and weaker oestradiol-17β binding suggests that a specific androgen binding substance, possibly a protein, is present in adult females of this species.
• 4.4. The lack of high affinity binding in male spotted hyaenas is unusual and deserves further investigation.
• 5.5. Some androgen binding in all, including males and immature animals suggests that albumin may bind some plasma androgens in this species.

     

Cold tolerance of steinernematid and heterorhabditid nematodes

• 1.1. Nematodes survive subzero temperatures using either a freeze-avoiding or freezing-tolerant strategy. Steinernema anomali, S. feltiae, and Heterorhabditis bacteriophora were all found to be freezing tolerant.
• 2.2. The lower lethal temperatures were −22, −19 and −14°C for S. feltiae, H. bacteriophora and S. anomali, respectively.
• 3.3. Survival after prolonged freezing at −4°C was 6, 5 and 3 days for S. feltiae, H. bacteriophora and S. anomali, respectively.
• 4.4. Acclimation to lower temperatures increased freezing tolerance. The freezing tolerance of Heterorhabditis bacteriophora increased under a stepwise acclimation regime; S. feltiae acclimated better under a direct acclimation regime.

     

The glycogen content in stressed marine bivalves: The initial absence of a decrease

• 1.1. Changes in the glycogen content, condition, stomach content and acetic acid concentration of mussels Mytilus edulis and cockles Cerastoderma edule were followed during periods of up to 14 days of exposure (to air) at temperatures of 5 and 20°C.
• 2.2. In animals with a high glycogen content the glycogen is not used during the first 3 to 7 days, at high and low temperature respectively.
• 3.3. After this latent period the glycogen concentration often decreased, coinciding with a high mortality and an increase of the concentration of acetic acid.
• 4.4. In cockles with a low glycogen content, and kept at a high temperature, glycogen can be used from the beginning of the stress period.
• 5.5. Between species no clear differences were found.
• 6.6. The stomach content decreased during exposure; however, the stomach content amounted to only 0.5 to 0.7% of the body weight, and is thought to be of minor importance as an energy source during the stress period.
• 7.7. Especially at the higher temperatures glycogen finally is transformed into acetic acid.
• 8.8. It is concluded that during exposure, the animals do not die because of a lack of energy reserves, but because of a high accumulation of acids.

     

The peculiarities of nitrogen excretion in sturgeons (Acipenser ruthenus) (Pisces,Acipenseridae)—I. the influence of ration size

• 1.1. The nonfaecal nitrogenous excretion rate in starved sterlet fingerlings and fingerlings fed on different rations was investigated. The weight of the fish and temperature of the water was 43 g and 17.5°C, respectively.
• 2.2. In the nonfaecal excrements of starved sterlets the ammonia: urea ratio was substantially lower than in teleosts. This ratio was found to be 1.4:1.
• 3.3. In fed sterlets the urea excretion rate was higher than in starved ones but independent of ration size.
• 4.4. During the day the urea excretion rate in sterlets was constant.
• 5.5. The ammonia excretion rate accelerated 2 hr after feeding and reached its peak duration 6–11 hr after depending on the ration size.
• 6.6. Total ammonia output in the sterlet increased following the increase of ration size up to 8.4% of body wt. Further increases in ration size did not cause the corresponding elevation of ammonia excretion rate.

     

Increased muscle glucose uptake in response to chronic glyburide treatment is not related to changes in glucose transporter (GLUT4) protein

• 1.1. The mechanism of action of glyburide (a sulfonylurea) on muscle has been investigated by measuring glucose uptake and glucose transporter (GLUT4) protein levels after chronic glyburide treatment.
• 2.2. A dietary induced insulin resistant rat model (4 wk of high-fat, high-sucrose feeding) was given glyburide (2mg/kg/day) for 10 days and glucose uptake was measured in a perfused hindquarter preparation.
• 3.3. Protein levels of the GLUT4 glucose transporter were determined by Western analysis.
• 4.4. After 7 days of treatment, rats fed glyburide had lower blood glucose concentrations 2 hr (72 ± 5 vs 103 ± 12 mg/dl) and 24 hr (97 ± 7 vs 123 ± 7 mg/dl) after glyburide administration with no difference in serum insulin levels compared to vehicle treated animals.
• 5.5. Glucose uptake was approx doubled in basal state (0 insulin) in response to glyburide (2.8 + 0.4 vs 1.7 ± 0.2μ mol/g per hr).
• 6.6. Maximal insulin (100 nM) stimulated glucose uptake tended to be higher in the glyburide treated group, but did not reach statistical significance (8.0 ± 0.7 vs 7.0 ± 0.6 μmol/g per hr).
• 7.7. Western analysis revealed no significant effect of glyburide on the GLUT4 protein level in skeletal muscle.
• 8.8. These results suggest that glyburide alters glucose uptake through some mechanism other than alterations in the level of the GLUT4 glucose transporter protein.

     

Anuran amphibia which are not acclimable to high salt,tolerate high plasma urea

• 1.1. The capacity of five anuran Amphibians (Bufo viridis B. regularis, Rana ridibunda, Hyla arborea and Pelobates syriacus) to acclimate to NaCl and urea solutions was investigated.
• 2.2. All species could be acclimated to relatively high concentrations of urea solutions, while only Bufo viridis and Hyla arborea could be acclimated to 500 mOsm/kg or higher NaCl solutions.
• 3.3. The plasma urea concentration in B. viridis and H. arborea was elevated to levels over 140 mmol/1.
• 4.4. The sum of plasma sodium and chloride concentrations did not increase over 400 mmol/l in any species.
• 5.5. Urine osmolality, which was normally low, increased, but never exceeded the plasma osmolality.
• 6.6. In the urea acclimation conditions, urine electrolytes diminished, similarly in all species in this study.
• 7.7. It is concluded that anuran Amphibians can tolerate high plasma urea concentrations, but only those species which can elevate it, either through retention or net synthesis, can be acclimated to high salt solutions.

     

A comparison of serum retinol concentration between human and different species of normo and hypercholesterolemic nonhuman primates fed semi-purified diets with defined amounts of vitamin A

• 1.1. Serum retinol and total cholesterol concentrations were determined in several species of nonhuman primates fed semipurified diets. Two species of Old World and three species of New World nonhuman primates were examined.
• 2.2. Retinol levels were significantly lower (up to four-fold) in the serum of the smaller New World than the larger Old World animals and the difference could not be explained by differences in dietary make-up.
• 3.3. Cholesterol levels were not different between the groups but differed within a species when type of dietary fat was altered.
• 4.4. Differences in circulating levels of retinol may reflect differences in levels of retinol binding protein between the groups.

     

Changes in body composition of germ-free and conventional chickens during starvation

• 1.1. Changes in body composition during starvation were compared between germ-free (GF) and conventionalized (CVL) chicks in experiment 1. At 8 days of age, the GF birds were divided into two groups, i.e. GF and CVL groups. The CVL birds were inoculated with faeces from conventionally reared birds. Until 14 days of age, both birds were fed a diet ad lib, and thereafter starved for 6 days.
• 2.2. Nitrogen loss during starvation was significantly lower in CVL birds, though the reverse was true for water loss. Fasting heat production was comparable between two environments.
• 3.3. Influence of the gut microflora on body weight and nitrogen losses during starvation was investigated in birds prefed diets high or low in dietary protein in experiment 2.
• 4.4. No significant effect of the gut microflora was observed in body weight and nitrogen losses. Body weight was severely reduced in birds prefed the high protein diet and nitrogen loss was lower in birds prefed the low protein diet.

     

Transport of cholesterol in the hemolymph of the mollusc Diplodon delodontus

• 1.1. The dietary and inter-organ cholesterol transport in the hemolymph of the bivalve mollusc Diplodon delodontus, was studied. Plasma and hemocytes were obtained after feeding labeled cholesterol to animals or injecting it into the posterior adductor muscle.
• 2.2. In both cases, cholesterol was incorporated either into plasma or hematic cells.
• 3.3. Two plasmatic fractions differing in their hydrated densities were recognized as cholesterol carriers and were isolated. They have characteristics of high density (HDL) and very high density (VHDL) lipoproteins, respectively.
• 4.4. The major lipids in the different classes of lipoproteins were free sterols in HDL and phospholipids in VHDL.
• 5.5. Neither low nor very low density lipoprotein transporting cholesterol was detected.

     

Freeze tolerance and intolerance as strategies of winter survival in terrestrially-hibernating amphibians

• 1.1. The ability to tolerate extracellular freezing as an adaptation for winter survival was tested in seven species of terrestrially-hibernating amphibians found in eastern Canada.
• 2.2. All species had only moderate supercooling abilities, with whole animal supercooling points of −1.5 to −3°C.
• 3.3. Two salamander species, Plethodon cinereus and Ambystoma laterale, and the toad, Bufo americamts, were freezing intolerant and were killed when frozen for 24 hr at temperatures just below their supercooling points. The major winter strategy of these animals appears to be behavioural avoidance of subzero temperatures.
• 4.4. Four species of frogs Rana sylvatica, Hyla versicolor, Hyla crucifer and Pseudacris triseriata, survived extracellular freezing at moderate subzero temperatures (−2 to −4°C) for periods of time ranging up to 2 weeks.
• 5.5. All four frog species accumulated low molecular weight carbohydrates as cryoprotectants, glycerol being the major cryoprotectant in adult H. versicolor, while immature adults of this species as well as the other three species all produced high levels of glucose as the cryoprotectant.

     

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.