Correlation of water translocation,cuticle dehydration and post-ecdysial sclerotization by the american cockroach

• 1.1. Haemolymph volume decreases during the initial 16 hr post-ecdysial period, increases after water ingestion and subsequently drops until the inter-ecdysial level is reached.
• 2.2. Total body water follows a similar pattern, but the changes are not as pronounced.
• 3.3. Tissue water is inversely proportional to the total body water.
• 4.4. Soluble cuticle protein declines throughout the initial 16 hr period while both β-glucosidase and alkaline phosphatase activity is lost within 6 hr after ecdysis.
• 5.5. Dehydration of the cuticle also occurs during the immediate 6 hr post-ecdysial period.
• 6.6. These data suggest that the formation of the protein-insoluble matrix is linked with water loss.
• 7.7. Water removal may decrease the distance between molecules allowing specific reactions to take place.

     

Metabolic utilization of leucine in a fat and a lean line of chicken

• 1.1. In vivo incorporation into body lipids and breast muscle proteins from l-[U-¹⁴C]leucine was studied in genetically lean or fat male chickens, fed or starved, 1 or 24 hr after intraperitoneal injection.
• 2.2. Lipogensis and portein synthesis from labelled leucine were significantly higher in fat chickens than in lean birds, particularly in those in the fed state.
• 3.3. Radioactivity in the free amino acid pool was greater in fat birds irrespective of the nutritional state.
• 4.4. However, utilization of injected l-[U-¹⁴C]leucine for lipogenesis was no more than 2%.

     

The effect of feed restriction on certain haematological indices,enzymes and metabolites in Nubian goats

• 1.1. Some effects of restricting feed intake for 96 or 168 hr were determined in male Nubian goats.
• 2.2. Goats restricted for 96 hr lost 11.6% of their body weight, and goats restricted for 168 hr lost 19.8%.
• 3.3. Feed restriction for up to 168 hr did not produce significant effects on the heart rate, respiratory rate or rectal temperature.
• 4.4. Haemoglobin concentration, packed cell volume and erythrocyte number were all decreased by feed restriction. There was also a tendency towards eosinopenia and lymphopenia.
• 5.5. Feed restriction for 96 or 168 hr raised the plasma activity of aspartate transaminase, and did not affect significantly cholinesterase activity. Plasma amine oxidase activity was significantly reduced in goats restricted for 168 hr.
• 6.6. Feed restriction produced significant increases in the blood or plasma concentrations of lactate. pyruvate, non-esterified fatty acids, cholesterol, ketone bodies and bilirubin.
• 7.7. Significant decreases were found in the concentrations of total protein and calcium.
• 8.8. No significant changes were observed in the plasma concentrations of glucose, sodium or potassium.

     

Metabolic and behavioral responses of American kestrels to food deprivation

• 1.1. The effect of short-term (79 hr) food deprivation at 27°C on body mass, locomotor activity, body temperature (T_b), and resting oxygen consumption was determined in eleven American kestrels (Falco sparverius).
• 2.2. The change in body mass during resting followed the relation, % mass remaining = 99 e^{0.07(days fasting)}. There was no significant difference in the rate of relative mass loss between males and females.
• 3.3. Locomotor activity, measured as perch hopping, was highly variable in both control and fasted birds and showed no correlation with stage of the fast, basal metabolic rate (BMR), or rate of mass loss during food deprivation.
• 4.4. Body temperatures of fasted birds declined continuously by 0.2–0.4°C per day from 39.3 to 38.3°C.
• 5.5. Both males and females responded to food deprivation with a decrease in metabolism. By the third night of fasting, BMR had declined 23.4% from 0.845 W (bird day)⁻¹ to 0.647 W (bird day)⁻¹. The observed reduction in BMR is 2.4 times that expected from a 1°C decline in T_b (assuming Q₁₀ = 2.5) indicating active suppression of metabolism.

     

Reduced muscle protein breakdown in septic rats following treatment with interleukin-1 receptor antagonist

• 1.1. The role ofinterleukin-1 (IL-1) in sepsis-induced muscle proteolysis was assessed by treating septic rats with recombinant IL-1 receptor antagonist (rIL-Ira).
• 2.2. In initial experiments, we tested the effectiveness of IL-Ira in preventing muscle proteolysis induced by administration of IL-1.
• 3.3. When normal rats were treated with rIL-α (three intraperitoneal doses of 100 μ g/kg body weight each over 16 hr), total and myofibrillar muscle protein breakdown rates, measured as release oftyrosine and 3-methylhistidine, respectively, by incubated extensor digitorum longus muscles, were significantly increased.
• 4.4. This metabolic response to IL-α was completely abolished by rIL-Ira, administered as three intraperitoneal doses of 3 mg/kg body weight each over 16hr.
• 5.5. In subsequent experiments, sepsis was induced in rats by cecal ligation and puncture (CLP); non-septic rats were sham-operated.
• 6.6. Treatment of septic rats over 16hr with a total dose of 25mg/kg body weight of rIL-Ira reduced, but did not normalize, the increased muscle protein breakdown rates seen during sepsis.
• 7.7. When the dose of rIL-Ira was more than doubled and given as a constant infusion at a rate of 4.2 mg/kg body weight/hr for 16 hr, the increased rate of muscle proteolysis in septic rats was normalized.
• 8.8. The present study offers the first direct evidence that IL-1 is involved in the regulation of muscle proteolysis during sepsis.

     

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.

     

Urea excretion rates and waste nitrogen concentrations during metamorphosis of Xenopus laevis Daudin

• 1.1. Serum urea, ammonia concentrations in the blood and excretion were measured in tadpoles of different stages and juveniles of Xenopus laevis.
• 2.2. The urea excretion rate was determined with the help of injected ¹⁴C-urea.
• 3.3. Urea concentrations are higher during metamorphic climax and at the end of metamorphosis than during prometamorphosis.
• 4.4. Blood ammonia levels remain rather constant throughout metamorphosis.
• 5.5. Coincidentally, the relative amount of urea in the blood increases.
• 6.6. The ¹⁴C-urea excretion rates slow down from very high values (48%/hr) at the beginning of prometamorphosis to low rates (5%/hr) in newly metamorphosed animals.
• 7.7. This means that during metamorphosis not only is the possibility of urea production established. but there is a capacity to retard and store urea to some extent.

     

Purine metabolism in cotyledons and embryonic axes of black gram (Phaseolus mungo L.) Seedlings

• 1.1. The metabolism of purine bases and nucleosides in cotyledons and embryonic axes of black gram (Phaseolus mungo L.) was studied.
• 2.2. A large portion of absorbed [8-¹⁴C]adenine, [8-¹⁴C]guanine and [8-¹⁴C]adenosine was salvaged in nucleotide and nucleic acid synthesis.
• 3.3. Most of the radioactivity of [8-¹⁴C]hypoxanthine and [8-¹⁴C]inosine was incorporated into allantoin and allantoic acid.
• 4.4. Activity of adenine phosphoribosyltransferase in enzyme extracts was much higher than that of hypoxanthme and guanine phosphoribosyltransferase(s).
• 5.5. Apparent activity of adenosine kinase was higher than that of inosine kinase. 6. NAD⁺-dependent xan thine dehydrogenase was detected in both cotyledons and embryonic axes of the seedlings.
• 6.7. The capacity of purine salvage was higher m 24 hr old cotyledons than 24 and 48 hr old embryonic axes. The reverse was observed concerning that of purine degradation.

     

Food consumption,assimilation and rate of food passage in the cape rock elephant shrew,Elephantulus edwardii (macroscelidea: Macroscelidinae)

• 1.1. Food consumption, assimilation and passage rates of an elephant shrew, Elephantulus edwardii, on three natural diets (cockroaches, locusts and termites) and one artificial cereal diet (Pronutro) were compared.
• 2.2. Daily food consumption varies significantly between the diets and was partly related to % assimilation, which was highest on Pronutro and cockroaches (71%) and lowest on termites (31%).
• 3.3. Throughput times were estimated using soluble (⁵¹ Cr-EDTA) and particulate markers in the Pronutro diet. First appearance of the soluble marker (0.5 hr) was significantly earlier than for the particulate marker (1.85 hr); 50% appeared at 3.2 and 3.35 hr for the soluble and particulate markers, respectively.
• 4.4. The distribution of particulate markers in the digestive tract showed some retention in the stomach, ileum and colon, but rapid movement through the duodenum and very little entry to the caecum.

     

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.

     

Alterations in proteases,protease inhibitors and ecdysone levels: a profile of stress in insects

• 1.1. A comparison of proteolytic and protease inhibitory activity, and ecdysteroid levels in body fluids was made between normal larvae of the flesh fly, Sarcophaga bullata, and those that had been water-stressed for two days.
• 2.2. The course of proteolytic activity in water stressed flies decreases 6 hr after beginning the experiment and remains low in comparison with control flies.
• 3.3. The course of protease inhibitors exhibits a mirror image pattern to proteases.
• 4.4. Ecdysteroid pattern shows two peaks in control animals: minor at 24 hr and major at pupariation, in experimental animals: at 1 hr, at 6 hr and at white pupal stage.

     

Kinetic studies of vitellogenin metabolism in the elasmobranch Scyliorhinus canicula L.

• 1.1. The appearance of vitellogenin in the plasma of adult female Scyliorhinus canicula and its subsequent disappearance and conversion into yolk granules were monitored by an isotopic method. Rates of vitellogenin synthesis in different fish were compared.
• 2.2. There was considerable individual variation in the rate of synthesis and in the plasma half-life of vitellogenin; measured values of the latter ranged from 132 to 303 hr (mean 216 hr) at 7 ± 2°C.
• 3.3. Winter temperature stimulated vitellogenin synthesis in midsummer, but winter photoperiod did not do so.
• 4.4. Captivity without food for 22 days reduced the rate of vitellogenin synthesis in summer but had no effect in winter.

     

Acute toxicity and bioaccumulation of endosulfan in rotifer (Brachionus calyciflorus)

• 1.1. The acute toxicity of endosulfan was determined for the freshwater rotifer Brachionus calyciflorus.
• 2.2. The mean 24 hr lc₅₀ value for endosulfan was 5.15 ppm with a coefficient of variation of 14.7%.
• 3.3. Rotifers were exposed at two sublethal concentrations (1.5–2.0 ppm) of endosulfan for bioaccumulation experiments, for an exposure time of 24, 48, 72 and 96 hr. The rotifers were fed with Nannochloris oculata (5 × 10⁵cell/ml).
• 4.4. The highest accumulation of endosulfan was found 24 hr after the start of the exposure to 1.5 ppm of the toxicant. A steady-state concentration in rotifer was reached between 24–48 hr, followed by a gradual decrease until 96 hr.

     

Sulphate conjugation is the main route of pentachlorophenol metabolism in Daphnia magna

• 1.1. Daphnia magna were exposed for 24 hr to ¹⁴C-labelled pentachlorophenol (PCP) at an initial concentration of 20μg/l in the incubation water. Occurrence of free PCP and its metabolites were measured both from the animals and the water.
• 2.2. Hydrophilic metabolites excreted into water were analysed, after acid or enzymatic hydrolyses, with a liquid-liquid extraction and TLC.
• 3.3. PCP was metabolized and excreted, perhaps solely, via the sulphate conjugation. The average excretion rate, 2.65nmol/g/hr, accounted for 35% of the absorption rate measured at the start of exposure.
• 4.4. Neonate daphnids had an equal ability to metabolize PCP as the older animals. Bioconcentration in young animals was, however, only 23% of that in adult ones.
• 5.5. Effect of naturally humic water on metabolization and excretion of PCP was negligible.

     

Electrolyte changes,cell volume regulation and hormonal influences during acclimation of rainbow trout (Salmo gairdnerii) to salt water

• 1.1. Rainbow trout were acclimated to salt water (1.5, 2.0 or 3.0%, which means 40, 60 or 85% concentrated sea-water) and the electrolyte, glucose and cortisol concentrations of the plasma as well as the extra- and intracellular muscle space, the muscle electrolyte concentrations and the ATPase activity were analysed.
• 2.2. Plasma osmolality, Na⁺, Ca²⁺ and Mg²⁺ concentrations of the plasma had a maximum at 24 hr after the start of acclimation when acclimated to 3.0% salt water. Plasma osmolality, Na⁺ and Mg²⁺ concentrations were significantly higher during the whole acclimation time when exposed to 3.0% salt water.
• 3.3. Variations and regulations of ECS and ICS were clearly demonstrated. The intracellular electrolyte concentrations were also maximal at 24 hr.
• 4.4. The plasma glucose level was just slightly elevated, but the cortisol level clearly indicated a stress response at 24 hr.
• 5.5. The activity of gill Na-K-ATPase increased during the acclimation time.
• 6.6. The regulatory processes in trout during acclimation to salt water are compared with those occurring in tilapia and carp.

     

Evoked effects of oestradiol on hepatic cholesterol 7α-hydroxylase and drug oxidase in castrated rats

• 1.1. Oestradiol administration in castrated rats resulted in an increased activity of the cholesterolα-hydroxylase and a decreased activity of the drug oxidase enzyme systems.
• 2.2. Aqueous solutions of oestradiol (up to 25·10⁻⁶M) incubated in vitro with microsomes, binds into the microsomal membrane framework reducing the activity of both enzyme systems.
• 3.3. The specific activity of cholesterol 7α-hydroxylase. drops after 3 hr preincubation with oestradiol to at least 70% of its original value.
• 4.4. Actinomycin D and cycloheximide administration reduced the oestradiol-induced and control cholesterol 7α-hydroxylase activity to the same level, 6 hr after the injections.

     

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.

     

The dynamics of the permeation of an analogue of insect juvenile hormone into nematodes

• 1.1. ¹⁴C-dichlorofarnesoate permeated rapidly into Haemonchus contortus (infective juveniles) and Panagrellus redivivus (mixed cultures) and was strongly bound by hydrophobic association (K_s > 10⁻⁴M).
• 2.2. Uptake rose linearly with increases in temperature (5–38°C) and external concentration (C₀; 0.07–2.15 × 10⁻⁴ M). Within 1 hr the internal concentration, C₁ was >C C₀.
• 3.3. The pH of the medium (6–8) did not affect uptake.
• 4.4. Efflux of dichlorofarnesoate was low: the half-time of release was > 18 hr.
• 5.5. The uptake curve approximated to the expression C₁/C₀ = a(1 − e^−bt) with a and b as constants and t in hr.
• 6.6. These results clarify previous work on the inhibitory action of juvenile hormone on the development of nematodes.

     

Sex and tissue specific patterns of protein synthesis and turnover in the free-living nematode Panagrellus redivivus

• 1.1. A pulse-chase autoradiographic study of incorporation of ³H-leucine into body-wall, digestive and reproductive tissue of virgin adult Panagrellus redivivus demonstrates both tissue and sex-specific patterns of protein biosynthesis and turnover.
• 2.2. Female body wall has a higher rate of protein synthesis and turnover than male body wall.
• 3.3. Uptake of leucine into macromolecule in the digestive tissue is more rapid in males than females, as is the rate of turnover.
• 4.4. The ovary is more rapidly labelled than the testis, with a much more rapid turnover rate.

     

Some effects of dehydration on internal distributions of water and solutes in Xenopus laevis

• 1.1. In relation to body weight changes resulting from evaporative water losses of up to 37% of initial body weight:
  • 1.1.(a) Plasma chloride and potassium concentrations increased in proportion to total body water losses.
  • 1.2.(b) Plasma urea concentrations increased at greater rates than expected from the sum of basal synthesis and dehydration.
  • 1.3.(c) Plasma sodium concentrations initially increased less rapidly than expected from total body water losses, but by losses of 30% of initial body weight closely approximated predicted concentrations.
  • 1.4.(d) Plasma volumes decreased slightly faster than expected, while hematocrits increased as expected.
• 2.2. Skeletal muscles and the ventricular muscles of the heart retained water to greater degrees than expected. Dehydration did not elicit net shifts in Na⁺ K⁺, Cl⁻ or amino acids between the intracellular and extracellular compartments in either skeletal muscle or ventricle.