Determination of benzo(a)pyrene in isopods (Porcellio scaber Latr.) exposed to contaminated food

• 1.1. A method is presented for the determination of the polycyclic aromatic hydrocarbon benzo(a)pyrene (BaP) in the isopod Porcellio scaber, using reversed-phase HPLC with fluorescence detection.
• 2.2. This technique has a detection limit for BaP in P. scaber of approximately 3.2 ng g⁻¹ fresh weight.
• 3.3. BaP was assimilated from food by P. scaber.
• 4.4. After four weeks of ad libitum feeding on BaP-contaminated food, concentrations in the isopods were approximately 30–40 times lower than those in the food.
• 5.5. Male and female isopods did not differ in BaP concentration. Variation among males seemed to be much higher than among females.

     

Specific dynamic action (SDA) in the supralittoral isopod,Ligia pallasii: Identification of components of apparent SDA and effects of dietary amino acid quality and content on SDA

• 1.1. Specific Dynamic Action (SDA) effects of diet were investigated in the supralittoral isopod, Ligia pallasii, using defined chemical diets.
• 2.2. “Apparent SDA”, or the total rise in metabolic rate following a meal, was resolved in animals eating a nutritionally complete chemical diet into three components: 8% mechanical costs of moving food through the gut, 40% “excitement costs” due to investigator disturbance and presence of food, and 52% SDA.
• 3.3. Excitement costs in animals exposed to food but which chose not to eat showed non-significant variation between diets containing different levels of chemical nutrients, but were significantly less on a diet containing only cellulose and agar.
• 4.4. SDA increased with increasing concentration of amino acids in the diet.
• 5.5. Substitution of whole-protein casein for free amino acids in the diet had no significant SDA effect, while substitution of free amino acids in the ratio found in casein more than doubled the SDA effect.
• 6.6. Deletion of alanine from the diet caused no significant effect on SDA, while deletion of phenylalanine caused a highly significant elevation in SDA.

     

Apparent and real variability in the presence and metal contents of metallothioneins in the crab Carcinus maenas including the effects of isolation procedure and metal induction

• 1.1. Reducing conditions must be maintained throughout the procedure of isolating metallothioneins from crabs. Dithiothreitol is preferred to 2-mercaptoethanol for long-term protection.
• 2.2. Two metallothioneins (10,100 and 4100 mol. wt, respectively) in the hepatopancreas of the crab Carcinus maenas showed great variability between individual crabs as to their presence and to their contents of Zn, Cu and Cd.
• 3.3. The 10,100 mol. wt metallothionein was induced in the laboratory by exposure to Cu and Cd, and variably by Zn-exposure. Laboratory induction did not raise significantly the total metal content of 0.88 ± 1.13 g atoms/mol protein of this metallothionein in crabs from the Firth of Clyde, Scotland.
• 4.4. The 4100 mol. wt metallothionein was not induced in the laboratory by exposure to Cu, Cd or Zn. This metallothionein in crabs from the Firth of Clyde, Scotland, contained 0.27 ± 0.34 g atoms of total Cu, Cd and Zn per mole of protein.

     

Binding and detoxification of heavy metals in lower vertebrates with reference to metallothionein

• 1.1. The metabolism of Cu, Zn, Cd and Hg in lower vertebrates is described, using fish as a model.
• 2.2. The main part of this review deals with metallothionein and the role of this protein for the storage and detoxification of these metals.
• 3.3. Factors influencing the bioavailability and probable uptake routes are identified.
• 4.4. The distribution of the metals within the organism is outlined. The distribution between tissues is described and the subcellular distribution discussed with reference to metallothionein.

     

Effects of aluminium and pH on calcium fluxes,and effects of cadmium and manganese on calcium and sodium fluxes in brown trout (Salmo trutta L.)

• 1.1. Simultaneous measurement of calcium fluxes in brown trout, at low external [Ca] (20 μ mol 1⁻¹), provided evidence of active uptake of Ca from the medium.
• 2.2. At pH 4.5, calcium influx was inhibited and efflux was stimulated.
• 3.3. Cd and Mn, but not Al, at concentrations within the ranges found in acid waters experiencing fish population decline, inhibited calcium influx. Efflux was unaffected.
• 4.4. Cd and Mn stimulated sodium influx and efflux.

     

Specific dynamic action (SDA) in the supralittoral isopod,Ligia pallasii: Relationship of growth to SDA

• 1.1. The relationship of Specific Dynamic Action (SDA) to growth was examined in the supralittoral isopod Ligia pallasii using a seaweed diet fed at different rations.
• 2.2. Animals increased in live weight by 33% on an ad libitum or 100% diet and by 2% on a 20% ration over a 10-week period.
• 3.3. Weight-specific VO₂ was significantly higher in animals eating the 100% diet than in ones eating the 20% diet. Decline in VO₂ with time in animals on the 20% diet was probably due to poor health associated with a maintenance ration.
• 4.4. SDA per unit weight of food eaten was 18% higher in the 20% diet group than in the 100% one, and values remained constant over time in both groups.
• 5.5. k₁ growth efficiencies (production/consumption) were higher in animals on 100% ration than in ones on 20% ration. Efficiencies declined with time in both diet-groups and fell below zero in the 20% ration-group, coincidental with weight-loss in some of the animals.
• 6.6. Overall SDAs for the 10-week period were positively correlated with growth (r₂ = 0.77), but there was no way to separate this from amounts eaten as an effect on SDA.

     

A histopathological analysis of wild and transplanted Dreissena polymorpha from the dutch sector of the river maas

• 1.1. The histopathology of zebra mussel populations (Dreissena polymorpha) which were transplanted and exposed in baskets in the Dutch sector of the River Maas (5 locations) were compared with indigenous wild mussels at the same locations and at a clean reference site in the Ijsselmeer.
• 2.2. All groups were sectioned histologically and examined to quantify cytological damage and pathology of a wide range of tissues, as well as to examine parasitology and to assess their reproductive state.
• 3.3. Results show a significant reduction in general cytological quality and an increase in observed pathological conditions in the wild populations at the 3 downstream stations.
• 4.4. The transplanted (active biomonitoring) groups of mussels clearly showed a similar trend in condition after only 42 days exposure at these sites.
• 5.5. The influence of an industrial spillage of Cd in the Maas during the exposures is examined against this background of locally varying “health”.

     

Structural and functional effects of heavy metals on the nervous system,including sense organs,of fish

• 1.1. Today, fish in the environment are inevitably exposed to chemical pollution. Although most hazardous substances are present at concentrations far below the lethal level, they may still cause serious damage to the life processes of these animals.
• 2.2. Fish depend on an intact nervous system, including their sense organs, for mediating relevant behaviour such as food search, predator recognition, communication and orientation.
• 3.3. Unfortunately, the nervous system is most vulnerable and injuries to its elements may dramatically change the behaviour and consequently the survival of fish.
• 4.4. Heavy metals are well known pollutants in the aquatic environment. Their interaction with relevant chemical stimuli may interfere with the communication between fish and environment.
• 5.5. The affinity for a number of ligands and macromolecules makes heavy metals most potent neurotoxins.
• 6.6. The present Mini-Review highlights some aspects of how trace concentrations of mercury, copper and lead affect the integrity of the fish nervous system; structurally, physiologically and biochemically.

     

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.

     

Specific dynamic action (SDA) in the supralittoral isopod,Ligia pallasii: Effect of ration and body size on SDA

• 1.1. Ration and body size effects on specific dynamic action (SDA) were investigated in the supralittoral isopod Ligia pallasii using seaweed and chemical diets.
• 2.2. SDA increased asymptotically with ingested meal size for all diets.
• 3.3. Body weight had a significant positive effect on SDA for only one of the six diets tested, but weak tendencies were present in the data for the other diets.
• 4.4. SDA appeared to increase geometrically with increasing concentration of amino acids at high ration levels.

     

Genetic variation in the nine rainbow trout (Oncorhynchus mykiss) populations in South Africa

• 1.1. Twenty-six protein coding loci in nine populations of rainbow trout, from different localities in South Africa, were analyzed by starch and polyacrylamide gel electrophoresis to estimate the amount of genetic diversity present.
• 2.2. Heterozygosity ranged between 0.0445 and 0.0745.
• 3.3. The relatively high heterozygosity levels are probably due to the historical mixing of strains, and the differences in heterozygosity indicate that the populations originate from different sources, each with different genetical characteristics.
• 4.4. Differences in phenotypic characters (i.e. growth) seem to relate to genotypic variation, whilst food conversion rate and survival performance results did not seem to relate to genotypic variation.

     

Internal reference standards in ionic regulation and the predictability of ionic concentrations in animals

• 1.1. The regulation of ions at similar concentrations in most individuals of a species suggests the existence of internal reference standards.
• 2.2. Few have been identified, but many probably relate to cell membrane properties, including potentials, surface charge densities and equilibrium constants of receptor molecules.
• 3.3. Solubility may sometimes determine the product [Ca²⁺][CO₃²⁻].
• 4.4. Reference standards must generally each relate to more than one ionic species.
• 5.5. For some concentrations, including osmolality, there may be no direct reference standard.

     

Analysis of postembryonic development of locomotor activity rhythm by corpora allata implantation in the cricket gryllus bimaculatus

• 1.1. Male crickets Gryllus bimaculatus show a drastic change in circadian rhythm from nymphal diurnality to adult nocturnality, in association with an increase in activity level several days after the imaginai moult.
• 2.2. The corpora allata implantation into male 7th or 8th instar nymphs produced supernumerary instar nymphs in about 30% of the implanted animals, but did not affected the normal development in the remaining animals.
• 3.3. The majority of the supernumerary instar nymphs were diurnal and sexually inactive, although their internal reproductive organs appeared to be fully mature.
• 4.4. The supernumerary instar nymphs became nocturnal with an increase in activity level several days after the imaginai (9th) moult.
• 5.5. The roles of the nervous system in the regulation of the rhythm reversal are discussed.

     

Hemocyanin in Oniscus asellus (Isopoda)

• 1.1. An immunological crossreactivity, as demonstrated by Western blotting, exists between O. asellus hemocyanin and anti-keyhole limpet (Megathura crenulata) hemocyanin.
• 2.2. Using the anti-keyhole limpet hemocyanin, the presence of hemocyanin was detected in the hepatopancreas.
• 3.3. The amino acid composition of the hemocyanin of O. asellus was found to be similar to that of other isopods.

     

Correlation of acid phosphatase but not alkaline phosphatase activity with myelination in the developing mouse brain

• 1.1. Neonatal mice received subcutaneous injections of buffer, thiourea (TU) or propylthiouracil (PTU).
• 2.2. The PTU-treated mice were sacrificed on postnatal day 14 (P14) and the TU-treated mice on P28.
• 3.3. Brain weights of the TU- and PTU-treated mice were not significantly different from the controls.
• 4.4. Acid but not alkaline phosphatase activity in the braistem decreased after TU and PTU treatment.
• 5.5. Myelination as indicated by intensity of luxol fast blue staining was weaker in drug-treated animals.
• 6.6. The level of myelin marker enzyme, 2′,3′-cyclic nucleotide 3′-phosphohydrolase, was lower in the brainstem of PTU-treated animals.
• 7.7. The results suggest a correlation between acid phosphatase but not alkaline phosphatase activity with myelination in the developing mouse brain.

     

Environmental and genetic influences on the thermal physiology of Rana sylvatica

• 1.1.|Intraspecific variation in the thermal physiology of Rana sylvatica was examined.
• 2.2.|Heat and cold tolerances of both adult and larval representatives were determined for animals representing populations from New York, Maryland, Kentucky, Ohio, Michigan and Canada.
• 3.3.|In general, frogs from more northern localities exhibited lower heat tolerances.
• 4.4.|There was no evidence of interpopulational differences in cold tolerance. Similar trends were revealed by larval testing.
• 5.5.|Interpopulational differences among laboratory-reared tadpoles suggests a strong genetic component to Rana sylvatica thermal physiology.

     

Stimulatory effect of amp on the copper ion dependent oxidation of adrenaline to adrenochrome

• 1.1. AMP markedly activated copper ion dependent oxidation of adrenaline to adrenochrome. It is proposed that a Cu(II)-AMP chelate forms a reactive complex with adrenaline.
• 2.2. AMP did not affect copper stimulated oxidation of noradrenaline, dopamine and l-dopa.

     

Genetic variability in south african blue wildebeest (Connochaetes taurinus)

• 1.1. We used protein gel-electrophoresis to investigate genetic heterogeneity at 33 protein coding loci in a total of 46 blue wildebeest (C. taurinus) kept under different management regimes.
• 2.2. Average heterozygosity ranged from 2.14 to 4.3% and within-population differences accounted for 97.2% of total relative gene diversity.
• 3.3. Comparatively little divergence was found between animals sampled from populations with very diverse population sizes and management histories, with the largest genetic distance estimated between any two populations being only 0.0021.
• 4.4. We discuss our results with particular emphasis on the influence of management history on genetic diversity and divergence in C. taurinus.

     

Time-dependent cadmium-neurotoxicity in rat brain synaptosomal plasma membranes

• 1.1. The modulation of lipid dynamics and lipid protein interactions were studied in rat brain synaptosomal plasma membranes (SPM) up to 24 hr after exposure to cadmium (Cd).
• 2.2. The activity of acetylcholinesterase and adenylate cyclase showed a considerable decrease after 6 hr of Cd exposure, followed by a progressive increase up to 24 hr.
• 3.3. SPM chemiluminescence showed a maximum decrease at 12 hr, demonstrating a considerable increase in lipid peroxidation.
• 4.4. SPM of Cd-exposed animals showed a statistical significant increase in fluorescence anisotropy parameter [(r₀/r) — 1]⁻¹ at 18 and 24 hr compared to SPM of the control, indicating a decrease of membrane fluidity.