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At least 271 records · Page 15Linked to original sources

PubMed2002

Fictive locomotion induced by octopamine in the earthworm.

We investigated the function of octopamine (OA) as a motor pattern inducer in the earthworm Eisenia fetida. We used semi-intact preparations, consisting of 20 sequential segmental ganglia of the ventral nerve cord (VNC) together with the body wall from the middle of the animal. Bath-application of 10(-4) mol l(-1) OA to the semi-intact preparation induced phasic muscle contractions, which are consistent with crawling. In the isolated VNC, OA induced bursts of motor neuron activity in the first lateral nerves. Burst frequency increased with OA concentration, with a large increase in activity observed in the range 10(-6)-10(-4) mol l(-1). At 10(-4) mol l(-1), the coefficient of variation of burst periods (BPs) was smaller than that seen upon application of OA at other concentrations, which is indicative of rhythmic bursts. These rhythmic bursts propagated along the VNC from the anterior to posterior, with a propagation velocity ranging from 60 to 110 mm s(-1). This velocity is consistent with the propagation velocity of muscle contraction during crawling behavior in the intact earthworm. From these results, we conclude that fictive crawling motor patterns are observed at 10(-4) mol l(-1) OA, and that OA can induce rhythmic bursts in the isolated VNC of the earthworm.

Adrenergic alpha-Agonists↗

PubMed1997

Extrusion of earthworm coelomocytes: comparison of the cell populations recovered from the species Lumbricus terrestris, Eisenia fetida and Octolasion tyrtaeum.

Coelomocytes were extruded from three earthworm species: Lumbricus terrestris, Eisenia fetida and Octolasion tyrtaeum. Featuring a simple low-vacuum holding device, the proposed methodology allows the recovery of cells with minimum risk of contamination by faecal material. The viability of O. tyrtaeum coelomocytes was highly reproducible (average 93%), with an average yield of 0.92 x 10(6) viable cells per earthworm. Cell viability for L. terrestris and E. fetida averaged approximately 68% but the cell yields were higher (respectively 1.67 x 10(6) and 1.28 x 10(6)). Large inter-individual differences in cell yields were observed with L. terrestris. Flow cytometric analyses indicated species to species differences in cell populations. Coelomocytes from E. fetida were the smallest with approximately 57% of the total viable cells recovered being monitored between 2 and 10 microns. Large granulated cells (> or = 20 microns) were detected in fairly large proportions in L. terrestris and O. tyrtaeum (approximately 52 and approximately 96%, respectively) while they were less abundant in E. fetida (approximately 9%). Using the vital dye neutral red to assess functional integrity, average cellular uptakes were significantly higher for L. terrestris and O. tyrtaeum than for E. fetida (2.94, 2.66 and 0.64 micrograms/2 x 10(5) cells, respectively). In summary, the extrusion methodology herein described is applicable for the recovery of coelomocytes from a wide range of earthworm sizes and species. Moreover, this study strengthens the fact that extruded coelomocytes could be used for the evaluation of cell dysfunction and/or cell death following an in vitro and/or in vivo treatment.

Animals↗

PubMed2006

Stereoselective reduction of carbonyl compounds using the cell-free extract of the earthworm, Lumbricus rubellus, as a novel source of biocatalyst.

We found the reducing activity toward carbonyl compounds in the cell-free extract of the earthworm, Lumbricus rubellus. The earthworm extract had a reducing activity for keto esters in the presence of NADH or NADPH as a coenzyme. The earthworm extract reduced ethyl 3-methyl-2-oxobutanoate to the corresponding alcohol with a high enantiomeric excess (91%, R-form) at 50 degrees C in the presence of NADH. In particular, ethyl 2-oxoheptanoate was exclusively reduced to the corresponding (R)-hydroxyl ester with a high enantiomeric excess (>99%).

Animals↗

PubMed2005

An isozyme of earthworm serine proteases acts on hydrolysis of triacylglycerol.

An enzyme catalyzing the hydrolysis of triacylglycerol was purified from an earthworm. The N-terminal amino acid sequence and the catalytic function of the purified enzyme were identical to those of Isozyme C, an isozyme of the earthworm-serine proteases. No other lipase proteins were found in the earthworm cells. The isozyme might act on the hydrolysis of triacylglycerol as well as the protein decomposition.

Animals↗

PubMed2003

Lead and stable lead isotope ratios in soil, earthworms, and bones of American woodcock (Scolopax minor) from eastern Canada.

A study to discriminate among different possible sources of elevated Pb exposure for American woodcock (Scolopax minor) in eastern Canada is described. Undamaged wing bones excised from young-of-the-year woodcock collected from several locations in southern Ontario, southern Quebec, New Brunswick, and Nova Scotia, Canada, along with soil and earthworm (Aporrectodea tuberculata and Lumbricus rubellus) samples from the same sites, were analyzed for total Pb, and stable Pb isotopes. Ignoring six soil samples with high (> 60 microg/g) Pb concentration from the vicinity of Montreal (QC, Canada), the mean soil-Pb concentration for all sites combined was 19 microg/g (dry wt; n = 64), with a mean 206Pb:207Pb ratio of 1.19, values typical for uncontaminated rural soils in eastern North America. In earthworms, Pb concentrations ranged from 2.4 to 865 (microg/g [dry wt], mean = 24 microg/g). Concentrations of Pb in worms and soils were positively correlated (r = 0.71; p < 0.01), and 206Pb:207Pb ratios for worms and soils were also positively correlated (r = 0.54; p < 0.05). However, most young-of-the-year woodcock with high bone-Pb accumulation (> 20 microg/g) had 206Pb:207Pb ratios substantially different from worms and soils sampled from the same areas, even though woodcock feed extensively on soil invertebrates, especially earthworms. The range of 206Pb:207Pb ratios in wing bones of woodcock with elevated Pb exposure was not consistent with exposure to environmental Pb from past gasoline combustion nor Precambrian mining wastes but was consistent with ingestion of spent Pb shotgun pellets.

Animals↗

PubMed2006

Improvement of the applicability of ecotoxicological tests with earthworms, springtails, and plants for the assessment of metals in natural soils.

The environmental risk assessment of metals in the soil compartment is based mainly on tests performed in Organization for Economic Cooperation and Development (OECD) artificial soil, but ecologically, the use of natural soils would be more relevant. In this contribution, the reproduction and growth of three standard species (an earthworm, a collembolan, and a dicotyledonous plant, respectively) was evaluated in nine natural soils (covering a wide range of pH values, organic matter content, texture, and so on) and in OECD artificial soil. Afterward, the effects of the model chemical zinc nitrate were assessed in all soils that were identified as being suitable for these species. The test results indicate that the toxicity of zinc nitrate can be higher by a factor of approximately four compared to artificial soil for invertebrates (earthworms and collembolans), whereas plants are only slightly more sensitive in some natural soils than in artificial soil. When comparing the different endpoints, it could be confirmed that the median effective concentration (EC50) is the most robust compared to the highly uncertain 10% effective concentration. Decreasing toxicity of zinc nitrate to collembolans was significantly correlated with an increase in soil pH but not with cation exchange capacity (CEC) or organic carbon (OC) content. No significant correlation was found between the toxicity of zinc nitrate to earthworms or plants and soil pH, CEC, or OC content. Possible consequences of the results are discussed, such as the testing of natural soils in addition to the OECD artificial soil or the inclusion of an additional safety factor to use the EC50 in current risk assessment schemes focusing on no-observed-effect concentrations.

Animals↗

PubMed2006

Biological significance of metals partitioned to subcellular fractions within earthworms (Aporrectodea caliginosa).

Metal ions in excess of metabolic requirements are potentially toxic and must be removed from the vicinity of important biological molecules to protect organisms from adverse effects. Correspondingly, metals are sequestrated in various forms, defining the accumulation pattern and the magnitude of steady-state levels reached. To investigate the subcellular fractions over which Ca, Mg, Fe, Cu, Zn, Cd, Pb, Ni, and As are distributed, earthworms (Aporrectodea caliginosa) collected from the field were analyzed by isolating metal-rich granules and tissue fragments from intracellular microsomal and cytosolic fractions (i.e., heat-stable proteins and heat-denatured proteins). The fractions showed metal-specific binding capacity. Cadmium was mainly retrieved from the protein fractions. Copper was equally distributed over the protein fraction and the fraction comprising tissue fragments, cell membranes, and intact cells. Zinc, Ca, Mg, and As were mainly found in this fraction as well. Lead, Fe, and Ni were mainly isolated from the granular fraction. To study accumulation kinetics in the different fractions, three experiments were conducted in which earthworms were exposed to metal-spiked soil and a soil contaminated by anthropogenic inputs and, indigenous earthworms were exposed to field soils. Although kinetics showed variation, linear uptake and steady-state types of accumulation patterns could be understood according to subcellular compartmentalization. For risk assessment purposes, subcellular distribution of metals might allow for a more precise estimate of effects than total body burden. Identification of subcellular partitioning appears useful in determining the biological significance of steady-state levels reached in animals.

Animals↗

PubMed2001

Effect of beringite on cadmium and zinc uptake by plants and earthworms: more than a liming effect?

Metal-contaminated soils are potentially harmful to plants, animals, and humans. Harmful effects are often related to the free-metal concentration in the soil solution. Immobilization is a potentially useful method to improve the quality of metal-contaminated soils by transforming free-metal ions into species that are less mobile and less toxic. The effect of many immobilizing products can be attributed to sorption on the surface of the material. Alkaline materials also enhance adsorption to soil particles by decreasing proton competition. Immobilization should preferably be evaluated independently of soil pH to discriminate between these processes. In this study, the immobilizing effect of beringite, an alkaline alumino silicate, was compared with that of lime. Plants (Swiss chard [Beta vulgaris L. var. cicla]) were grown on a soil contaminated with cadmium and zinc and treated with graded amounts of beringite or lime. Metal availability, as determined by a 0.01 M CaCl2 extraction, and metal uptake by plants strongly decreased in all treated soils. Beringite did not reduce metal availability more than liming when the obtained pH levels were similar. The effect of beringite can, therefore, be explained as a liming effect, at least for the duration of our experiment (10 weeks). The effect of beringite and lime on metal accumulation by earthworms (Eisenia veneta and Lumbricus rubellus) was small or not significant, although the CaCl2-extractable metal concentration in treated soils decreased by more than 90%. We conclude that immobilizing agents based on a liming effect can decrease metal uptake by plants, but they will hardly affect metal uptake by earthworms. Hence, these materials can reduce negative ecological effects of metal contamination on plants and herbivores, but not on earthworm predators.

Aluminum Silicates↗

PubMed2000

Participation of electrogenic Na+-K+-ATPase in the membrane potential of earthworm body wall muscles.

The effect of Na+-K+-ATPase inhibitor ouabain on the resting membrane potential (Vm) was studied by glass microelectrodes in isolated somatic longitudinal muscles of the earthworm Lumbricus terrestris and compared with frog sartorius muscle. In earthworm muscle, Vm was -49 mV (inside negative) in a reference external solution with 4 mmol/l K+. The electrogenic participation of Na+-K+-ATPase was absent in solutions with very low concentrations of 0.01 mmol/l K+, higher in 4 and 8 mmol/l K+ (4-5 mV) and maximal (13 mV) in solutions containing 12 mmol/l K+ where Vm was -46 mV in the absence and -33 mV in the presence of 1 x 10(4) M ouabain. The electrogenic participation of Na+-K+-ATPase was much smaller in m. sartorius of the frog Rana temporaria bathed in 8 and 12 mmol/l K+. The results indicate that the Na+-K+-ATPase is an important electrogenic factor in earthworm longitudinal muscle fibres and that its contribution to Vm depends directly on the concentration of K+ in the bathing solution.

Animals↗

PubMed1992

[The composition of phospholipid and biosynthesis of platelet-activating factor in earthworm (Eisenia foetida)].

Platelet-activating factor (PAF) was for the first time confirmed to exist in a lower animal, earthworm (Eisenia foetida). It amounts to 10.7 +/- 6.1 pmol/g wet body weight, and varied seasonally. Phospholipid analysis revealed that 1-O-alkyl-2-acyl-sn-glycerophosphocholine, a stored form of PAF precursor, accounted for 61.4% of the choline glycerophospholipids. Two kinds of enzyme activities operating in PAF generation in mammalian cells were also detected from this species. The PAF level increased markedly under some injurious stimuli such as cutting and pricking. The results suggest that PAF may be a primary mediator involved in pathological and physiological reactions even in lower animal like earthworm. The findings also cast a new light on the mechanisms underlying the antihypertensive and other effects of the Chinese medicinal earthworm, pheretima.

Animals↗

PubMed2003

[Factor optimization for municipal domestic wastes treatment by earthworms and its concentration of heavy metals].

Simulated experiments, plot tests and applied stuties were conducted to determine the effects of the composition of municipal domestic wastes, their softening and culturing methods, and circumstance temperature on the treatment of municipal domestic wastes (MDW) by earthworms. The results showed that the decomposition rate of MDW and the multiplication rate of earthworms could be elevated by enhancing the C/N ratio of MDW, softening it with earthworms excrements, and culturing with indoor layer at 20 degrees C. Meanwhile, the treatment of MDW was also improved by the hybridization of tamed Chongqing Aisenia foetida and Caliginsoa. The concentration coefficient of heavy metals had no correlation with intenerating method, but were depended upon the types of heavy metals and the culturing method. Arsenic and cadmium were the most easily concentrated, while mercury oppositely. The concentration element in ridge culture was more easily than that in layer culture, and the concentration element in outdoors culture was more easily than that in indoors culturing.

Animals↗

PubMed2004

[Earthworm feces-induced systemic resistance of cucumber against anthracnose].

Pot experiment showed that mixing earthworm feces into soil induced a significantly lower (P < 0.05) cucumber anthracnose than mixing peat, but had no significant difference (P > 0.05) with the treatment of system acquired resistance. The activities of polyphenol oxidase, peroxidase and phenylalanine ammonia-lyase in cucumber leaves treated with and without pathogen were increased in different degrees by mixing earthworm feces, compared with by mixing peat. All these suggested that mixing with earthworm feces could induce the system resistance of cucumber and suppress the plant disease via starting up the recovery enzyme system in plant.

Animals↗

PubMed2005

Biodiversity of earthworm resources of arid environment.

Biodiversity of earthworms was studied in arid zone of Jodhpur district of Rajasthan. A total nine species of earthworms were recorded from different pedoecosystems of desert environment. These species were Pontoscolex corethrurus, Amynthas morrisi, Metaphire posthuma, Lampito mauritii, Perionyx sansibaricus, Ocnerodrilus occidentalis, Dichogaster bolaui, Octochaetona paliensis and Ramiella bishambari. They belonged to the families Glossoscolicidae, Megascolicidae, Ocnerodrilidae and Octochaetidae. The species P. sansibaricus, O. paliensis and P. corethrurus were reported for the first time from Rajasthan. The earthworm fauna of Jodhpur district were either exotic peregrine or native peregrine. Exotic species like A. morrisi and M. posthuma, and native peregrine species like L. mauritii were widely distributed in arid region. They appear to be better adapted to withstand drought conditions, as they have enteronephric meronephridia and excrete their urine into the guts for conservation of water in their bodies.

Animals↗

PubMed2006

Autofluorescence in eleocytes of some earthworm species.

Immunocompetent cells of earthworms, coelomocytes, comprise adherent amoebocytes and granular eleocytes (chloragocytes). Both cell populations can be expelled via dorsal pores of adult earthworms by exposure to an electric current (4.5 V) for 1 min. Analysis by phase contrast/fluorescence microscopy and flow cytometry demonstrated that eleocyte population of several species exhibits a strong autofluorescence. A high percentage (11-35%) of autofluorescent eleocytes was recorded in Allolobophora chlorotica, Dendrodrilus rubidus, Eisenia fetida, and Octolasion sp. (O. cyaneum, O. tyrtaeum tyrtaeum and O. tyrtaeum lacteum). In contrast, autofluorescent coelomocytes were exceptionally scarce (less than 1%) in representative Aporrectodea sp. (A. caliginosa and A. longa) and Lumbricus sp. (L. castaneus, L. festivus, L. rubellus, L. terrestris). Thus, this paper for the first time describes profound intrinsic fluorescence of eleocytes in some--but not all--earthworm species. The function (if any) and inter-species differences of the autofluorescent coelomocytes still remain elusive.

Animals↗

PubMed2006

[Research advance in antibacterial immunity ecology of earthworm].

Earthworm lives in the environment flocked with pathogens, but few are infected due to the earthworm's unique antibiotic and immune system. In this paper, the research advance in this domain was reviewed from the aspects of antibiotic barrier, cell immunity, and humoral immunity. Antibiotic barrier mainly includes body wall, alimentary canal and parietal mucus, cell immunity represents phagocytosis and encapsulation responses, while humoral immunity gives priority to unspecific immune system. The main antibacterial materials in the coelomic fluid of earthworm are antigen-binding proteins, agglutinins, antibacterial proteins, and lysozyme.

Animals↗

PubMed1977

[Resistance of earthworms Lumbricus terrestris and Allolobophora turgida to the fungicide captan 50 W.P].

Two species of earthworms were kept in Muck, Chicot and Ste-Sophie soils treated with captan 50 W.P. solutions of 700, 1 400 and 2 800 ppm. After a 42-day treatment period, L. terrestris had a 95% survival and A. turgida 100% survival. Using a gas chromatograph method, no captan was detected in tissue extracts of exposed earthworms. Based on the survival rate and the undetected presence of captan in earthworm tissues, we concluded that soil residues of this product are unlikely to be harmful to the animal's ecology.

Animals↗

PubMed1995

Epifluorescent microscopy of earthworms' intestinal bacteria.

Epifluorescent microscopy was employed to compare the bacterial live counts (BC) in the gut of two earthworm species Aporrectodea caliginosa and Lumbricus rubellus, representing different ecophysiological groups. The average number of BC was 10.9 x 10(9) g-1 dry weight in the gut of A. caliginosa, 5.9 x 10(9) in that of L. rubellus, 8.1 x 10(9) in earthworm casts and 6.0 x 10(9) in the soil. The number of BC showed a great seasonal variability in all the materials studied, exhibiting maxima in spring and autumn, and a minimum in summer. The BC increased in number during the passage of food material through the gut of both L. rubellus and A. caliginosa. The difference between BC in fore-gut and hind-gut were significantly higher in L. rubellus (4.2 x 10(9) vs. 8.8 x 10(9)) than that in A. caliginosa (10.3 x 10(9) vs. 13.4 x 10(9)). Interspecific differences in the number of BC may result from the different chemical and microbiological composition of the material consumed by earthworms as related to different feeding habits of both species.

Animals↗

PubMed1996

The comet assay for the detection of genotoxic damage in the earthworms: a promising tool for assessing the biological hazards of polluted sites.

The comet assay, a relatively new method for DNA strand break detection in individual cells, is becoming a major tool for environmental biomonitoring. One approach for assessing the possible environmental consequences of hazardous waste pollution involves the assessment of genotoxic damage (and other effects) in sentinel organism. The single cell gel electrophoresis (SCGE) technique or comet assay. because of its simplicity, sensitivity, and need for only small numbers of cells, has been suggested as an ideal technique for such studies. An important advantage of the technique is that it is applicable to any eukaryotic organism and cell type. Verschaeve et al. (1993) conducted a pilot study using alkaline comet assay to assess the extent of DNA damage in coelomic leucocytes (coelomocytes) of earthworms (Eisenia foetida) maintained in different soil samples as an indicator of soil pollution. The aim of our study was to evaluate the usefulness of monitoring single strand breaks in coelomocytes for assessing genotoxicity of pollutants in coke oven area. We exposed earthworms to samples of soils obtained from polluted areas of a coke oven. All samples gave a significantly higher comet tail moment that those obtained from worms kept in laboratory conditions (standard black earth = internal controls) and worms kept in soils from control areas (= external controls). Our results show that the comet assay applied to earthworm is very valuable for monitoring and detection of genotoxic compounds in terrestrial ecosystems.

Animals↗