Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Neutral Red”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources
PubMed1994

Comparative in vitro effects of sodium arsenite and sodium arsenate on neuroblastoma cells.

The toxic effects of arsenic at different cellular levels were assessed using two inorganic chemical species: sodium arsenite and sodium arsenate, representing the trivalent and pentavalent states of arsenic, respectively. Mouse neuroblastoma cell cultures (Neuro-2a) were exposed for 24 h, and cytotoxic effects evaluated were: cell proliferation by quantification of total protein content; cytoplasmic membrane integrity to cytosolic lactate dehydrogenase leakage; lysosomal hexosaminidase release; lactate dehydrogenase activity; mitochondrial succinate dehydrogenase activity; relative neutral red uptake by lysosomes; lysosomal hexosaminidase sphingolipid degradation activity; and acetylcholinesterase activity. As(III) was found to be five times more toxic than As(V) to neuroblastoma cell proliferation, but the relative extent of other alterations differed. Special sensitivity was detected for lactate dehydrogenase inhibition. Hexosaminidase activity was also very susceptible, being inhibited at low concentrations and stimulated at high concentrations. Less sensitive were the inhibition of cell proliferation, relative neutral red uptake, and acetylcholinesterase activity. As(III) was lysosomotropic, with secretion of hexosaminidase, but the release was decreased by As(V). Mitochondrial succinate dehydrogenase was inhibited by As(III) and stimulated by As(V). Minor sensitivity to cytoplasmic lactate dehydrogenase leakage for both compounds also shows that functional metabolic alterations produced by arsenic are more important than structural damage.

Acetylcholinesterase↗
PubMed2005

Biomarker response and biomass change of earthworms exposed to chlorpyrifos in microcosms.

Background levels of chlorpyrifos and earthworm abundance were determined in an orchard and adjacent areas on a farm in the Western Cape, South Africa before these areas were again sprayed with this organophosphate. The background concentrations ranged from 0.2 microg/kg dm in the spray drift area adjacent to the orchard to 10.18 microg/kg dm on the slope in the run off area. In the target area the chlorpyrifos concentrations varied from a mean of 15.25 +/- 10.0 microg/kg directly after spraying to a mean of 7.0 +/- 0.9 microg/kg 6 months later and in the nontarget area they varied from a mean of 55.0 +/- 35 microg/kg to 12.0 +/- 5 microg/kg after 6 months. Chlorpyrifos was therefore still present in the field soils, but at lower concentrations, up to 6 months after the last spraying event. Earthworm abundance and population densities were very low. Only Aporrectodea caliginosa was found and the densities were much lower in the orchards (22 per m(2)) than in the nontarget areas (98.3 per m(2)). Microcosm studies were undertaken to relate biomarker responses to chlorpyrifos with biomass changes. Microcosms were filled with soil from the same areas and earthworms of the species A. caliginosa were introduced. The microcosms were treated with a series of concentrations of chlorpyrifos in the laboratory under controlled conditions. These concentrations were chosen to fall within the background ranges found in the soils. The biomass of the worms was determined regularly for a period of 5 weeks and worms in a state of estivation were noted. Earthworms were removed from the microcosms for biomarker tests: for cholinesterase (ChE) inhibition assays every week and for a neutral red retention determination 2 weeks after the exposures started. The most prominent biomass loss was noted in earthworms exposed to the highest pesticide concentration of 8.0 microg/kg. Estivation was higher among earthworms exposed to higher exposure concentrations. Inhibition of ChE increased with higher exposure concentrations and with time but there was no clear dose-related response. A clear dose-related response with exposure concentration was established for the neutral red retention assay. A correlation between ChE inhibition and biomass change existed directly after the second application of chlorpyrifos.

Animals↗
PubMed1996

Analysis of cell movement during the culmination phase of Dictyostelium development.

Co-ordinated cell movement of tens of thousands of cells and periodic signals characterise the multicellular development of the cellular slime mould Dictyostelium discoideum. We investigated cell movement by analysing time-lapse video recordings made during the slug stage and the culmination phase of Dictyostelium development. Slugs viewed from the side showed an even, straight forward movement with the tip slightly raised in the air. Slugs that had migrated for a prolonged period of time either culminated or showed a behaviour best described as abortive culmination. Culmination is initiated by a local aggregation of anterior-like cells at the base of the slug at the prestalk-prespore boundary, where they form a stationary mass of cells. Prespore cells continue to move forward over this stationary pile and, as a result, are lifted into the air. The stationary group of anterior-like cells thereby end up to the back of the slug. At this point the slug either falls back on the agar surface or continues culmination. If the slug continues to migrate these cells regain motility, move forward to the prespore-prestalk boundary and form a new pile again. In the case of culmination the neutral red stained cells in the pile move to the back of the slug and form a second signalling centre beside the tip. Both centres are characterised by vigorous rotational cell movement. The cells belonging to the basal centre will form the basal disc and the lower cup in the fruiting body. The upper cup will be formed by the prestalk cells rotating most vigorously at the prestalk-prespore boundary. The remaining neutral red stained anterior-like cells in the prespore zone sort either to the upper or lower organising centre in the fruiting body.

Animals↗
PubMed1966

Plaque formation by Teschen disease virus and the effect of certain associated factors.

A plaque assay method was developed for Teschen disease virus using primary pig kidney cultures in which neutral red stain was incorporated in the agar overlay medium. Certain factors associated with the plaque-forming ability of the virus were standardized. Cultures allowed to adsorb the virus for 45-60 minutes at 28 and 37 C, gave maximal plaque count. The virus infected the cellular layer through the agar medium. Plating efficiency of the virus was enhanced by using a small volume of inoculum. Addition of serum to the medium was not required. Neutral red concentration in the agar overlay medium affected the number of plaques. Statistical analysis demonstrated the uniformity of the plaque counts and their linear relationship to virus concentration. Isolation of the virus by the plaque technique from infected spinal cord supernatant fluid was achieved.

Animals↗
PubMed1966

Inactivation of foot-and-mouth disease virus by interaction of dye and visible light.

The inactivation of foot-and-mouth disease virus was studied by means of the interaction of neutral red, Toluidine Blue, and methylene blue with visible light. The virus, Type A, strain 1, CANEFA of Argentine origin, was grown in tissue culture and tested in the crude and clarified state. Virus and dye were mixed and incubated together at 4 C for 45 min in the dark, or were mixed and immediately exposed to the visible light source without prior incubation together. Mixtures of crude virus and dye, under any of the experimental conditions used, did not inactivate more than 1 to 2 logs of viral infectivity when held in the dark or when exposed to light during a period of 45 min. Complete inactivation of virus was achieved when clarified virus and dye were mixed and immediately exposed to the visible light source for 15 min. Prior incubation of clarified virus and dye permitted inactivation by methylene blue only, whereas no incubation prior to exposure resulted in three of the dyes contributing to inactivation. A concentration of 6 mug of neutral red, Toluidine Blue, methylene blue, and crystal violet was used per milliliter of virus suspension. Crystal violet was not a good viral inactivator under the conditions of the experimentation. Inactive virus induced the formation of neutralizing antibodies in adult chickens and mice. The antibody titer stimulated by the antigen treated with methylene blue and visible light was probably significant.

Animals↗
PubMed1978

Electron acceptors associated with P-700 in Triton solubilized photosystem I particles from spinach chloroplasts.

Flash-induced absorption changes of Triton-solubilized Photosystem I particles from spinach were studied under reducing and/or illumination conditions that serve to alter the state of bound electron acceptors. By monitoring the decay of P-700 following each of a train of flashes, we found that P-430 or components resembling it can hold 2 equivalents of electrons transferred upon successive illuminations. This requires the presence of a good electron donor, reduced phenazine methosulfate or neutral red, otherwise the back reaction of P-700+ with P-430 occurs in about 30 ms. If the two P-430 sites, designated Centers A and B, are first reduced by preilluminating flashes or chemically by dithionite under anaerobic conditions, then subsequent laser flashes generate a 250 microseconds back reaction of P-700+, which we associate with a more primary electron acceptor A2. In turn, when A2 is reduced by background (continuous) illumination in presence of neutral red and under strongly reducing conditions, laser flashes then produce a much faster (3 microseconds) back reaction at wavelengths characteristic of P-700. We associate this with another more primary electron acceptor, A1, which functions very close to P-700. The organization of these components probably corresponds to the sequence P-700-A1-A2-P-430[AB]. The relation of the optical components to acceptor species detected by EPR, by electron-spin polarization or in terms of peptide components of Photosystem I is discussed. Preliminary experiments with broken chloroplasts suggest that an analogous situation occurs there, as well.

Chlorophyll↗
PubMed1996

Antitumor activity of thevetoside in vitro.

OBJECTIVE: To study the effects of thevetoside (TS), a cardiac glycoside, and an inhibitor of Na+, K(+)-ATPase, on tumor cells cultured in vitro. METHODS: The cytotoxic effects of TS on tumor cells were determined by trypan blue dye exclusion, neutral red vital staining and clonogenic assay. The time-effect relationship and growth inhibition of tumor cells by TS were assayed with trypan blue exclusion method. RESULTS: TS at low doses (0.005-0.1 mg.L-1), with dose dependence, was able to kill SMMC-7721, SGC-7901 and HeLa cells. IC50 values for SMMC-7721, SGC-7901 and HeLa cells were 0.007, 0.011 and 0.018 mg.L-1 by trypan blue dye exclusion test and 0.016, 0.055 and 0.078 mg.L-1 by neutral red vital staining test. TS inhibited the clonal forming rate of SMMC-7721 and SGC-7901 significantly with IC50 values of 0.021 and 0.036 mg.L-1, respectively. Only when the cells were continuously treated with TS for more than 8 hours, the drug-induced cell lethality could be displayed and strengthened quickly. The growth of tumor cells was notably inhibited after they were exposed to 0.1 microgram/ml of TS for 12 hours. All the experimental results of antitumor activity in vitro showed that SMMC-7721 was most sensitive to TS among the three kinds of tumor cells. CONCLUSIONS: TS has cytotoxic action on tumor cells cultured in vitro and this lethal effect must have an action process, in which tumor cells are not dead but suffer from deadly injury and lost the capability of unlimited proliferation.

Adenocarcinoma↗
PubMed1989

Calcium ion involvement in the action of Pasteurella haemolytica leukotoxin.

The influence of Ca2+ ions on the cytotoxic activity of Pasteurella haemolytica leukotoxin was investigated. The divalent cation influenced the cytotoxic effect of the leukotoxin for sensitive BL-3 target cells, but its absence did not eliminate cytotoxicity. In short-term 1-h assays using neutral red uptake as a measure of cell viability, depletion of Ca2+ either by exhaustive dialysis or by addition of the Ca2+ chelators EDTA and EGTA eliminated the cytolytic effect of low doses of the toxin. Addition of Ca2+ to target cell cultures depleted of the divalent cation restored the cytolytic effect of the leukotoxin. Prolonged exposure of the BL-3 cells to the toxin abrogated the protective effect of EDTA and EGTA. Cell death measured by uptake of neutral red, exclusion of trypan blue and 51Cr release indicated that protection observed in the absence of free Ca2+ was temporary. Toxin-induced cytolysis equivalent to that observed in the presence of Ca2+ occurred following the initial 2-h exposure. In addition, verapamil, a Ca2+ channel blocker, prevented cell death during 1-h cytotoxicity assays. The protection afforded by verapamil was dose-dependent and was influenced by the concentration of Ca2+ in the buffer medium. The results suggest that Ca2+ positively influences the rapid initial phase of cell death resulting from exposure to the toxin, but is not required for the entirety of the cytolytic process.

Animals↗
PubMed1989

Improved colorimetric assay for detecting influenza B virus neutralizing antibody responses to vaccination and infection.

An automated neutralization test for influenza B virus is described in which antibody titers are determined according to the release of neutral red from infected or uninfected cells of the Madin-Darby canine kidney line. Endpoints are determined in a standard enzyme-linked immunosorbent assay reader. The test requires no expensive immunologic reagents and was used to evaluate responses to both vaccination and natural infection against influenza B virus. Overall responses to vaccination were comparable with those obtained by hemagglutination inhibition, using Tween-ether-split influenza B/Ann Arbor/1/86 virus as the antigen (the HI-TE test). The sensitivities of neutralization responses compared with those obtained by the HI-TE test for two vaccines were 88 and 89%; the specificities were lower at 61 and 60%, respectively. Responses to vaccination, measured by hemagglutination inhibition, were significantly higher with split virus compared with whole virus. However, seroconversion by both the HI-TE and neutralization tests was observed in 5 of 10 individuals from whom virus was detected by either culture of nasal or throat washings or the presence of antigen from immunofluorescence in cells from nasal washings.

Animals↗
PubMed1975

Intracellular supravital stain delocalization as an assay for antibody-dependent complement-mediated cell damage.

The ability of hamster SV40 tumor cells to concentrate Neutral Red into localized intracytoplasmic vacuoles and granules has been correlated with the ability of those cells to adhere and to replicate in tissue culture. Cells damaged by complement-fixing anti-tumor antibody and metabolic inhibitors first undergo delocalization of the dye, which appears as a diffuse stain throughout the nucleus and cytoplasm. More severely damaged cells lose the stain entirely, at a stage of progressive cell damage correlated with Trypan Blue uptake. A rapid and sensitive cytotoxic assay procedure has been based upon Neutral Red staining behavior, and the assay has been used to study antibody-dependent, complement-mediated cytotoxic anti-SV40 tumor activity in the sera of normal hamsters.

Animals↗
PubMed1991

Effects of the prolyl 4-hydroxylase proinhibitor HOE 077 on human and rat hepatocytes in primary culture.

Alterations in extracellular matrix occur in many chronic liver diseases leading to the formation of hepatic fibrosis. We have studied the effects of the putative hepatoselective fibrosuppressive compound HOE 077, a proinhibitor of prolyl 4-hydroxylase, on normal adult human and rat hepatocytes in primary culture. In human hepatocyte cultures, the cytotoxicity of HOE 077 was assessed after a 20-h treatment at concentrations ranging from 0.125 to 2 mg/ml of medium. No significant change was found in cell morphology, neutral red uptake, red oil staining, lactate dehydrogenase release, tetrazolium salt reduction, ethoxyresorufin O-deethylase activity and protein synthesis; however, HOE 077 slightly decreased DNA synthesis at 2 mg/ml. In rat hepatocyte cultures, the cytotoxicity of the compound was assessed by testing the same parameters after a daily exposure of cultures for 2 days or 4 days, at concentrations ranging from 0.25 to 4.5 mg/ml of medium. Whatever the concentration, the compound had no obvious morphological effect. However, hepatocytes were less spread at the concentration of 4.5 mg/ml. HOE 077 at 2 mg/ml slightly decreased neutral red uptake but was without obvious effect on protein synthesis after 2 days. By contrast, on day 4, protein synthesis was markedly reduced in hepatocyte cultures exposed to HOE 077 at 4.5 mg/ml. Hydroxyproline content determination in media from 4-day-old hepatocyte cultures incubated with HOE 077 at 0.5 to 4.5 mg/ml, showed a dose-dependent decrease in the hydroxyproline/proline ratio in acetic acid soluble material. By indirect immunoperoxidase, intracellular collagen IV was found to be inhibited in hepatocyte cultures after 4 days of exposure to 4.5 mg/ml HOE 077.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Procaine-induced enhancement of fluid-phase endocytosis and inhibition of exocytosis in human skin fibroblasts.

Local anaesthetics are often applied directly onto the skin, and for this reason the effect of some local anaesthetics upon morphology and cytoskeleton organisation in human skin fibroblasts was investigated. In this paper the authors report that procaine (p-aminobenzoic acid diethylamino-etyl ester hydrochloride) induced vacuolisation of cytoplasm and great enhancement of neutral red accumulation in human skin fibroblasts cultured in vitro. Procaine-induced vacuolisation of cell's cytoplasm was observed to be associated with the enhanced uptake and inhibited release of fluid taken by endocytosis. All these effects appeared fully reversible. The cell vacuolisation cannot be prevented by 3-methyadenine, brefeldine A, and cytochalasine D. On the other hand, nocodazole and caffeine prevent cytoplasm vacuolisation induced by procaine. These observations suggest that procaine-induced formation of great vacuoles is due to an impairment of membrane traffic between endosomes. The authors' results also demonstrate that neutral red uptake assay, if used as a cell viability test, must be interpreted with great caution.

Cells, Cultured↗
PubMed1992

The effect of anabolic-androgenic steroids on primary myocardial cell cultures.

Although recent case reports suggest that anabolic-androgenic steroids may be directly injurious to the cardiovascular system, the direct myocardial cellular consequences of abuse of these drugs are not known. Therefore, the purpose of this study was to describe the concentration- and time-dependent effects of testosterone cypionate (TC), stanozolol (S), and fluoxymesterone (F) on primary myocardial cell cultures. Evaluation of drug effects were made in 4-d-old primary myocardial cell cultures obtained from 3- to 5-d-old Sprague-Dawley rats. The cultures were exposed to 1 x 10(-4) M, 1 x 10(-6) M, and 1 x 10(-8) M concentrations of TC, S, and F each for 1, 4, and 24 h. Cellular injury was evaluated by alterations in beating activity, induction of morphological alterations, lactate dehydrogenase (LDH) release, neutral red retention, and tetrazolium (MTT) formazan production. Significant alterations in beating activity were observed in the 1 x 10(-4) M TC group in which no beating activity was seen at 1, 4, and 24 h. Morphological integrity was disrupted for the 1 x 10(-4) M TC group at 24 h where destruction of the monolayer was observed. Unlike the cultures treated with the three concentrations of both S and F, significant LDH release was seen at 4 and 24 h with those cultures exposed to 1 x 10(-4) M TC. In the evaluation of neutral red retention, 1 x 10(-4) M TC at 24 h showed a significant decrease in ability to retain the dye.(ABSTRACT TRUNCATED AT 250 WORDS)

Anabolic Agents↗
PubMed2004

Trophic transfer and in vivo immunotoxicological effects of tributyltin (TBT) in polar seastar Leptasterias polaris.

This study investigated the potential in vivo immunotoxic effects of tributyltin (TBT) on amoebocytes of 6-armed seastar Leptasterias polaris. Tested animals were contaminated by trophic transfer via alive contaminated prey consisting of blue mussels (3microg TBT g(-1) wet weight (WW) tissue) exposed to seawater containing dissolved TBT. Four biomarkers of immunotoxicological effects were monitored over 45 days at different sampling times (9, 24, 48 and 72h, 11, 18, 25, 32 and 45 days): amoebocytes count (AC), cell viability using Trypan blue exclusion test, phagocytic activity (PA) using a suspension of dead bacteria labelled with fluorescein isothiocyanate (FITC) and injected directly in the coelomic fluid of the animals, and lysosomal integrity (LI) using the neutral red (NR) retention test. Data showed that TBT and its metabolites (DBT and MBT) bioaccumulated preferentially in pyloric caeca, whereas gonads contained only small quantities. Despite the differences in exposure periods to the contaminated diet and in burdens of butyltins (BTs) ingested by the various contaminated groups, there were no significant differences in body burdens of BTs. Only 6.2+/-2.0% of total ingested BTs were retained in soft tissues of seastars. Even if butyltins were not detected in the coelomic fluid (CF), their detrimental effects have been detected in the phagocytic activity of amoebocytes and their lysosomal retention of neutral red, but no effects were observed on amoebocytes count and their viability. These results show that seastar L. polaris possesses adequate mechanisms to depurate ingested TBT without supporting major disturbances of its immune defence system. By their ability to digest whole contaminated prey and eliminate only dissolved metabolites, L. polaris and other seastars with the same preying mode could play a role of "recycling organisms" in coastal environments where toxicants, such as butyltins and other metallic species are accumulated by bivalves and particularly blue mussels.

Animals↗
PubMed2004

Massive cell vacuolization induced by organic amines such as procainamide.

Procaine and some other basic drugs reportedly induce vacuolization of various cell types. We addressed the concentration-effect and structure-activity relationships as well as the mechanism of this effect using three cell lines. Massive vacuolization occurs over several hours in primary cultures of rabbit pulmonary artery smooth muscle cells (SMCs) and COS-1 cells in response to procaine and loosely related amine compounds (procainamide, N-acetyl-procainamide, metoclopramide, lidocaine, triethylamine, nicotine) used at 2.5 mM. Furthermore, chloroquine, propranolol, diphenhydramine, and neutral red are active in this respect at 100 to 250 microM in SMCs and COS-1 cells. Human embryonic kidney 293 cells mildly responded to triethylamine, nicotine, and propranolol only. Tetraethylammonium was uniformly inactive, as well as many other drugs in all three cell types (concentrations up to 2.5 mM). Procainamide does not induce apoptosis in SMCs treated for up to 48 h, although the vacuolization is sustained and proliferation and migration are reduced during this period. Procainamide-induced vacuolization is reversible on drug washing, largely prevented by bafilomycin A1 cotreatment, and has a tentatively identified Golgi origin (uptake of ceramide-C5). Procainamide and neutral red are concentrated in SMCs in a bafilomycin A1-sensitive manner. The preventive effect of bafilomycin A1 suggests that the vacuoles originate from the osmotic swelling of acidic organelles in which the charged basic drugs are trapped at low pH. Drug transport at the plasma membrane may be limiting for this type of response, as suggested by the cell type selectivity of agents and the inhibitory effect of some drugs such as quinidine.

Animals↗
PubMed2005

Serum deprivation induces apoptotic cell death of transformed rat retinal ganglion cells via mitochondrial signaling pathways.

PURPOSE: Apoptosis-related signaling pathways were investigated in a cultured rat retinal ganglion cell (RGC-5) line deprived of growth factors after serum withdrawal from the culture medium. METHODS: RGC-5 cells were subjected to serum deprivation for 2 to 6 days and compared with RGC-5 cells cultured in growth medium containing 10% fetal calf serum. Cell viability was determined by a neutral red dye uptake assay. Apoptosis of RGC-5 cells was established by DNA laddering. The expression of various apoptosis-related genes was investigated by immunoblot analysis, and or reverse transcription polymerase chain reaction (RT-PCR) analysis. The redox state of the cell was determined by biochemical methods, including NF-kappaB binding activity by electrophoretic mobility gel shift assays (EMSA) and mitochondrial damage by JC-1 (5,5', 6,6'-tetrachloro 1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide) staining, using live cell confocal microscopy and cytosolic release of cytochrome c. RESULTS: Fifty percent cell loss was evident after 2 days of serum deprivation, as demonstrated by neutral red dye uptake assay. This cell loss was due to apoptotic cell death, as established by DNA laddering. The oxidative state of serum-deprived RGC-5 cells was perturbed as suggested by the increase in malonyldialdehyde (MDA) and a decrease in reduced glutathione (GSH) levels in cell lysates. The apoptosis of the RGC-5 cells was associated with the activation of caspase-3, -8, and -9, and increased levels of Bax with corresponding decreases in Bcl-2 levels and NF-kappaB (NF-kappaB) binding activity. Serum deprivation was also associated with a loss of mitochondrial function, as revealed by cytosolic release of cytochrome c and JC-1 staining of mitochondria of dying RGC-5 cells. CONCLUSIONS: Taken together, these results indicate that serum withdrawal induces apoptotic cell death in RGC-5 cells via mitochondrial pathways. These studies lead to the speculation that growth factor deprivation arising from blockade of retrograde transport of neurotrophins may involve similar mechanism(s) of retinal ganglion cell death in glaucoma.

Animals↗
PubMed2000

The role of algae (Isochrysis galbana) enrichment on the bioaccumulation of benzo[a]pyrene and its effects on the blue mussel Mytilus edulis.

The role of algal concentration in the transfer of organic contaminants in a food chain has been studied using the ubiquitous model polycyclic aromatic hydrocarbon benzo[a]pyrene (BaP) as the contaminant, Isochrysis galbana as the phytoplankton food source, and the common mussel (Mytilus edulis) as the primary consumer. The effect of algal concentration on BaP uptake by M. edulis was determined by feeding M. edulis daily with I. galbana which had previously been kept in the presence of BaP for 24 h. Four combinations of concentrations of algae and BaP were used to give final exposure concentrations of 30,000 or 150,000 algal cells ml(-1) in combination with either 2 or 50 microg BaP l(-1). BaP concentrations were determined fluorometrically in rest tissues (excluding digestive glands) and digestive gland microsomal fractions of M. edulis after 1, 7 and 15 days exposure, and also in isolated algae. Potentially toxic effects of BaP on M. edulis were examined in terms of blood cell lysosomal membrane damage (neutral red dye retention assay) and induction of digestive gland microsomal mixed-function oxygenase (MFO) parameters [BaP hydroxylase (BPH) and NADPH-cytochrome c (P450) reductase activities]. BaP bioaccumulation in rest tissues (and to a lesser extent in digestive gland microsomes) of M. edulis increased with both increasing BaP and algal exposure concentrations, and over time, producing maximal bioconcentration factors in rest tissues after 15 days exposure to 150,000 algal cells ml(-1) and 50 microg BaP l(-1) of 250,000. The five-fold higher concentration of algae increased BaP bioaccumulation by a factor of approximately 2 for 50 microg BaP l(-1) at day 15. Blood cell neutral red dye retention time decreased linearly with increasing log(10) tissue BaP body burden, indicating an increased biological impact on M. edulis with increasing BaP exposure possibly due to a direct effect of BaP on blood cell lysosomal membrane integrity. An increase was seen in NADPH-cytochrome c reductase activity, and indicated in BPH activity, with 1 but not 7 or 15 days exposure to BaP, indicating a transient response of the digestive gland microsomal MFO system to BaP exposure.

Journal Article↗
PubMed2002

Uptake and effects of the cypermethrin-containing sea lice treatment Excis in the marine mussel, Mytilus edulis.

Wild and farmed mussels, Mytilus edulis, coexist with salmon farms in Scottish sea lochs. A synthetic pyrethroid, cypermethrin, is licensed for use on fish farms to control sea lice infestations as a formulation called Excis. In this study, uptake of cypermethrin from Excis exposure is investigated through the use of gas chromatography with mass-spectrometry. The effects of Excis on mussels are also examined by measuring the neutral red retention time of lysosomes, aerial survival and shell closure. The isomeric ratios of cis:trans cypermethrin measured in mussels are around 80:20; a marked increase from 40:60 to which the mussels were exposed. This is most likely due to preferential metabolism of trans-isomers, as the same response is seen in vertebrates. There is a pronounced behavioural effect of shell closure, where mussels exposed to 1000 microg/l cypermethrin shut their shells within an hour of exposure. Arguments are presented for this effect being either a voluntary response on recognition of cypermethrin, or an effect arising from an involuntary action of cypermethrin on the adductor muscle. Even at 1000 microg/l cypermethrin, neutral red retention time and aerial survival are not affected. The data suggest that the responses of mussels shown here are unlikely to occur in the field, even at the concentrations of cypermethrin used in fish cages, for the treatment of sea lice.

Animals↗