Mortality patterns in trout (Salmo trutta and S. gairdneri) exposed to an anionic detergent in relation to concentration and mechanisms of toxic action

SUMMARY. Histological and electron microscopical study of the gills of fish poisoned by the anionic detergent sodium lauryl sulphate indicates that the nature of the toxic action changes at a concentration of about 120 mg I⁻¹. Toxicity tests were conducted to determine whether this change could be detected in the test data, using brown trout ( Salmo trutta ) and rainbow trout ( S. gairdneri ).
Toxicity curves showed no indication of the change in toxic action, but at concentrations of 120 and 130 mg I⁻¹ of sodium lauryl sulphate 'split' probit lines occurred, and the lines for 150 mg I⁻¹ consistently differed in slope from other lines.     

A histological study of the response of the interrenal cells of the goldfish (Carassius auratus) to treatment with sodium lauryl sulphate

Treatment of goldfish ( Carassius auratus ) with sub-lethal concentrations of an anionic detergent sodium lauryl sulphate for 1, 2 or 4 weeks produced histological changes in the interrenal (steroidogenic) cells of the head kidney which are indicative of a cellular activation. Significant increases in both the nuclear diameter of these cells and the number of nucleoli contained in the nuclei occurred after 1 week's treatment, although these effects were more pronounced after 2 and 4 weeks. There were little associated alterations in chromaffin cell activity. Preliminary experiments with another pollutant, zinc sulphate, suggest that it exerts a similar action to sodium lauryl sulphate on the interrenal cells. It is suggested the increases in corticosteroid production which occur after exposure of fish to sub-lethal concentrations of pollutants may be important in the development of a generalized disease syndrome and to the long-term success of fish populations.     

Mechanisms of the protective action of cryoprotectors on Escherichia coli cells

Two classes of cryoprotectors, namely, glycerol (penetrating the cell) and dextran with a mol. mass of 15-20,000 Da (non-penetrating the cell), were tested for their ability to exert a protective effect on the permeability and viability of Escherichia coli M 17 cells subjected to different freezing conditions. Cell permeability assayed in terms of the release of low-molecular-weight compounds into the surrounding medium was shown to be disordered to a far less extent when dextran was used as a cryoprotective agent than in the case of glycerol. The cells were found to be resistant to lysis stimulated by the detergent sodium lauryl sulfate (0.02%) in the presence of dextran. The cells were still capable of forming colonies after their freezing to -10 degrees C in the presence of the cryoprotectors in media containing the detergent (2%). Once the cells had been frozen to -196 degrees C, only those protected by glycerol were resistant to the detergent in the growth medium. Different mechanisms of the cryoprotective action on E. coli cells are discussed.     

Absence of Chromosome Damage in the bone marrow of rats fed detergent actives for 90 days

Four detergent actives, sodium lauryl sulphate, DOBS 055, Dobanol 25 sulphate LCU and Dobanol 25 sulphate HCB, were fed to rats in the diet for 90 days at the maximum tolerated dose, 1.13 percent active ingredient in each case. Sodium lauryl sulphate and DOBS 055 were also fed at half this concentration. Chromosome preparations were made from the bone marrow and scored for the presence of rearrangements, chromatid gaps and breaks and isochromatid gaps and breaks. The four detergent actives were found to have no effect on the chromosomes of rat bone marrow cells.     

Low sensitivity of ciliary activity in the gills of Anodonta cygnea to some ecotoxicals

1. The effects of some ecotoxical model substances on the activity of frontal gill cilia of freshwater mussel Anodonta cygnea were studied in 1 and 24 hr experiments with the particle transport method. The effects were compared with the results of standard Daphnia magna ec₅₀ tests with the same substances.2. Variations of pH between 4.8 and 8.1 affected the ciliary activity by less than 30%.3. Ciliary activity was less sensitive to heavy metal salts, sodium lauryl sulphate and to two pulp industry waste model substances than D. magna.4. Compared to D. magna, the ciliary activity was more sensitive to formalin and 2,4-dinitrophenol, and as sensitive to ethanol.5. Ciliary activity in bivalve gills is a well regulated and/or a relative insensitive function, but it may be used as a rapid screening test for some cell ecotoxicals.     

An improved method for the extraction of prostaglandins

Present methods of extracting prostagalndins (PGs) give poor recoveries from synovial fluid, probably because the PGs bind to protein and are lost in the precipitation stage of extraction. Addition of the nonpolar detergent sodium lauryl sulphate prior to extraction improves recovery of PGs. It is suggested that sodium lauryl sulphate competes with PGs for the binding sites.     

Uptake of cadmium through isolated perfused gills of the Chinese mitten crab, Eriocheir sinensis

Using the perfusion method, we compared cadmium accumulation and influx across the gills of the euryhaline Chinese mitten crab Eriocheir sinensis, exposed to 4.8 microM cadmium in the incubation medium (OUT). Cadmium influx was not observed across posterior gills while it ranged from 0.15 to 6.82 nmol Cd g(-1) gill w.w. h(-1) across anterior ones. For these respiratory gills, a strong increase (40 times) was observed when calcium was removed in both incubation and perfusion media while the lack of sodium in the perfusion medium resulted in a 46 times decrease. For crabs acclimated 15 days to artificial seawater, cadmium influx across anterior gills showed a 21 times decrease when compared with freshwater acclimated ones. On the other hand, after 3 h of perfusion, we detected cadmium accumulation in both types of gills, ranging from 3.8 to 68 nmol Cd g(-1) gill w.w. in anterior gills and from 2.1 to 39 nmol Cd g(-1) gill w.w. in posterior ones. Such accumulations represent between 61.3 and 100% of the total uptake of cadmium through the gills. From these results, we suggest that cadmium can penetrate more easily into the hemolymph space through the 'respiratory' type epithelium present in the anterior gills but absent in the posterior ones. This metal uptake is likely to occur at least in part through the same pathways as calcium. On the contrary, cadmium seems to be sequestered inside the posterior gills, perhaps in the cuticle of the salt-transporting type epithelium.     

Cytological effects of experimental exposure to Hg on the gill epithelium of the European flat oyster Ostrea edulis: ultrastructural and quantitative changes related to bioaccumulation

The significance of ultrastructural changes in the gill epithelial cells as a parameter of detection of Hg exposure in the flat oyster, Ostrea edulis, was tested by a 34-day exposure to 5 microg l(-1) of Hg. The concentration of Hg (38.76 microg g(-1) dry weight) in gill tissue was maximal after 25 days and then decreased. The histological pattern of gill filaments in control samples did not vary throughout the experiment, except for the volume of mucocytes after 4 days of exposure, as an adaptation to experimental conditions. This volume increased significantly and then decreased according to the accumulation of Hg in the gills. After 18 days, absorptive and ciliated cells of the gill epithelium showed blebs in microvilli membranes, discocilia and swollen mitochondrial cristae. Both cell types showed distinct cellular lysis stages after 25 days of exposure. These are the target cells of Hg and other metals and the reported hypertrophy of mucocytes increase occurs in response to pollution by Hg, which could contribute to the detoxification process.     

Treatment of Cells with Detergent Activates Caspases and Induces Apoptotic Cell Death

Due to their amphiphilic properties, detergents readily disrupt cellular membranes and cause rapid cytolysis. In this study we demonstrate that treatment of cells with sublytic concentrations of detergents such as Triton X-100, Nonidet P-40, n-octylglucoside and the bile salt sodium deoxycholate induce typical signs of apoptosis including DNA fragmentation and cleavage of poly(ADP-ribose) polymerase molecules. The detergent concentration required for apoptosis was below the critical micellar concentration. Induction of apoptosis was not restricted to human cells but similarly occurred in a variety of other vertebrate cell lines. Unstimulated peripheral blood mononuclear cells were susceptible to apoptosis induction by detergent suggesting that apoptosis in this circumstance is not mediated by CD95. Cell death was not due to influx of calcium from the medium. Apoptosis was blocked and cytolysis prevented by treatment with peptide inhibitors of caspases. These findings suggest a process of apoptosis that is initiated upon nonspecific alterations at the cell membrane level. Physiologic correlates of this process still have to be defined. Received: 12 November 1999/Revised: 6 March 2000     

Autocides produced by Myxococcus xanthus.

Ethanol extracts of Myxococcus xanthus contained several substances, referred to as autocides, which were bactericidal to the producing strain but showed no activity against other bacteria. The autocides were produced by growing cells and remained largely cell bound throughout the growth cycle; ca. 5% of the autocidal activity was found in the supernatant fluid at the time cell lysis began. The autocides were separated by sequential-column and thin-layer chromatography into five active fractions (AM I through AM V). Each of the fractions was at least 20 times more active against M. xanthus than against the other gram-negative or gram-positive bacteria tested. AM I, AM IV, and AM V were inactive against yeasts, whereas a mixture of fractions AM II and AM III was active against Rhodotorula sp. At low concentrations, AM I reversibly inhibited the growth of M. xanthus; at higher concentrations of AM I, the cells lysed within 1 h. The lowest concentration of AM IV that showed any activity caused rapid cell death and lysis. The mode of action of the major autocide, AM V, was different from that of AM I and AM IV. During the initial 2 h of treatment, the viable count of M. xanthus cells remained constant; during the next few hours killing occurred without lysis; within 24 h lysis was complete. The autocidal activity of each of the fractions was expressed when the cells were suspended in buffer, as well as in growth medium. The possible role of autocides in developmental lysis of M. xanthus is discussed.     

Growth inhibition of leukemia cell line CEM-C1 by farnesol: effects of phosphatidylcholine and diacylglycerol.

Acute leukemia cells of the established line CEM-C1 were treated during growth in serum-free medium with various concentrations of trans-trans farnesol. At concentrations ranging from 9.0 to 31.5 microM, farnesol inhibited growth of these cells without causing cell lysis. This effect was preceded by very rapid inhibition of choline incorporation in cellular lipid fraction. The growth inhibitory effect was prevented to a large extent by incubation with phosphatidylcholine or diacylglycerol.     

The effect of bile, bile acids and detergents on calcium absorption in the chick

1. Bile from rachitic or normal chicks causes an immediate increase in the intestinal absorption of soluble calcium in rachitic and vitamin D(3)-treated chicks as tested in vivo by intestinal-loop and oral-dosing methods. 2. This effect is apparently solely due to the taurine-conjugated bile acids present in the bile and is independent of the action of vitamin D. 3. Chick bile and bile acids can increase the solubility and the absorption of calcium presented as sparingly soluble calcium hydrogen phosphate. 4. In addition, bile is necessary to some extent at least for the intestinal absorption of vitamin D(3) in the chick and this would indirectly enhance the absorption of calcium. 5. Thus bile is capable of a threefold action in the absorption of calcium in the chick. It is suggested that the direct action on sparingly soluble forms of calcium is of considerable physiological importance since most of the calcium in the normal bird's diet would be in this form. 6. Bile acids enhance the absorption of calcium in all regions of the small intestine of the chick. 7. Of a range of bile acids and detergents tested for enhancement of calcium absorption, various taurine-conjugated bile acids and sodium lauryl sulphate, an anionic detergent, are effective. A non-ionic detergent (Tween 80) and a cationic detergent (Zephiran) are without effect. 8. The ability of a substance to increase directly the intestinal absorption of soluble calcium appears to depend to some extent on an anionic detergent action, i.e. the ability to form a salt or complex soluble to some extent in both aqueous and lipid phases. 9. In chicks the immediate deposition of calcium ((45)Ca) in the bones closely reflects any increase in plasma calcium radioactivity regardless of the cause of the increase and regardless of the vitamin D(3) status. Although sodium lauryl sulphate can increase markedly the calcium absorption from the gut and the immediate deposition in the bones it has no significant effect on rickets. 10. Some of the implications of these findings are discussed.     

Molecular organization of pheophytin a in aqueous solutions of detergents

Absorption, fluorescence and excitation fluorescence spectra of pheophytin a have been measured in aqueous solutions of nonionic (Triton X-100), anionic (sodium lauryl sulphate) and cationic (Cetyl pyridinium chloride) detergents at different concentrations and pH after system relaxation. By measuring the second derivative and differential spectra, it has been shown, that if detergent concentrations are lower than critical micelles concentration, or if the detergent is completely absent, the pigment forms conglomerates containing both dimeric and monomeric forms with an efficient energy transfer between them. If detergent concentrations are higher than critical micelles concentration, pheophytin a localizes in detergent micelle in monomeric form at neutral and acidic pH, and allomerizes at alkaline pH. The spectral characteristics of pheophytin a dimers in the conglomerate and its monomers in micelles poorly (if at all) depend on the sign of the detergent molecule charge.     

Ultrastructure and development of the gills in<Emphasis Type="Italic"> Rana dalmatina</Emphasis> (Amphibia,Anura)

The appearance and the modification of the gill apparatus in Rana dalmatina tadpoles have been described in the different phases of larval development. The morphology and ultrastructure have been studied using light microscopy and both scanning and transmission electron microscopy. The organization of the gills during the initial phases of development (external gills or transient gills) brings to mind the characteristics of Urodela larvae in which the gills appear to consist of three tufts of filaments supported by the gill arches III, IV and V. The cellular composition of the transient gills appears to be extremely simple and the presence of specialized cells is not noted. Basal cells, pavement cells and ciliated cells form the thin mono- or bilayered epithelium. In the persistent gills (or internal gills) of the R. dalmatina tadpole (Ortons larval type 4) the gill arches carry four rows of gill tufts branching out to the ventral region. Meanwhile, from the dorsal portion of the arch the gill filters present an axial portion from which there is much branching out, which confers a characteristic appearance on this part of the gills. The cellular composition of the gill tufts and of the filters is different: in the gill tufts basal cells, pavement cells, ciliated cells, cubic cells and mitochondria-rich cells (MRCs) have been recognized, while in the gill filters the last cellular type does not appear. The MRC has highly variable forms and dimensions and is characterized by the presence of numerous mitochondria in the cytoplasm. Often the MRCs manifest themselves grouped together, in groups of three or more. The pavement cells and the cubic cells demonstrate identical ultrastructural characteristics and have an external surface area characterized by the presence of short superficial microridges and numerous vacuoles in the apical cytoplasm.     

Teleost chloride cell. I. Response of pupfish Cyprinodon variegatus gill Na,K-ATPase and chloride cell fine structure to various high salinity environments

Certain euryhaline teleosts can tolerate media of very high salinity, i.e. greater than that of seawater itself. The osmotic gradient across the integument of these fish is very high and the key to their survival appears to be the enhanced ability of the gill to excrete excess NaCl. These fish provide an opportunity to study morphological and biochemical aspects of transepithelial salt secretion under conditions of vastly different transport rates. Since the cellular site of gill salt excretion is believed to be the "chloride cell" of the branchial epithelium and since the enzyme Na,K-ATPase has been implicated in salt transport in this and other secretory tissues, we have focused our attention on the differences in chloride cell structure and gill ATPase activity in the variegated pupfish Cyprinodon variegatus adapted to half-strength seawater (50% SW), seawater (100% SW), or double-stregth seawater (200% SW). The Na,K-ATPase activity in gill homogenates was 1.6 times greater in 100% SW. When 50% SW gills were compared to 100% SW gills, differences in chloride cell morphology were minimal. However, chloride cells from 200% SW displayed a marked hypertrophy and a striking increase in basal-lateral cell surface area. These results suggest that there are correlations among higher levels of osmotic stress, basal-lateral extensions of the cell surface, and the activity of the enzyme Na,K-ATPase.     

Effects of a polyoxyethylene detergent (Brij 58) on platelet aggregation, release and clotting activity

Low concentrations of a polyoxyethylene detergent, Brij 58, inhibited the secondary phase of platelet aggregation induced by ADP in human citrated platelet-rich plasma but had no effect on primary aggregation. Thrombin-induced aggregation of washed human platelets suspended in Tyrode's buffer was inhibited after incubation of cells with 4.10(-6) M detergent. Efflux of [14C]serotonin, 45Ca2+ and labile aorta contracting substance (thromboxane A2) and development of prothrombin-converting activity (platelet factor 3) were abolished concomitantly. Aggregation of washed platelets either by sodium arachidonate or by collagen was also inhibited by the same concentration of Brij 58 which inhibited thrombin aggregation. This concentration did not itself produce any release of a cytoplasmic marker, lactate dehydrogenase, from platelets. Higher concentrations of Brij 58, exceeding 4.10(-5) M, lysed the cells liberating lactate dehydrogenase, serotonin and Ca2+. When albumin was included as a platelet stabilizer in the suspending medium the concentration of detergent required for the inhibitory effects was increased ten-fold. This could be attributed to competitive binding of the detergent to albumin, demonstrated with [14C]acetylated Brij 58. A variety of other polyoxyethylene detergents, at concentrations from 8.10(-4) to 5.10(-3) M, also inhibited platelet aggregation induced by thrombin. It is concluded that low concentrations of Brij 58 stabilize the platelets against the action of aggregating agents, while higher concentrations produce membrane destabilization and cell lysis.     

Gill Na(+), K(+)-ATPase in a series of hyper-regulating gammarid amphipods: enzyme characterisation and the effects of salinity acclimation

The enzyme Na(+), K(+)-ATPase was investigated in the gills of selected hyper-regulating gammarid amphipods. Gill Na(+), K(+)-ATPase was characterised with respect to the main cation and co-factor concentrations for the freshwater amphipod Gammarus pulex. The optimum cation and co-factor concentrations for maximal gill Na(+), K(+)-ATPase activity in G. pulex were 100mM Na(+), 15mM K(+), 15mM Mg(2+) and 5mM ATP, at pH 7.2. The effects of salinity acclimation on gill Na(+), K(+)-ATPase activity and haemolymph sodium concentrations was investigated in selected gammarid amphipods from different salinity environments. Maximal enzyme activity occurred in all gammarids when acclimated to the most dilute media. This maximal activity coincided with the largest sodium gradient between the haemolymph and the external media. As the haemolymph/medium sodium gradient decreased, a concomitant reduction in gill Na(+), K(+)-ATPase activity occurred. This implicates the involvement of gill Na(+), K(+)-ATPase in the active uptake of sodium from dilute media in hyper-regulating gammarids.     

Shear thickening of DNA in SDS lysates.

Cells of Escherichia coli were subjected to lysis by an alkali detergent treatment (sodium dodecyl sulphate). The rate of detergent lysis was not first order. The rheological properties of the lysate were measured using a controlled stress rheometer. Detergent-lysed cells produced a lysate which showed marked non-Newtonian properties. The material showed a shear thickening at specific low shear stress conditions. The acceleration of the cone during the ascent stage of a flow curve, influenced the shape of the flow curves. These findings are discussed in relation to the form of bacterial DNA in solution.     

The use of sodium perchlorate in deproteinization during the preparation of nucleic acids (Short Communication)

Sodium perchlorate in high concentrations will remove from solution the detergent sodium dodecyl sulphate and protein complexed with it. This and the failure of proteins to be precipitated by ethanol from solutions containing a high concentration of sodium perchlorate can be utilized as efficient, rapid and simple deproteinization procedures during the preparation of nucleic acids.     

Capacity of the outer membrane of a gram-negative marine bacterium in the presence of cations to prevent lysis by Triton X-100.

Cells of marine pseudomonad B-16 (ATCC 19855) washed with a solution containing 0.3 M NaCl, 50 mM MgCl2, and 10 mM KCl (complete salts) could be protected from lysis in a hypotonic environment if the suspending medium contained either 20 mM Mg2+, 40 mM Na+, or 300 mM K+. When the outer double-track layer (the outer membrane) of the cell envelope was removed to yield mureinoplasts, the Mg2+, Na+ or K+, requirements to prevent lysis were raised to 80, 210, and 400 mM, respectively. In the presence of 0.1% Triton X-100, 220, 320, and 360 mM Mg2+, Na+ or K+, respectively, prevented lysis of the normal cells. Mureinoplasts and protoplasts, however, lysed instantly in the presence of the detergent at all concentrations of Mg2+, Na+, or K+ tested up to 1.2 M. Thus, the structure of the outer membrane appears to be maintained by appropriate concentrations of Mg2+ or Na+ in a form preventing the penetration of Triton X-100 and thereby protecting the cytoplasmic membrane from dissolution by the detergent. K+ was effective in this capacity with cells washed with complete salts solution but not with cells washed with a solution of NaCl, suggesting that bound Mg2+ was required in the cell wall membrane for K+ to be effective in preventing lysis by the detergent. At high concentrations (1 M) K+ and Mg2+, but not Na+, appeared to destabilize the structure of the outer membrane in the presence of Triton X-100.