Search

Interactions between xenobiotics may induce synergistic or antagonistic biological effects on aquatic vertebrates and invertebrates. These effects have been demonstrated in terms of altered mortality. behavior, physiology, and cellular and subcellular structure. Nevertheless, knowledge of interactions between xenobiotics in aquatic life and their biological consequences is not extensive and large gaps exist. Moreover, in some cases, serious questions can be raised about whether antagonism or synergism was actually demonstrated on the basis of the data presented. Clearly, an expansion of our present understanding of xenobiotic interactions and their biological effects is of critical importance in assesing the impact of xenobiotics on aquatic life.

Field studies were conducted over a 5-year period in Puget Sound to investigate etiological relationships between prevalences of hepatic neoplasms in bottom-dwelling marine fish, with emphasis on English sole (Parophrys vetulus), and concentrations of toxic chemicals in sediments and bottom fish. Statistically significant correlations were found between prevalences of hepatic neoplasms and (1) sediment concentrations of aromatic hydrocarbons, and (2) concentrations of metabolites of aromatic compounds in the bile. A significant difference was also found between the concentrations of N-oxyl derivatives of nitrogen heterocycles (free radicals) in liver microsomes of English sole with liver lesions compared to sole without liver lesions. These N-oxyl free radicals were apparently metabolically derived from complex suites of nitrogen heterocycles present in Puget Sound environments. Recent evidence suggests that aromatic free radicals (possibly derivatives of aromatic hydrocarbons) may also be bound to hepatic DNA isolated from English sole with liver neoplasms collected in several polluted areas of Puget Sound. Such evidence for xenobiotic-DNA interactions has thus far not been obtained for fish from reference areas and for lesion-free fish from polluted areas. Various laboratory studies designed to evaluate the etiology of the liver neoplasms have also yielded evidence that is consistent with the view that high molecular weight aromatic hydrocarbons play a significant role in the etiology of hepatic tumors in the bottom-dwelling fish. Associations between chemical exposures and diseases in other marine species from southern California and Boston Harbor are also discussed. Similar relationships between liver and skin neoplasms in selected bottom feeding fresh water species and sediment-associated chemicals are also presented.

Physical properties (e.g. specific gravity, adiabatic compressibility and sound velocity) of lipids isolated from tissues from contiguous areas of the fatty melon of an echo-locating porpoise (Delphinus delphis) were determined to elucidate relations between lipid composition and structure, and sound transmission in the head. Lipid content varied greatly within the melon (13.6-77.6% of the tissue weight) and triacylglycerols (80-100%) were the major lipid components. This lipid class was composed of diisovaleroylglycerides (triacylglycerols containing two isovaleroyl moieties and a long-chain acyl moiety), monoisovaleroyldiacylglycerols and triacylglycerols consisting of long-chain acids. The lipid-rich (greater than 45%) areas in the melon contained a high proportion (greater than 45% of total triacylglycerols) of diisovaleroylglycerides. There were gradations of sound velocities within the melon; the lowest sound velocities were associated with high concentrations of diisovaleroylglycerides (less than 1400 m/s) and the highest with high concentrations of long-chain triacylglycerols. Assuming an average sound frequency of 75 kHz, and considering dimensions of melon (path length and width of 12-14 cm and 5 cm, respectively), a forward radiating lobe of 15-25 degrees is produced. Thus, the deposition of lipids of different acoustic properties in a three-dimensional matrix within the porpoise melon results in a lens for the projection of sound into the marine environment.

With 63,000 chemicals in common use, the task of identifying specific pollutants and their effects in relation to marine life is immense. The interdisciplinary approach to this complex issue includes studies in analytical chemistry, biochemistry, vertebrate and invertebrate pathology, electron microscopy, immunology, and behavioral biology. Primary concerns are whether pollutants are available to organisms and whether they are transferred through marine food webs. Studies on marine and estuarine pollution in the New York Bight and Puget Sound, Washington, are summarized. Among other results it is interactive effects between two pollutants in marine organism that account for substantial alterations in certain biochemical systems and in cellular morphology. (JGB)

The whole brain of a porpoise (Delphinus delphis) comprised 23.1 wt% of phospholipids on a dry weight basis. Ethanolamine phosphoglycerides (36.6 wt%), choline phosphoglycerides (27.3 wt%), and serine phosphoglycerides (16.9 wt%) were the major components of the phospholipids. A unique feature of the data was the occurrence of large amounts of isovaleric acid in choline phosphoglucerides (28.1 mol%) and ethanolamine phosphoglycerides (6.4 mol%), together with 11.6 and 15.2 mol% of long-chain (C11--C16) iso-acids, respectively. Interestingly, serine phosphoglycerides did not contain detectable amounts of isovaleric acid although trace amounts of long-chain iso-acids were present. No previous evidence exists to show that appreciable amounts of a short-chain acid can be accommodated in animal phospholipids. The occurrence of isovaleric acid in the principal phosphoglycerides of the porpoise brain elicits an interest in how such an anomalous structure is accommodated in the lipid bilayers of the neural membranes.

A number of individual metabolites of aromatic compounds were found in the hydrolyzed bile of five English sole (Parophrys vetulus) captured from polluted sites in Puget Sound, Washington. Metabolites of fluorene, dibenzofuran, phenanthrene, fluoranthene, pyrene and benzo-[a]pyrene (BaP) were tentatively identified by gas chromatography/mass spectrometry (GC/MS) or by high-pressure liquid chromatography (HPLC) with fluorescence detection. Identifications of these metabolites were confirmed by comparing their fluorescence excitation/emission and mass spectra to those obtained from metabolites produced after other English sole from a reference site were injected with individual parent aromatic compounds. High concentrations of many of the individual metabolites quantitated (up to 300,000 ng/g) were found in the hydrolyzed bile of sole sampled from polluted sites. None of these metabolites were found in bile of sole sampled from a relatively clean (reference) site in Puget Sound.

Rac-[1-14C]-palmitylglycerol (chimyl alcohol), rac-[1-14C]-palmityl-2,3-dioleoylglycerol, and rac-palmityl-2,3-[9, 10-3H]-dioleoylglycerol were incubated with dogfish (Squalus acanthias) serum for periods of up to 15.0 hr. The ether bond of the carbon 14 labeled chimyl alcohol was cleaved readily, and radioactivity was incorporated into free fatty acids and the acyl chains of the major glycerolipids of the serum. In sharp contrast, the ether bond of the corresponding dioleoyl derivative remained virtually intact. However, the tritium from the acyl chains was incorporated into glycerolipids via intermolecular rearrangements of fatty acids. The findings are consistent with previous findings with rat liver microsomes showing that the ether linkages of alkylglycerolipids are resistant to oxidative cleavage when acyl groups are present on the glycerol moiety. However, substantial differences may exist between the conditions required for oxidative cleavage of the ether linkage of alkylglycerols in mammals and primative fish.

A 4-year multidisciplinary study was conducted on relationships between pollutants and diseases of fish in Puget Sound, WA. In this study, high concentrations of a large number of anthropogenic chemicals such as petroleum hydrocarbons, polychlorinated biphenyls (PCBs) and other chlorinated compounds, pesticides, and metals were found in certain Puget Sound sediments. For example, over 900 individual organic compounds were detected in sediment from one urban bay (Commencement Bay), and evidence was obtained for the presence of numerous additional compounds. Many of the chemicals accumulated in bottom-dwelling fish, and high levels of certain toxic chemicals in the urban bays were linked to serious diseases (e.g., liver carcinomas) of English sole (Parophrys vetulus) and other demersal fish species. It was concluded that application of the approach used would reveal comparable serious pollution-related health problems in marine biota in other urban coastal areas of the world.

Laboratory studies with individual petroleum components, model mixtures of hydrocarbons, fractions of petroleum, and whole oil have demonstrated, mostly at high exposure concentrations, an association between petroleum and various cellular/subcellular alterations in marine organisms. Recent evidence, notably from studying the effect of the AMOCO CADIZ oil spill, suggest that cellular/subcellular alterations also result from exposing marine organisms to petroleum in the field. In marine environments, however, it is still generally not possible to predict the type or degree of impact of petroleum on organisms because little information is available on the influence of myriad natural and man-induced environmental variables on its fate and effects.Key words: marine invertebrates and teleosts, petroleum, pollution, aromatic hydrocarbons, acute/chronic exposures, cellular/subcellular changes, pathological changes, morphology, mutagenesis, DNA binding, laboratory studies, field studies

Free radicals of xenobiotics in liver microsomes of English sole (Parophrys vetulus) with hepatic neoplasms and other liver lesions were shown to be N-oxyl derivatives of nitrogen heterocycles. The fish were obtained from the highly polluted Duwamish River in Seattle, Washington State. The chemical structures of the free radicals were elucidated primarily by electron paramagnetic resonance (EPR) spectroscopy. Carbazole-9-oxyl was identified and other N-oxyl derivatives of nitrogen heterocycles also appeared to be present. Evidence showing that English sole are capable of forming nitroxyl free radicals from nitrogen heterocycles was obtained when carbazole was administered via injection into the caudal vein: that is, EPR spectroscopy of bile and lyophilized liver microsomes showed the presence of carbazole-9-oxyl. The evidence for the formation of N-oxyl derivatives in the English sole liver is of interest in regard to the etiology of hepatic lesions in fish.

1. 1. Diisovaleroylglycerides were found to be preferentially deposited in a discrete region (acoustic window) of the external mandibular tissue of the porpoise (Tursiops tmncatus), through which sound waves arc directed to the interior mandibular waveguide. The diisovaleroylglycerides may play a significant role in modifying the properties of sound received from the aquatic environment. 2. 2. Mass spectral analyses revealed that the diisovaleroylglycerides from the acoustic tissues arc almost exclusively the 1,3-isomers. 3. 3. The previously reported active mctabolismof the isovaleroyl chains in the diisovaleroyl glycerides of acoustic tissues is discussed in relation to the occurrence of essentially a single isomeric form.

The major lipids of the dogfish (Squalusacanthias) are the diacyl glyceryl ethers and triglycerides. These classes of compounds in the flesh (dorsal section) and liver were separated by thin-layer chromatography. The glyceryl ethers and/or fatty acids resulting from saponification of each of these fractions were analyzed by gas–liquid chromatography as their isopropylidene and methyl ester derivatives, respectively. Few significant differences were apparent between the ether portions of the diacyl glyceryl ethers of the flesh and liver, but the fatty acids were quite different in composition. Those of the flesh contained high percentages of the C20 and C22 polyenoic acids that are characteristic of most fish lipids; those of the liver contained little polyenoic acid but high concentrations of C20 and C22 monoenoic acids. Although the triglycerides of the flesh contained more of the polyenoic acids than the liver, the differences in this fraction between the flesh and liver were less striking. It appears that the over-all unsaturation of the dogfish lipids is largely governed by the relative amounts of monoenoic and polyenoic acids in the C20 and C22 series.

The molecular structures of 1-alkyl-2,3-diacyl glycerols from the liver of dogfish (Squalus acanthias) revealed an accumulation of C20 and C22 polyenoic acids on position 2 that is characteristic of marine glycerolipids. The presence of these acids on position 2 may imply biosynthesis from exogenous 2-acyl glycerols. However, data on incorporation of radioactivity from [1-14C]palmitic acid, which revealed extensive metabolism of acyl groups on position 2, argues against such a pathway. The structural data can be ruled out by the metabolic data, except for the possibility of a small degree of biosynthesis of 1-alkyl-2,3-diacyl glycerols from a discrete pool of 2-acyl glycerols.

By molecular distillation of oxidized cod liver oil a partial isolation of the lipid species responsible for the diet-induced generalized Shwartzman reaction in pregnant rats has been achieved. Molecular distillation produced three fractions and a residue. Qualitative and quantitative differences in each fraction were shown by determining iodine and saponification numbers and by thin layer chromatography on silicic acid. The incidence of the Shwartzman reaction was higher with fraction III than with either of the other two fractions, the residue, or the original oxidized cod liver oil. It is evident that the toxic factor or factors can be concentrated by molecular distillation. The high temperatures used in the molecular distillation destroy peroxides in the lipids. Therefore, in spite of the fact that oxidation of dietary fats is necessary to produce the reaction, peroxides in the dietary lipid are not necessary for the development of the tissue reaction. The residue fraction contains high molecular weight polymers and the incidence of the Shwartzman reaction is low in animals fed this material. It is unlikely that high molecular weight polymers are responsible for the tissue reaction. Animals that do not gain weight at a rate close to that of the normal pregnant rat do not develop the reaction. Conversion of fraction III into its ethyl esters increased the incidence of the Shwartzman reaction in two experiments. Esterification appears to "unmask" a certain amount of the active factor. The specific lipid material or materials responsible for the development of the generalized Shwartzman reaction remains to be found.

1. 1. Acyl moieties of triacyl glycerols and wax esters from acoustic (mandibular canal and melon) and blubber tissues of the porpoise ( Tursiops gilli ) were compared to investigate the possible role of lipid structures in bio-acoustics. Similar comparisons were made of alcohol moieties derived from wax esters. 2. 2. Acyl moieties of triacyl glycerols from the mandibular canal, melon and blubber contained 43.0 mole %, 50.5 mole % and 8.7 mole % of isovaleric acid, and 20.4 mole %, 21.5 mole % and 3.2 mole % saturated long-chain iso acids, respectively. 3. 3. Acyl moieties of wax esters from the mandibular canal, melon and blubber contained 43.6 mole %, 58.4 mole % and 18.9 mole % isovaleric acid, and 17.5 mole %, 21.0 mole % and 10.5 mole % saturated long-chain iso acids. The alcohols of wax esters from the mandibular canal, melon and blubber comprised 47.5 mole %, 61.4 mole % and 18.8 mole % saturated iso alcohols, respectively. Wax esters from acoustic tissues contained 2–3 mole % isopentanol. This alcohol was not detected in wax esters from blubber. 4. 4. Triacyl glycerols and wax esters from the blubber contained relatively high percentages of straight-chain unsaturated acids and alcohols. 5. 5. The data reveal that acoustic tissues deposit saturated branched acids and alcohols at the expense of straight-chain unsaturated acids and alcohols common to most terrestrial and aquatic species.

The glycerolysis reaction was applied to menhaden, tuna, herring, sardine, and salmon-egg oils. Optimum reaction time for the preparation of α-monoglycerides was found to vary, reproducibly, from 45 to 60 min., depending on the particular kind of marine oil employed. The method was suitable for the preparation of kilogram quantities. A laboratory method for the prepagation of kilogram quantities of highly pure acetylated α-mono-glycerides was developed. Both the glycerolysis mixtures from marine oils and their acetylated products were light in color and substantially free of odor. Thin-layer silicic acid chromatography, as described here, was found suitable for the analysis of acetoglycerides from marine oils. The work indicated that the method may have wide use for the separation and identification of other lipid classes as well.

High denisty lipoproteins from the serum of salmon (Oncorhynchus kisutch), containing a maleimide spin label (4-male-imido-2,2,6,6-tetramethylpiperidinooxyl), were exposed to HgCl2, CdCl2, and CH3HgCl under physiological conditions. Electron spin resonance spectrometry revealed that HgCl2 and CdCl2 produce significant alterations at sites representing weakly and strongly immobilized label. The observed changes appear to be taking place primarily in the surface architecture. No alterations were found in the normal spectra of high density lipoproteins exposed to CH3HgCl under similar conditions. Each metal species binds strongly with the apo-high density lipoproteins; however, marked differences exist in the effects produced upon high density lipoprotein structure by the inorganic ions and CH3HgCl.

Adsorption chromatography on thin layers of silicic acid or alumina provides a new and highly efficient analytical tool for the rapid separation of lipids according to classes of compounds.

More than two-thirds of the triacylglycerols from the acoustic tissues of the porpoise (Tursiops gilli) consist of 2 moles of isovaleric acid for every 1 mole of long-chain acids. Cranial blubber, which has no distinct acoustic function, does not contain these unusual glycerides. The presence of large amounts of diisovaleroylisopentadecanoylglycerol suggests that this structure may be particularly important in sound transmission through lipid-protein matrices.

Further work has been done on the application of thin-layer adsorption chromatography to the fractionation of complex lipid mixtures into classes.

The preparation of linolenaldehyde and of mixed aldehydes from highly unsaturated sources, such as menhaden oilvia the acyloin condensation, is described. Reduction of the acyloins and subsequent cleavage of the glycols gave over-all yields of 85 to 90% free aldehydes.

High prevalences of idiopathic hepatic lesions, including neoplasms (e.g., hepatocellular carcinomas, cholangiocellular carcinomas) (27%, 20 of 75 fish) and foci of cellular alteration (putative preneoplastic lesions) (44%, 33 of 75 fish), were found in English sole (Parophrys vetulus) exposed to creosote-contaminated sediments in Eagle Harbor, Puget Sound, WA. Sediments from the contaminated region of the harbor contained particularly high concentrations of aromatic hydrocarbons (e.g., benzo(a)pyrene and benz(a)anthracene), and a variety of nitrogen-containing aromatic compounds (e.g., carbazole and acridine). The composition of the aromatic compounds was characteristic of creosote. Dramatically lower concentrations of aromatic compounds were found in sediments from a reference site in which the bottom-dwelling fish examined were free of detectable neoplastic or preneoplastic hepatic lesions. Food organisms in the stomachs of the English sole from Eagle Harbor contained substantially higher concentrations of aromatic hydrocarbons than comparable organisms from the reference site. The concentrations of individual aromatic hydrocarbons in muscle and liver from the Eagle Harbor fish were low; however, high concentrations of metabolites of aromatic compounds were present in the bile. The findings strongly suggest an association between exposure to creosote and the prevalence of hepatic lesions, including neoplasms, in the bottom-dwelling fish, and furthermore support the putativemore » role of aromatic hydrocarbons in liver carcinogenesis in fish.« less

High prevalences of idiopathic liver lesions, including 7.5% hepatic neoplasms (e.g., hepatocellular and cholangiocellular carcinomas) and 16.7% foci of cellular alteration (putative preneoplastic hepatic lesions), were found in English sole (Parophrys vetulus) from waters near Mukilteo, a small community on Puget Sound in Washington State. Sediments from the sampling sites contained particularly high concentrations of aromatic hydrocarbons. Substantially lower concentrations of these compounds were found in sediments from another Puget Sound (reference) site in which fish showed no evidence of hepatic neoplasms or foci of cellular alteration. Stomach contents from the fish at Mukilteo contained substantially higher concentrations of the chemicals than did stomach contents of fish from the relatively uncontaminated site. High concentrations of metabolites of aromatic compounds were measured in the bile of fish from Mukilteo. These findings support previously observed relationships between sediment chemicals (e.g., aromatic hydrocarbons) and high prevalences of liver lesions in English sole from Puget Sound. In addition, a dietary route of uptake by English sole of environmental chemicals, including known carcinogens, was documented.

Metabolites of several two- and three-ring aromatci hydrocarbons (AHs) have been found in lives of English sole exposed to No. 2 fuel oil. Four metabolites of the C2H5-naphthalenes, six of the C3H7-naphthalenes and one each of fluorene, phenanthrene and anthracene have been partially characterized and their concentrations, which ranged from 50 to 1100 ng/g, were determined. Metabolites were separated from the liver matrix using an automated extractor/concentrator.The resulting extract was then purified by high-performance liquid chromatography, and the metabolites were characterized and quantitated by gas chromatography—mass spectrometry.

An automated extractor—concentrator was used to extract metabolites of naphthalene, 2,6-dimethylnaphthalene, and benzo[ a ]pyrene from serum, bile and liver homogenate of rainbow trout ( Samlo gairdneri ). The extracts were analyzed by reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection. Recoveries of naphthalene and 2,6-dimethylnaphthalene metabolites from all matrices were generally greater than 90%; however, the recoveries of benzo[ a ]pyrene metabolites from serum ranged from 37–99%. In addition, conjugated metabolites of polycyclic aromatic hydrocarbons (PAHs) were separated from non-conjugated metabolites and parent PAHs by using two diol columns with normal-phase HPLC. The extraction and separation techniques were also applied to isolated metabolites in samples from fish fed 2,6-dimethylnaphthalene.

High concentrations of chemicals have been found in sediments from urban areas of Puget Sound. Hundreds of organic chemicals (including certain aromatic hydrocarbons [AHs] and various chlorinated compounds) were identified. Statistical methods were used to evaluate possible relationships between the chemistry data and fish diseases. Positive correlations were found between the frequencies of liver neoplasms (e. g., hepatocellular carcinoma) and other liver lesions in English sole (Parophrys vetulus) and concentrations of AHs in sediment; such correlations were not found with chlorinated hydrocarbons. Strong evidence was also obtained to show that many organic chemicals in sediment are bioavailable to bottom-dwelling fish. Stomach contents (consisting mainly of benthic invertebrates) from English sole had concentrations of a number of AHs similar to those in the sediment from which the fish were taken. In these same fish, metabolites of many aromatic compounds were found in bile using a procedure combining HPLC with fluorescence detection. Further, the concentrations of certain xenobiotic metabolites in bile were correlated positively with the occurrence of liver neoplasms in English sole.

MOST echolocating porpoises and small whales (odontocete) possess a fatty protrusion on the forehead and a peculiarly formed lower jaw which flares into a posterior flange. Overlying this flange is a region of highly fatty tissue referred to by Norris1 as an acoustic window. The fatty tissues (>80% lipid) of the mandible and the melon are believed to be associated with sound transmission1–3. It is proposed4,5 that the melon functions as a sound lens, a concept consistent with the view that it is heterogeneous in terms of sound velocity and refraction6. Recent studies7–13 revealed that the lipids of acoustic tissues are different from those of the surrounding tissues. For example, the acoustic tissues contain triacylglycerols and wax esters rich in short and medium chain (C5–C12) acids, whereas blubber tissues are composed primarily of triacylglycerols containing long chain (C14–C22) acids. In the families Delphinidae7–9 and Monodontidae12, isovaleric acid (3-methyl butyric acid) and longer iso (gem-dimethyl) acids are present in large amounts in acoustic tissues. Furthermore, certain areas, such as the acoustic window and the inner melon, contain almost exclusively l,3-diisovaleroyl-2-acylglycerols and isovaleroyl wax esters (Fig. 1). These compounds are replaced by medium and long chain triacylglycerols in adjacent areas. Thus, specific lipid compositions with various proportions of branched structures are found in the putative areas of sound transmission14,15. The intriguing association between proposed acoustic pathways and unique lipid composition led us to study the acoustic properties of these lipids.

Radioactively labeled triacylglycerols, 1,3-dioleoyl-2-[1-14C]-palmitoylglycerol and 1,3-[9,10-3H]-dioleoyl-2-palmitoylglycerol, were incubated with dogfish (Squalus acanthias) serum for periods of up to 10.0 hr. Changes in the positional distributions of carbon-14 and tritium within the triacylglycerols in 5.0 hr and 10.0 hr indicate that intermolecular and intramolecular shifts occur among the fatty acids. In addition, a maximum of 8.3% of the carbon-14 and 5.9% of the tritium was incorporated into 1-alkyl-2,3-diacylglycerols; essentially all of this incorporated radioactivity was associated with the acyl chains in the 1.5 and 5.0 hr incubations. In the 10.0 hr incubations, however, 25% of the tritium incorporated into the 1-alkyl-2,3-diacylglycerols was associated with the 0-alkyl chains. Radioactivity was not incorporated significantly into free fatty acids in the 1.5 and 5.0 hr incubations. These results indicate that acyl transfer reactions take place among molecular species of triacylglycerols, as well as between triacylglycerols and 1-alkyl-2,3-diacylglycerols. In the latter case, the conversions appear to be operative in the virtual absence of net biosynthesis.

The metabolism of tritiated 2,6-dimethylnaphthalene (2,6-DMN) was studied in sea urchins (Strongylocentrotus droebachiensis) feeding on marine algae (Fucus distichus). The Fucus accumulated this hydrocarbon from sea water without converting it to metabolites. Most of the tritium accumulated by the sea urchins (e.g., 70.8% after 3 days) from feeding on 2,6-DMN-exposed Fucus was present in the exoskeleton (shell and spines). Moreover, after 3 days feeding, about 90% of the tritium in the total metabolite fraction of the gonads and digestive tract of the sea urchin was present as sulfate derivatives. These metabolites were identified through hydrolysis with aryl sulfatase, followed by thin-layer chromatography of the products. After 14 days of feeding, the tritium associated with the sulfate derivatives decreased in the gonads and digestive tract to 61 and 65%, respectively, of the total metabolite fraction. Hydroxy compounds from sulfatase hydrolysis were chromatographed using multiple elutions with toluene. The hydroxy isomers were separated and the Rf values were compared to those of pure reference compounds. The data indicated that 80% of the 2,6-dimethylnaphthyl sulfate contained the sulfate on the 1 and/or 3 position of the aromatic ring. Moreover, 6-methyl-2-naphthalenemethanol was not detected, which implies that sea urchins, unlike fish, metabolize alkyl-substituted aromatic hydrocarbons primarily through aromatic ring oxidations.

1. An h.p.l.c.-fluorescence technique was used to estimate relative concentrations of metabolites of xenobiotics in bile of 103 English sole (Parophrys vetulus) from both polluted and minimally polluted (reference) sites in Puget Sound, WA.2. Fish from polluted sites had concentrations of xenobiotics in bile with naphthalene-, phenanthrene- and benzo[a]pyrene-like fluorescence that averaged 9, 14 and 19 times, respectively, those of fish from reference sites.3. Within a polluted site, fish with liver lesions had significantly higher bile concentrations of xenobiotics with benzo[a]pyrene-like fluorescence than did fish without liver lesions.4. Individual metabolites of fluorene, phenanthrene, anthracene, biphenyl and dimethylnaphthalene were determined by g.I.e.-mass spectrometry in extracts of hydro-Is sed bile of three English sole from polluted waterways; concentrations ranged from 90 to 19000 ng/g, wet wt. Other xenobiotics were tentatively identified, but not quantified.

THE epidermal mucus of fish regulates swimming speed by controlling the hydrodynamic resistance of the skin surface1,2. The mucus is also presumed to serve as a defence against pathogenic organisms and is intimately associated with osmoregulation3,4. Because water-borne lead and mercury accumulate in the epidermal mucus of fish5,6, it is important to ascertain whether this phenomenon produces deleterious alterations in the mucus. No detailed information is, however, available to evaluate whether such alterations occur on exposure of fish to lead and mercury or whether a capability exists to depurate these metals.

1. Coho salmon exposed to water-borne lead and cadmium accumulated relatively high concentrations of each metal in gills, liver and kidney (primarily the posterior segment). 2. Cadmium concentrations in kidney increased for at least a month after termination of exposure; however, concentrations of lead remained about the same. 3. Highest concentrations of cadmium in kidney and liver were in cytosolic fractions, where substantial proportions were bound to proteins of 8900 molecular weight. Gills sequestered cadmium in the form of this readily-inducible metal-binding protein. 4. No specific lead-binding protein was identified in cytosolic fractions. This metal was primarily associated with proteins exceeding 55000 mol.wt.

Rainbow trout (Salmo gairdneri) were exposed to orally administered (/sup 3/H)naphthalene. Another group received naphthyl glucuronic acid and naphthyl sulfate via iv injection. Brain, liver, and blood were assayed for the parent compound and/or total metabolites. Individual naphthalene derivatives were determined by high-performance liquid chromatography (hplc) using either radiometric or on-line fluorimetric detection systems. Naphthalene concentrations in brain (8.2 pmol/mg dry wt at 16 hr after feeding) approximated those found at the same time in liver (7.4 pmol/mg dry wt). A nonconjugated naphthalene derivative, 1,2-dihydro-1,2-dihydroxynaphthalene, also accumulated in brain (0.041 pmol/mg dry wt after 16 hr), although to a lesser degree than in liver (0.10 pmol/mg dry wt after 16 hr). Conjugated naphthalene derivatives, 1-naphthyl sulfate and 1-naphthyl glucuronic acid, although present in liver and blood, were largely excluded from the brain. Low naphthalene hydroxylase activity (

Aquatic organisms convert aromatic hydrocarbons into a variety of conjugated and nonconjugated derivatives. Analytical techniques based on thin-layer chromatography (TLC) and high-pressure liquid chromatography (HPLC) were employed to separate, identify and quantitate individual metabolites from fish exposed to radiolabeled naphthalene and 2,6-dimethylnaphthalene. Significant differences in profiles of individual metabolites were found in relation to the type of biological sample analyzed. Liver of naphthalene-exposed salmonids contained eight polar derivatives, as shown by HPLC. Two nonconjugates (1-naphthol and 1,2-dihydro-1,2-dihydroxynaphthalene) and three conjugates (1-naphthyl glucuronic acid, 1-naphthyl sulfate and 1-naphthyl glucoside) were identified. HPLC revealed that brain of 3H-naphthalene-exposed trout contained essentially the nonconjugated derivatives, 1-naphthol and 1,2-dihydro-1,2-dihydroxynaphthalene. TLC showed that the metabolites from trout urine were 1-naphthol, 1,2-dihydro-1,2-dihydroxynapthalene, and 1-naphthyl glucuronic acid (99% of the total metabolites detected). Major components of the metabolite fractions of tissues and biological fluids were 1,2-dihydro-1,2-dihydroxy and glucuronic acid derivatives. Dihydrodiol derivatives arise from the corresponding arene oxides, some of which have been shown to be cytotoxic to certain mammalian systems.

Bottomfish and sediments were collected from 18 sites including a number of reference sites on the U.S. West Coast during the first year of the multiyear National Benthic Surveillance Project. Sediments and fish were analyzed for toxic chemicals, and fish were examined for diseases. Wide variations in the concentrations of aromatic hydrocarbons (AH), polychlorinated biphenyls (PCB), DDT and related compounds, and selected metals in sediments were found within locations ( i .e., embayments in the vicinity of major cities) and between locations. Concentrations of chemicals in tissues were generally less variable than those in sediments, apparently reflecting the ability of fish to integrate chemical sources over large geographical areas. Prevalences of diseases (i.e., fin erosion and liver lesions) were usually highest in fish exposed to the highest levels of environmental contaminants.

SummaryStructural isomers of monoenoic fatty acids in dogfish (Squalus acanthias) liver oil were determined. These fatty acids comprised 58% of total fatty acids and 87% of unsaturated fatty acids of the oil. Although it is known that polyunsaturated C20 and C22 fatty acids are present in quantity in most fish oils, dogfish-liver oil was found to contain substantial amounts of C20 and C22 monoenoic fatty acids as well. The following isomers were found in the oil: cis-9-hexadecenoic acid (6.1%), cis-9-octadecenoic acid (24.7%), cis-11-octadecenoic acid (9.8%), cis-9-eicosenoic acid (4.0%), cis-11-eicosenoic acid (5.1%), cis-11-docosenoic acid (6.7%), and cis-13-docosenoic acid (1.8%). It is suggested that most of the monoenoic fatty acids of dogfish-liver oil may be formed by addition of acetate units to oleic acid and other fatty acids having a Δ9 double bond.

The ratios of concentrations of diacyl glyceryl ethers to triglycerides are increased significantly in the livers of weighted dogfish (Squalus acanthias) in comparison to an unweighted control group. The hydrostatic properties of the liver may be regulated through the metabolism of these two classes of lipids which have different specific gravities.