Present status of cytotoxicity studies with fish cell culture and quantitative structure-activity relationships (QSAR) in aquatic toxicology were discussed from the viewpoint of utilization of alternative species or methods for toxicity tests. In vitro cytotoxicity studies with fish cell culture were much less than those with mammalian cells. However, recently cytotoxicity studies comparing toxicological responses in fish cell with those in whole fish and mammalian cells are increasing. Reproduction, unscheduled DNA synthesis (UDS) and cromosomal aberration of cells are used as a measure of effects on cells. Especially, UDS and cromosomal aberration are used in studies to detect carcinogenic substances in an aquatic environment. In QSAR studies, steric parameters e. g. molecular connectivity index were taken into consideration as a physical-chemical properties in addition to well-known n-octanol/water partition coefficient recently and it is concluded that its ability to predict the toxicity is successful for range-finding and test priority determination among the chemicals.

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In order to clarify the relationships between the test methods for ecotoxicity, the tests by the various organisms were carried out. We used 6 animals (activated sludge, Daphnia, carinata, Oryzias latipes, Eisenia foetida, Tetrahymena pyriformis and Dugesia japonica) and 3 water plants (Porphyra yezoensis, Lemnaceae and Chlorella vulgaris). The high correlations were observed between the test results of the various determining manners by the use of the same animals (D. carinata, O. latipes or D. japonica). The reproduction test of 14 d by D. carinata gave the most sensitive results in average among the 9 tests examined. The tests by activated sludge, E. foetida and water plants were not sensitive. The tests by O. latipes, D. japonica and T. pyriformis showed moderate sensitivity. The correlations between the water plants and the animals were generally low, and this showed a peculiality of water plants in assessing ecotoxicity.

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Cytotoxicity and effects on ultraviolet (UV) killing to Chinese hamster ovary (CHO) cells of arsenic compounds were examined by means of clonogenic survival assay, and the effects on DNA repair in CHO cells of arsenic compounds were examined by unscheduled DNA synthesis (UDS). Inorganic arsenic compounds were more lethal to CHO cells than organic arsenic compounds. Furthermore, arsenite was much more cytotoxic to CHO cells than arsenate. Treatment with inorganic arsenic compounds after UV irradiation enhanced UV killing to CHO cells. These effects were observed even when the cells were treated with arsenic for 1 h after UV irradiation. However, when the cells were treated with arsenic at 18 h after UV irradiation, arsenic had little effect on the UV killing to CHO cells. On the other hand, treatment with organic arsenic compounds caused no obvious potentiation of UV killing to CHO cells. The UV-induced UDS decreased by treatment with arsenite for 4 h after UV irradiation, it decreased a little with arsenate. However, when the cells were treated with arsenate for 2 h before UV irradiation, arsenate caused reduction of the UV-induced UDS. These results suggest that inorganic arsenic compounds inhibit DNA repair.

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Thiabendazole (TBZ) suspended in olive oil or 3% gum arabic was given orally to pregnant ICR mice on day 15 (a single administration group) or during days 6 to 15 (repetitive administration group) of gestation at dose levels of 700, 350 and 100 mg/kg/d and TBZ in the liver, placenta and fetus of mice was analyzed by means of gas chromatography with FPD at 12 and 24 h after final administration. TBZ was transferred to the fetus from the placenta in maternal mice treated with TBZ and the concentration of TBZ in the organs increased with an increase in dose level. TBZ and its metabolite, 5-hydroxythiabendazole (5-OH TBZ, including glucuronide and sulfate of it), in the blood, liver, kidney, placenta and fetus of mice treated with 700 mg/kg/d of TBZ were analyzed by means of fluorometry at 1, 2, 6, 12, 24, 48 and 120 h after final dose. The time course of concentration of TBZ and 5-OH TBZ in the liver, kidney, placenta and fetus showed a similar pattern to that in the blood. The maximum concentration of TBZ in repetitive administration group was observed at 1 h after final dose and was no difference between those in two vehicles, whereas in a single administration group the maximum concentration in TBZ-olive oil group at 1 h was higher than that in TBZ-gum arabic group at 1 or 2 h. The concentration of 5-OH TBZ in repetitive administration group was higer than that in a single administration group within 12 h after final dose in both different vehicles.

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Monitoring system for environmental pollutants (ECD-sensitive substances in blue mussels) was developed by means of capillary gas chromatography. System-flow and the algorism of the software were summarized as follows. Peak heights and retention times of ECD sensitive substances in blue mussels were integrated and were transferred from GC to personal computer by the on-line system. Retention times were transferred to retention indices and detected components were quantified by using DDE as a standard. Common components were selected from detected substances, and data-files were prepared for statistical analyses. Pattern analyses of these components in blue mussels were carried out by means of the calculation of similarity factors and cluster analysis. From these analyses the differences and the changes of the quality and the quantity of pollutants in blue mussels are clarified. Continuous monitoring and accumulation of data are planned for the standarization of the pollution patterns of various seas. Long-term tendency of the environmental pollution would be recognized by the comparative analyses of standarized patterns and a later monitoring result.

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Monitoring system for environmental ECD sensitive substances by means of capillary ECD gas chromatography (ECD-GC) was developed and applied to blue mussels as a model biological indicator. Thirty-three blue mussel taken from Osaka North Port, Osaka Misaki-cho and Hokkaido Funkawan Bay were analyzed. In addition, samples from Funkawan Bay were acclimated in the three different seawaters of Osaka North Port, Chiba and Yokohama and analyzed. Peak heights and retention times of capillary ECD-GC sensitive substances were recorded on the disk of personal computer. After retention times were transferred to retention indices for organochlorine compounds, detected components were quantified by using DDE as a standard. Common components were selected from the detected substances in order to prepare new data-file for pattern analyses. Calculation of similarity factors and cluster analysis were carried out on the patterns and the total concentrations of the common components. From these analyses, the differences and the changes of both quality and quantity of pollutants were clearly observed. The results showed that the developed system would be applicable to a repid monitoring method for environmental pollutants.

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By using gonyautoxin-1, 2, 3 (GTX_{1, 2, 3}), which are members of paralytic shellfish poison (PSP), isolated from PSP-infested scallops Patinopecten yessoensis in Funka Bay, Hokkaido, a basic research was made to reveal bioconversion mechanism of PSP components accumulated in bivalves by ingestion of toxic plankton Protogonyaulax tamarensis. The scallops were extracted with acidified ethanol (pH 2.0). The extract was defatted with chloroform, treated with activated charcoal, applied successively to three types of column chromatography on Bio-Gel P-2, Amberlite CG-50 II and Bio-Rex 70. The toxins were finally purified by cellulose acetate membrane electrophoresis. A mixture of GTX_{1, 2, 3} thus obtained was treated by the methods as described below. A mixture of GTX_{1, 2, 3} was treated at 37°C for 24 h or 48 h with glutathione (GSH), L-cysteine (L-CySH), flavin adenine dinucleotide (FAD), β-diphosphopyridine nucleotide (β-NAD) and β-diphosphopyridine nucleotide disodium salt (reduced form, β-NAD·2Na) solutions (pH 5.8), respectively. The composition of reaction products obtained was examined by fluorodensitometry. The results were as follows. A mixture of GTX_{1, 2, 3} (GTX₁ : 2%, GTX₂ : 71%, GTX₃ : 27%) was treated with GSH, to give a mixture of GTX₁ (21%), GTX₃ (trace) and STX (79%) after 24 h, and to give a mixture of GTX₁ (trace), GTX₃ (trace) and STX (100%). A mixture of GTX_{1, 2, 3} as above was treated with L-CySH, to give a mixture of GTX₁ (30%), GTX₃ (trace) and STX (70%) after 24 h, and to give a mixture of GTX₁ (30%), GTX₃ (trace) and STX (70%) after 48h. However, GTX_{1, 2, 3} was not converted to other PSP components by treatment of FAD, β-NAD and β-NAD·2Na. The results obtained here were thought to indicate the possible bioconversion of GTX_{1, 2, 3} to STX by mild reducing agents such as GSH and L-CySH in vivo.

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A spectrophotometric method for the determination of citric acid (Cit) was established by ternary complex formation among Cit, o-hydroxyhydroquinonephthalein and iron (III), and the method was applied to the assay of Cit in foods. Beer's law held up to ca. 7μg of Cit (as citrate ion) in the final volume of 10ml, the apparent molar absorptivity at 610nm and the relative standard deviation being 3.2×10⁵ 1·mol^-1·cm^-1 and 0.91% (n=8) for 3.8 μg of Cit. Though tartaric acid, malic acid, ascorbic acid, phosphoric acid and quinic acid in small amounts affected the determination of Cit, the effects of these substances could be minimized by the standard addition method. The coexistence of monocarboxylic acids, such as acetic acid and lactic acid, and polycarboxylic acids having no hydroxy groups, such as maleic acid, succinic acid and oxalic acid, scarcely interfered with the assay, even in 20-to 100-fold molar excess over Cit. Recovery of Cit from various samples were satisfactory (95-103%). Compared with the values obtained by the pentabromoacetone method and the enzymatic method, the values determined by this method were somewhat larger, but the present method is simple and highly sensitive, and may be useful and convenient for the determination of Cit in foods.

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We investigated the generation of mutagenicity by heating in fish meats with various water contents and in model system solutions containing creatinine, glucose and glycine. Comparison of the formation of mutagenicity in fish meats heated under air and steam suggested that loss of water accelerated the generation of mutagenicity. Experiments with the model system solutions indicated that the mutagenic activity produced in water alone was much less than that produced in the 10% water-diethylene glycol (or dioxane) system. Thus, a large amount of water inhibited the formation of the mutagenicity, and loss of water stimulated it. It seems unlikely that the activity of water influenced the formation of mutagenicity.

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Daily dietary intakes of 6 polycyclic aromatic hydrocarbons (PAHs) [i. e. anthracene (An), pyrene (Py), benzo [b] fluoranthene (B [b] F), benzo [k] fluoranthene (B [k] F), benzo [a] pyrene (B [a] P), benzo [g. h. i] perylene (B [g, h, i] P) were investigated through duplicate portion study. Samples were collected from daily diets of 6 women (from 25 to 56 years old) for one week in July, 1985. The daily intake of Py, which was most abundant in these PHAs, was found to be 0.15-7.3 μg/d in range and 0.98 μg/d in avarage. And those of B [a] P and B [b] F, which are typical carcinogens, were 0.02-1.6 μg/d (avarage : 0.084 μg/d) and nd-1.3 μg/d (avarage : 0.234 μg/d), respectively. Total daily intakes of PAHs were calculated to be 0.36-13.67 μg/d (avarage : 1.663 μg/d). And it was found that there was about 38 times difference among daily dietary intakes of PAHs.

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