Iguchi, T. [Yokohama City Univ., Yokohama (Japan)
The environmental endocrine disruptor, or the so-called environmental hormone, is outlined. Hormones are secreted from endocrine glands in trace amounts, transported by blood, and exert influence on the target organs and distal cells, this to sustain constancy in living organisms. There are two types: peptide hormones which are rows of amino acids and steroid hormones which are composed of cholesterol. Endocrine disruptors are chemical substances discharged into the environment which, once taken into human organisms, disrupt endocrine systems, some acting like female sex hormones and others resisting male sex hormones. Many a wild animal are found affected by them. They are accumulating in human organisms too. Synthesized chemical substances such as DDT, PCB, dioxins, and alkylphenols present in the water system affect a fish by disrupting its endocrine, immunity, nerve, growth, and regeneration. Embryos and larvae are quite susceptible, easy to turn abnormal. Voices are high across the world for the study of environmental endocrine disruptors. Introduced in this report are some animal experiments, typical cases of impact on the ecosystem, and systems for detecting environmental endocrine disruptors. 36 refs., 1 tab.
Canada continued use prohibition of gene recombination cattle somatotropin (BST) which stimulated milk increased production of this company in spite of request of Monsanto Co.. The cow that BST was administered is based on the report of veterinary surgeon that causes reproductive function and lowering in the life, dysbasia and increase in the mastitis on this. From the research report that BST causes thyroid gland cyst of the male rat in U.S.A., consumer organization and environment group petition FDA for the elimination of BST from the U.S.A. market. In the meantime, Monsanto Co. in the report which Canada adopted, chemical structure is different, and it reports that it uses BST of other company in which dosing method and dosing frequency differ and disregards the report of Cornell university in which the life of the cow administered more and more does not lower BST. (translated by NEDO)
Report on evaluation on endocrine disturbing effect of chemicals and development of test methods; 1999 nendo kagaku busshitsu no naibunpi kakuran koka ni kansuru hyoka oyobi shikenho no kaihatsu hokokusho
With regard to endocrine disturbing effect being the new deleteriousness of chemicals, data were collected and evaluated by using the existing testing methods, data were collected by using the screening test, the testing methods were developed, and international investigation was carried out to establish the risk evaluation methods. In the evaluation by using the existing test methods, seven substance groups deficient in deleteriousness data qualitatively and quantitatively were given reproduction toxicity tests to evaluate availability of the endocrine activity. Development of the screening test method has been carried out by participating the validation test by OECD to make the uterotrophic assay method and the Hershberger assay method a test guideline having international matching property. International investigations to establish the risk evaluation were executed on the molecular mechanism of nuclear receptors, the chemical, metabolic and environmental behaviors of endocrine active substances, the effects of the endocrine active substances on experimental animals and human, the utilization thereof for risk assessment in human, and the effects of endocrine disturbance acting substances in wildlife species. (NEDO)
What correlation does the electron structure of environmental hormones have with manifestation of their toxicity and biological activity. Application of the hardness conception to biology; Kankyo horumon no denshi kozo wa sono dokusei ya seibutsu kassei no hatsugen ni donoyona sokansei wo motsunode aroka. Hardness gainen no seibutsugaku eno oyo
Kobayashi, S.; Tanaka, A. [Showa College of Pharmaceutical Sciences, Tokyo (Japan); Sameshima, K. [Fujitsu Ltd., Tokyo (Japan)
This paper indicates that the relationship between toxicity and biological activity of environmental hormones such as dioxin and their chemical structures may be predicted by using parameters (physical quantity) derived from the chemical hardness conception. According to this conception, softness and hardness of molecules are important in addition to electron receptivity and donation properties of molecules. Soft compounds facilitate electrons to migrate. Chlorine displacement of dioxin skeleton to 2nd, 3rd, 7th and 8th orders softens the molecules and displacement to 1st, 4th, 6th and 9th orders hardens them. The toxicity and biological activity of the environmental hormones cannot be explained only with the fit model of key-keyhole with the counterpart they act on (receptor). The softer the chemical hardness, the greater the toxicity and biological activity. Development has been made on an absolute hardness versus absolute electrical negative activity diagram to learn electron structure of molecules. This diagram indicates that the toxicity of dioxin depends more strongly on the chemical hardness than the strength of the electrical negativity, and the softer the hardness, the stronger the toxicity. (NEDO)
FY 1998 results of the intellectual basement project using functions of private companies (venture promotion type basement creation R and D project). Development of endocrine disrupter testing method and development of environmental assessment method; 1998 nendo naibunpi kakuran busshitsu ni taisuru shiken hoho kaihatsu oyobi eikyo hyoka shuho kaihatsu hokokusho
For the purpose of assessing the risk in relation to endocrine disrupting chemicals, the following were conducted: development of testing/assessment method for endocrine disrupting chemicals, survey of the actual exposure assessment, development of measuring method for the concentration in the environment. In the development of the testing method, the following were carried out: development of a high-throughput screening method for evaluating endocrine disrupting chemicals; as screening testing method using mammals, uterotrophic assay, Hershberger assay using castrated male rats, thyroid hormone assay in pubertal rats, enhanced OECD 407 test guideline for 28-day toxicity test; study on yeast two-hybrid assay for endocrine disrupter; sex-reversal assay for suspected endocrine disrupting chemicals using S-rR strain medaka. In the development of exposure assessment method, estrogenic potency of individual nonylphenol congeners isolated from technical mixtures; determination of endocrine disrupters and related chemicals from industry and nature origin in river water and sediment; research for the flow of industrial origin chemicals; reconstruction of pollution history of chemicals using sediment cores. (NEDO)
Fiscal 1997 report on the results of the international standardization R and D. Measurement of ultra-micro chemical substances and measuring methods of hormone effects; 1997 nendo seika hokokusho kokusai hyojun soseigata kenkyu kaihatsu. Chobiryo kagaku busshitsu no keisoku horumon eikyo sayo sokuteiho
Concerning the measurement system of ultra-micro hazardous chemical substances in the global environment, the paper examined the present situation of chemical substances such as dioxins, made an experimental study on the method to analyze dioxins in exhaust gas from an aspect of international consistency, and worked out a JIS draft. As to the standard measuring method of hormone effects of chemical substances, the paper developed the competitive bonding experiment system to measure bonding ability of chemical substances to homo sapiens estrogen receptor (ER). By measuring ER bonding ability of 78 kinds of chemical substances, the measuring method was developed. In the development of the assay system for detection of hormone-like compounds, the assay system with transfer activity via estrogen receptor as an index was established using cultured cells and yeast. Further, the development was made of a measuring method of receptor bonding activity of hormone-like substances. 33 refs., 151 figs., 66 tabs.
Fiscal 2000 research and development of technologies for intelligent infrastructure creation and utilization. Development of high-precision screening assay system for endocrine disrupting chemicals and construction of database; 2000 nendo chiteki kiban sose riyo gijutsu kenkyu kaihatsu. Naibunpi kakuran busshitsu no koseido screening shiken hoho no kaihatsu oyobi data kiban seibi
Research and development is carried out for the establishment of a system for assaying endocrine disruption now presenting itself as a hazard and for the application of the assay system to important chemicals and chemicals under development for the detection of presence of endocrine disrupting action in them. In this fiscal year, for the establishment of a reporter-gene assay system, cell characteristics were clarified through the determination of the expression sequence of the produced cell, the determination of the stable conservation period of the cell, and the study of the sustenance of activity. Studies were conducted, targeted at the stable supply of cells usable for high-throughput screening. Basic data were collected for the Hershberger assay being developed by OECD (Organization for Economic Cooperation and Development) and for the repeated administration test method for assaying thyroid hormone action by use of pubertal rats. For the assay of impact on environmental organisms, moreover, basic data were collected for the establishment of testing methods using fishes and amphibians. (NEDO)