1988 Fiscal Year Final Research Report Summary
Experimental studies on toxicity of and requirement for the trace elements: its modification by the environmental factors.
| Project/Area Number |
61480162
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Hygiene
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| Research Institution | University of Tokyo |
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Principal Investigator |
SUZUKI Tsuguyoshi Professor,Dept.Human Ecology,Sch.Health Sciences,Fac of Medicine,U of Tokyo, 医学部, 教授 (80009894)
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| Co-Investigator(Kenkyū-buntansha) |
HONGO Tetsurou Instructor,Dept.Human Ecology,Sch Health Sciences,Fac Medicine,U of Tokyo, 医学部, 助手 (90199563)
KASHIWAZAKI Hiroshi Lecturer,Dept.Human Ecology,Sch.Health Sciences,Fac Medicine,U of Tokyo, 医学部, 講師 (60004735)
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| Project Period (FY) |
1986 – 1988
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| Keywords | Toxicity of trace elements / Requirement of trace elements / Environmental factors / Selenium / Mice / Modification of toxicity by environmental factors |
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| Research Abstract |
The purpose of this study is to provide basic and experimental information about modification of toxicity and/or fequirement of trace metals in human populations by their various living environments. Specifically, we examined the influence of ambient temperature (Ta) on toxicity of a trace element, selenium, using mice as the experimental animal.
Major findings in this study are as following;
1. We found hypothermia as a transient and Ta-dependent effects of sublethal dose of sodium selenite (SS). The acute lethality of SS was raised at higher Ta, where hypothermia did not occur.
2. The Ta in the short period of post-injection seemed to have a critical role in determining the delayed toxic effects of a single SS administration. This modification of toxicity by Ta was not cancelled by a prior acclimatization of mice to Ta. Thus Ta is significant in evaluating the toxicity of SS.
3. Another acute effect of SS, hyperphagia, was also Ta-dependent. On the other hand, other two biological effects of SS, i.e.; induction of metallothionein, and attenuation of Hg toxicity, did not appear to relate with Ta and/or the hypothermic event.
4. Mechanism of SS hypothermia was not elucidated. Since other chemical forms of selenium compounds also induced hypothermia, Se might be the responsible agent; however, reselenomethionine did not cause hypothermia. Since our preliminary study showed that several of other inorganic salts induced hypothermia, we are now investigating the specificity of this effect.
5. Our future project may include 1) modification of requirement for Se and Zn by Ta; and 2) the effects of hypoxia on the toxicity and/or requirement for Se.
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