| Co-Investigator(Kenkyū-buntansha) |
CHIBA Momoko Juntendo Univ. School of Medicine, Dept. Epidemiology and Environmental Health, Associate Professor, 医学部, 助教授 (80095819)
HOSHI Akio Nippon Dantal Univ., Dept. Health and Physical Education, Assistant Professor, 歯学部, 講師 (20139265)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2001: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2000: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Research Abstract |
Rare earth elements (REE) are widely used in of high technology field, however, the information on their biological effects is not readily available. The effects of REE on reproductive functions and bone metabolism were investigated in this project Terbium (Tb) and Ytterbium (Yb) intravenously administered in male mice (5 weeks old) were distributed mainly in liver, and were also in spleen, kidney, lung, pancreas, heart, thymus, submaxillary gland, brain, bone, muscle, genital organs such as testes, epididymis, and seminal vesicle. The concentrations of Tb and Yb in organs were roughly proportioned to dose, however, those in testis indicated reverse relation in certain range of dose. Distribution ratio vs. dose in testis showed tendency to increase with decrease of dosage. The concentrations of Yb in testis were higher than Tb but slight pathological changes were observed only for Tb. Distribution ratio of Tb or Yb in bone vs. dose was from several to ten % and tended to increase with decrease of dose. Bone mineral density decreased slightly by administration of Tb. REE was detected in bone of control mice without special intake of REE. The concentrations were from several to 20 ng/g dry bone. Source of REE was thought to be mouse diet that contained several to 80 ng/g of rare earths. The pattern of REE in bone did not agree with those in mouse diet suggesting that the behavior of REE in the body are different depending on each element
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