1988 Fiscal Year Final Research Report Summary
Studies on metabolisms of radioactive materials and radiosensitivity under zinc deficiency
| Project/Area Number |
61560333
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
基礎獣医学
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| Research Institution | Iwate University |
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Principal Investigator |
MATSUSAKA Naonori Faculty of Agriculture, Iwate University Professor, 農学部, 教授 (70003754)
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| Co-Investigator(Kenkyū-buntansha) |
SHINAGAWA Kunihiro Faculty of Agriculture, Iwate University Associate Professor, 農学部, 助教授 (60133906)
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| Project Period (FY) |
1986 – 1988
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| Keywords | zinc / metabolism / Zn-deficiency / whole-body retention / placental transfer |
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| Research Abstract |
Whole-body retentions of radioactive Zn were measured by gamma counting periodically after a single oral administration of the isotope to young and adult mice maintained on a Zn-deficient and Zn-normal diet. The young mice had higher retentions than the adult in both the Zn-deficient and Zn-normal groups Under Zn deficiency, however, greater amount of radioactive Zn was absorbed from the gastrointestinal tract in both age groups. Higher levels of stable Zn in the diet was effective for reducing the body retentions of radioactive Zn.
In addition, placental transfer of radioactive Zn was studied inpregnant mice of late gestational stage, supplied a Zn-deficient and Zn-normal diet. After a single oral administration of the isotope to pregnant mice, whole-body retentions were measured until parturition. The wholebody retention values of the Zn-deficient groups remained at higher levels until parturition. An abrupt decrease of the retention values was observed in both Zn-deficient and Zn-normal dams just after parturition: the differences between the values one day before parturition and the values just after pargurition account for the amount of the radioactive Zn incorporated into a litter of offsprings through placenta in utero.
Radiosensitivity under Zn deficiency was observed in SPF mice after irradiation of gamma rays (750 rad). Contrary to our expectation, mice of a Zn-deficient group showed lower radiosensitivity than those of a Zn-normal group. The mechanism of this phenomenon is under investigation.
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