1992 Fiscal Year Final Research Report Summary
Chronopharmacological study on the diurnal rhythms in bone metabolism.
| Project/Area Number |
02454422
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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 |
Functional basic dentistry
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| Research Institution | Tohoku university |
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Principal Investigator |
SHINODA Hisashi Dept. of pharmacology, Tohoku univ. Sch. of dentistry, Professor, 歯学部, 教授 (80014025)
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| Co-Investigator(Kenkyū-buntansha) |
HIRAFUJI Masahiko Dept. of pharmacology, Tohoku univ. Sch. of dentistry, Instructor, 歯学部, 助手 (20142987)
ONODERA Kenji Dept. of pharmacology, Tohoku univ. Sch. of dentistry, Lecturer, 歯学部, 講師 (40133988)
ENDO Yasuo Dept. of pharmacology, Tohoku univ. Sch. of dentistry, Lecturer, 歯学部, 講師 (50005039)
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| Project Period (FY) |
1990 – 1992
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| Keywords | circadian rhythm / bone resorption / mineralization / bisphosphonates / elcatonin / chronopharmacology / rat |
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| Research Abstract |
1) Time structure of diurnal rhythms in calcium transfer in and out of bone was determined in rats. Peak deposition of calcium into bone and growing incisor occurred at 2400h, with a nadir at 1200h, while, calcium release from bone was maximal around 1200-1600h and lowest late in the dard period. It was shown that a heat sensitive humoral factor(s) regulates diurnal rhythms in bone resorption in rats and in humans. 2) The effect of the time of drug administration was studied in rats using blockers of bone resorption. It was shown that there is a diurnal rhythm in the susceptibility of rats to elcatonin, sodium salicylate and bisphosphonates, which are known to have hypo calcemic or anti-osteolytic action. It was also shown that the magnitude of hypocalcemic or anti-osteolytic effects of these drugs depend on the phase of diurnal rhythms in bone resorption. The above results suggest that more predictable and efficacious results might be attained if the diurnal rhythmicities in bone metabolism were taken into consideration in designing treatment regimens with blockers of bone resorption.
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