1986 Fiscal Year Final Research Report Summary
Age-dependent alteration in cell function of rat salivary glands
| Project/Area Number |
60480401
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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 | The University of Tokushima |
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Principal Investigator |
ISHIDA Hajime Professor, The Univ. of Tokushima, School of Dentistry, 歯学部, 教授 (70028364)
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| Co-Investigator(Kenkyū-buntansha) |
UNO Yoshiharu Research Assistant, The Univ. of Tokushima, School of Dentistry, 歯学部附属病院, 助手 (60183208)
KODA Naohiko Research Assistant, The Univ. of Tokushima, School of Dentistry, 歯学部, 助手 (60144995)
KONDO Michihiro Research Assistant, The Univ. of Tokushima, School of Dentistry, 歯学部, 助手 (20186860)
ISHIKAWA Yasuko Research Assistant, The Univ. of Tokushima, School of Dentistry, 歯学部, 助手 (40144985)
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| Project Period (FY) |
1985 – 1986
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| Keywords | Aging / Drug Receptors / Amylase Secretion / Ion Release / Phosphorylation / Non-histone Protein / Cell Proliferation / 細胞分裂 |
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| Research Abstract |
Age-dependent alterations of drug receptors and phosphorylation of nuclear proteins in rat salivary glands were studied in relation to the secretory response and the cell proliferation.
1. Binding studies with ( <^3H> )dihydroalprenolol and ( <^3H> )quinuclidinyl benzylate showed the age-dependent changes in the number of <alpha> -, <beta> -adrenoceptors and muscarinic receptors in rat parotid glands. However these changes were not coupled with those in responsiveness of the tissues to secretagogues during aging. The affinities of <beta> -agonists, not of <beta> -antagonists, to <beta> -adrenoceptors were significantly changed with increasing age. The age-dependent changes in the affinities were coupled with those in amylase secretory response of the tissues to <beta> -agonists.
2. <Alpha_1> -adrenergic stimulated potassium release by parotid cell declined during aging The decline could not be responsible for age-dependent changed in <alpha_1> -adrenergic responsiveness. Calcium efflux s
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timulated directly by inositol triphosphate from parotid cell was reduced by about 50% with increasing age. Differences are not due to a reduction in uptake of the phospholipid into older cells, but suggest and age related defect in the ability of inositol triphosphate to liberate calcium from intracellular store of parotid cells.
3. It was obvious from the results obtained by using a salivary gland nuclei isolated from isoproterenol-treated rats that the phosphorylation of the non-histone proteins had an important role in the events controlling the syntheses of RNA which preceeded the replication of DNA. The phosphorylation of non-histone proteins of rat salivary gland nuclei was significantly increased after birth. The levels of phosphorylation reached a maximum at 4-week old rats and declined to those of 16-week old rats. The leveles were also maintained in nuclei isolated from rats of 12 months after birth. However, any changes in the phosphorylation of histone proteins were not observed with increasing age. The age-dependent changes in the phosphorylation of non-histone proteins were coupled with those of protein kinase activities associated with chromatin. Less
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