1991 Fiscal Year Final Research Report Summary
STUDIES ON FUNCTION OF LYSOSOMAL ENZYMES IN MATURATION AMELOBLASTS IN RAT
| Project/Area Number |
02670828
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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 |
Functional basic dentistry
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| Research Institution | DEPARTMENT OF PHARMACOLOGY, NAGASAKI UNIVERSITY SCHOOL OF DENTISTRY |
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Principal Investigator |
MATAKI Shiro DEPT. PGARMACOL. NAGASAKI UNIV. SCHOOL OF DENTISTRY, ASSOCIATE PROFESSOR, 歯学部, 助教授 (80157221)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAI Eiko DEPT. PHARMACOL. NAGASAKI UNIV. SCHOOL OF DENTISTRY, EDUCATIONAL STAFF, 歯学部, 教務職員 (10176612)
SAKAI Hideaki DEPT. PHARMACOL. NAGASAKI UNIV. SCHOOL OF DENTISTRY,RESEARCH ASSISTANT, 歯学部, 助手 (40225769)
OZAKI Miho DEPT. PHARMACOL. NAGASAKI UNIV. SCHOOL OF DENTISTRY, RESEARCH ASSISTANT, 歯学部, 助手 (50191341)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Maturation ameloblasts / Lysosomal enzymes / Cathepsin B / Cathepsin D / Cathepsin E |
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| Research Abstract |
Amelogenesis is characterized by two major stages, i.e. secretory stage and maturation stages. Especially the maturation stage is rather important one in relation to forming highly mineralized enamel. During enamel development the secreted enamel matrix protein is resorbed by maturation stage ameloblasts while calcification process of enamel progresses. Current evidences suggest that several types of proteinases hydrolyze enamel matrix proteins extracellularly. However, it is also raised that several intracellular proteinases have important roles in maturation stage ameloblasts. This study is undertaken to clarify the function of lysosomal enzymes in maturation stage ameloblasts of rat incisor. Firstly, chloroquine was used as a lysosome inhibitor to examine the involvement of lysosomal function in maturation enamel. Although effect of chloroquine on GBHA staining of rat incisor is a little even after successive injection for 48 days, in the early maturation stage GBHA staining ability
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corresponding to smooth-ended ameloblasts is reduced. This result suggests that typical morpholoical change of ruffle-ended ameloblasts to smooth-ended ameloblasts is disturbed by chloroquine injection and lysosomal function is partially related to maturation stage of enamel. Second, localization and the enzyme activities of cathepsin B, D and E in maturation stage ameloblasts. The antiserum against cathepsin B, D and E were raised in rabbits and the IgG fraction from these antisera were prepared. Frozen section of maturation stage ameloblasts was immunostained by a peroxidase/antiperoxidase (PAP) procedure. Cathepsin B and cathepsin D were detected on granular materials in cytoplasm of ameloblasts and papillary layer cells.that seems to correspond to lysosome system. The immunoreaction of the two enzymes increased gradually in incisal direction. However, immunoreaction for cathepsin E was detected over papillary layer cells but not in maturation stage ameloblasts. These results suggests that difference in localization of these cathepsins in rat incisor enamel organ reflect difference in physiological function during enamel development. Less
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Research Products
(8 results)
