1995 Fiscal Year Final Research Report Summary
Inhibitory effect of opioids on GDP-GTP exchange reaction
| Project/Area Number |
06670109
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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 |
General pharmacology
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| Research Institution | Osaka University |
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Principal Investigator |
SAITO Kihachi Osaka University, Faculty of Dentistry, Professer, 歯学部, 教授 (40110788)
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| Co-Investigator(Kenkyū-buntansha) |
UCHIDA Yoshiyasu Osaka University, Faculty of Dentistry, Research Assistant, 歯学部, 助手
MAEDA Sadaaki Osaka University, Faculty of Dentistry, Assistant Professor, 歯学部, 講師 (00135732)
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| Project Period (FY) |
1994 – 1995
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| Keywords | MORPHIEN / AMYLASE SECRETION / G PROTEIN / GTPase |
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| Research Abstract |
Rat parotid acinar cells were isolated and made permeable for small molecules by alpha-toxin for determining species of GTP binding proteins involved in secretory processes and for studying effect of morphine on it. It was found that aluminum fluoride (AlCl_3/NaF) enhanced the secretion of amylase. Enhanced secretion of amylase was also observed by dibuturyl-cyclic AMP but not by cyclic AMP.However, cyclic AMP was effective in enhancing the secretion following permeabilization of cells by alpha-toxin. Following the treatment of cells with alpha-toxin, both GTP and GTP-gamma-S were able to enhance the secretion. Morphine reduced AlCl_3/NaF-or GTP-induced secretion of amylase, while it was without effect on GTP-gamma-S-induced secretion, . Photoaffinity labeling by the use of (^<32>P) 4-azidoanilido GTP revealed the incorporation into 43 kDa and 31 kDa protein. Incorpotration was further enhanced with AlCl_3/NaF.Morphine reduced the labeling of 43 kDa protein. When (gamma^<32>P) GTP was preloaded into permeabilized acinar cells and its hydrolysis was measured, morphine stimulated and AlCl_3/NaF inhibited GTPase activity. These results suggested the involvement of 43 kDa GTP binding protein in the secretion of amylase. Furthermore, morphine reduced the secretion of amylase by stimulating GTPase activity and by reducing the incorporation of GTP into 43 kDa protein.
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Research Products
(4 results)
