1989 Fiscal Year Final Research Report Summary
Immunoelectron microscopic studies on the intracellular processing and transport of pro-opiomelanocortin (POMC)
| Project/Area Number |
63570004
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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 anatomy (including Histology/Embryology)
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| Research Institution | Institute of Endocrinology, Gunma University |
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Principal Investigator |
KUROSUMI Kazumasa Dept. Morph., Inst. Endocrinol., Prof. Gunma Univ., 内分泌研究所, 教授 (20008593)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Shigeyasu Dept. Morph., Inst. Endocrinol., Res. Assoc. Gunma Univ., 内分泌研究所, 助手 (90146233)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Pituitary gland / Pro-opiomelanocortin cell / Immunocytochemistry / Intracellular processing / Ultracryomicrotomy / Immunogold method / Synthetic peptide |
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| Research Abstract |
A synthetic peptide (ST-1) corresponding to the cleavage site between ACTH and beta-lipotropic hormone moieties of murine pro-opiomelanocortin (POMC) was constructed and its polyclonal antibody was generated. This antiserum immunoprecipitated only POMC from extracts of AtT-20 cells. Moreover, an antiserum raised against porcine ACTH immunprecipitated both ACTH(1-39) and POMC. When ultrathin frozen sections of melanotrophs in the rat pars intermedia were immunolabeled with anti-ST-1 followed by protein A-gold, gold particles indicating the presence of POMC were selectively found in the immature secretory granules in the Golgi area. In addition, the immunolabeling was also observed in the cisternae of the Golgi apparatus. In contrast, with polyclonal antibody specific for alpha-melanocyte- stimulating hormone, the gold particles were found exclusively in the mature secretory granules, with none seen in the immature secretory granules. With anti-ACTH serum, gold particles were observed in the immature and mature secretory granules. In cortcicotrophs in the pars distalis, many gold particles indicating the presence of POMC were observed in immature and mature secretory granules, similar to the result with anti-ACTH, thus suggesting that the processing might occur in the relatively mature granules. These results suggest that the intracellular sites of the processing of POMC are different between melanotrophs and corticotrophs in the pituitary.
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Research Products
(12 results)
