Document Detail


Vitamin B6 metabolism in McA-RH7777 cells.
MedLine Citation:
PMID:  3342390     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The metabolism of vitamin B6 in McA-RH7777 cells has been characterized with respect to pyridoxal 5'-phosphate (PLP) levels, and the activities of pyridoxine (PN) kinase (EC 2.1.7.35) and pyridoxine 5'-phosphate (PNP) oxidase (EC 1.4.3.5). PLP levels (12.4 +/- 4.4 ng/mg protein) were at the lower end of the range found for Morris hepatomas, carcinogen-induced rat hepatomas, and liver from rats fed a PN-deficient diet. PN kinase activity was about one-third of that found in normal rat liver. PNP oxidase appeared to be absent in high-speed supernatants of homogenates prepared from McA-RH7777 cells. The absence of PNP oxidase was supported by enzymatic and immunological data. These findings resemble those found previously for Morris hepatoma 7777. In contrast to rat liver, such preparations caused little or no release of volatile counts upon incubation with either [3H-C4']PN or [3H-C4']PNP. High-speed supernatants of homogenates prepared from both McA-RH7777 cells and Morris hepatoma 7777 were very much less capable than similar preparations from rat liver in converting [G-3H]PN to PLP and pyridoxamine 5'-phosphate. Despite the apparent absence of PNP oxidase, intact confluent or log-phase McA-RH7777 cells were capable of converting [G-3H]PN to PLP and pyridoxamine 5'-phosphate. These findings are discussed in terms of tumor nutrition and vitamin B6 metabolism in a rat hepatoma cell line.
Authors:
N T Meisler; J W Thanassi
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Cancer research     Volume:  48     ISSN:  0008-5472     ISO Abbreviation:  Cancer Res.     Publication Date:  1988 Mar 
Date Detail:
Created Date:  1988-03-28     Completed Date:  1988-03-28     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  2984705R     Medline TA:  Cancer Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1080-5     Citation Subset:  IM    
Affiliation:
Department of Biochemistry, University of Vermont College of Medicine, Burlington 05405.
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MeSH Terms
Descriptor/Qualifier:
Animals
Liver / metabolism
Liver Neoplasms, Experimental / metabolism*
Pyridoxal Kinase / analysis
Pyridoxal Phosphate / analysis
Pyridoxaminephosphate Oxidase / analysis
Pyridoxine / metabolism*,  pharmacology
Rats
Tumor Cells, Cultured / metabolism
Grant Support
ID/Acronym/Agency:
35878//PHS HHS; 5429-25/16//PHS HHS
Chemical
Reg. No./Substance:
54-47-7/Pyridoxal Phosphate; 65-23-6/Pyridoxine; EC 1.4.3.5/Pyridoxaminephosphate Oxidase; EC 2.7.1.35/Pyridoxal Kinase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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