Document Detail

Kinetic and pharmacological properties of [(3)H]-histamine transport into cultured type 1 astrocytes from neonatal rats.
MedLine Citation:
PMID:  19184360     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE AND DESIGN: Astrocytes actively participate in the inactivation of neurotransmitters. In this work we elucidated the contribution of astrocytes in clearance of histamine, a process which has not yet been fully clarified. METHODS: The characteristics of [(3)H]-histamine uptake were determined in cultured neonatal rat type 1 astrocytes and histamine-N-methyl-transferase expression was determined using RT-PCR. RESULTS: These cells transport [(3)H]-histamine in a time- and concentration-dependent manner. The histamine clearance by astrocytes was described by a mathematical model including two processes: electrodiffusion and active transport. A further analysis of kinetic parameters of a carrier-operated transport revealed a single transport system with Michaelis constant (K(m)) of 3.5 +/- 0.8 microM and a maximal uptake rate (V(max)) of 7.9 +/- 0.3 pmol/mg protein/min. From drugs tested amitriptyline, desipramine, mepyramine and cimetidine significantly decreased [(3)H]-histamine uptake. Taken-up histamine could be metabolically degraded in cultured astrocytes, since they express mRNA for enzyme histamine-N-methyltransferase. CONCLUSIONS: Astrocytes participate in the clearance of extracellular histamine by electrodiffusion and active transport by a yet not identified carrier. Taken up histamine can be converted to tele-methylhistamine within astrocytes thus indicating the involvement of astrocytes not only in clearance but also in the inactivation of histamine.
D Osredkar; T Burnik-Papler; B Pecavar; V Kralj-Iglic; M Krzan
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Inflammation research : official journal of the European Histamine Research Society ... [et al.]     Volume:  58     ISSN:  1420-908X     ISO Abbreviation:  Inflamm. Res.     Publication Date:  2009 Feb 
Date Detail:
Created Date:  2009-02-02     Completed Date:  2009-04-14     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9508160     Medline TA:  Inflamm Res     Country:  Switzerland    
Other Details:
Languages:  eng     Pagination:  94-102     Citation Subset:  IM    
Department of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
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MeSH Terms
Animals, Newborn
Antidepressive Agents / pharmacology
Astrocytes / cytology,  metabolism*
Biological Transport / drug effects,  physiology
Cell Membrane / metabolism
Cells, Cultured
Histamine / chemistry,  metabolism*
Histamine Antagonists / metabolism
Histamine N-Methyltransferase / metabolism
Models, Theoretical
Receptors, Histamine / metabolism
Tritium / chemistry,  metabolism*
Reg. No./Substance:
0/Antidepressive Agents; 0/Histamine Antagonists; 0/Receptors, Histamine; 10028-17-8/Tritium; 51-45-6/Histamine; EC N-Methyltransferase

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