Linked Life Data

1675832

Source:http://linkedlifedata.com/resource/pubmed/id/1675832

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1991-7-24
pubmed:abstractText
The characteristics of histamine H1-receptors expressed on astrocytes from the cerebral cortex of new born rats were analysed by the [3H]-mepyramine binding assay. The apparent dissociation constant (Kd) was 10.4 nM and the binding capacity (Bmax) of 262 fmol/mg protein. H1-antagonists inhibited the [3H]mepyramine bindings and the isomers of chlorpheniramine showed a stereoselectivity for the inhibition of the bindings. Two distinct populations of cultured astrocytes, type-1 and type-2 astrocytes, were enriched and histamine-induced accumulations of inositol phosphates (IP) and cyclic AMP and histamine-evoked Ca++ signals were examined. Histamine stimulated the accumulation of IP in type-2 astrocytes, but not in type-1 astrocytes. The accumulation of cyclic AMP induced by histamine was observed in type-1 astrocytes, although not in type-2 astrocytes. Histamine-induced Ca++ signals were observed in 17.2% of type-1 astrocytes and in 72.9% of type-2 astrocytes. Histamine-induced Ca++ signals in type-2 astrocytes were antagonized by H1-antagonists, but not by H2- antagonists. Histamine-induced Ca++ signals were classified into 4 patterns, ie. transient, oscillatory, sustained and biphasic. When extracellular Ca++ was omitted or La was added to the extracellular medium, sustained phase of Ca++ signal disappeared and transient and oscillatory patterns were only observed. Phorbol ester inhibited histamine-induced Ca++ signals but pertussis toxin (IAP) and organic voltage dependent Ca++ channel blockers had no effect. Histamine-induced Ca++ elevation appeared initially in processes and then Ca++ wave propagated to the cell soma. Ca++ elevation was observed only in the processes in some cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0379-0363
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
161-80
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Histamine H1-receptors on astrocytes in primary cultures: a possible target for histaminergic neurones.
pubmed:affiliation
Department of Pharmacology II, Faculty of Medicine, Osaka University, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't