Linked Life Data

6733770

Source:http://linkedlifedata.com/resource/pubmed/id/6733770

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1984-7-27
pubmed:abstractText
In model experiments with the use of horseradish peroxidase (HRP), two pathways of transport of substances to the adenohypophysis were studied, as well as the distribution of the tracer in the latter organ. The first pathway allows the tracer to penetrate from the intercellular milieu of the median eminence below the meningeal sheath covering the adenohypophysis to the surface of the pituitary gland. The second pathway transports the tracer via the capillaries of the hypophysial portal circulation to the interior of the glandular parenchyma. These results show (i) that the meningeal sheath establishes a barrier between the hemal milieu of the pituitary and the hemal milieu of the general circulation, and (ii) that the tracer reaching the adenohypophysis via both routes is found in the intercellular clefts of the glandular parenchyma only to a limited extent. By means of conventional electron microscopy, intercellular contacts between hormone-producing adenohypophysial cells are observed resembling focal tight junctions. Between the membranes of entwined processes of stellate cells, only small maculae adhaerentes are found. Freeze-etch studies on unfixed adenohypophyses reveal zonulae occludentes between the durafacing layers of the meningeal sheath and focal maculae occludentes between parenchymal cells. Additional tissue-culture experiments with adenohypophysial cells directly exposed to HRP reveal a gradual cessation of the labeling process in the intercellular clefts in accord with the observations from the in-vivo experiments, as well as intercellular focal tight junctions between individual hormone-producing cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0302-766X
pubmed:author
pubmed:issnType
Print
pubmed:volume
236
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
439-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Access and distribution of exogenous substances in the intercellular clefts of the rat adenohypophysis.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't