Linked Life Data

945685

Source:http://linkedlifedata.com/resource/pubmed/id/945685

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1976-9-1
pubmed:abstractText
The yolk sac of the little brown bat is unusual in that during the course of gestation both the inner endodermal cells (bordering the yolk sac cavity) and outer mesothelium (facing the exocelom) form simple columnar epithelia which persist throughout gestation. These endodermal cells develop an extensive system of agranular endoplasmic reticulum, numerous lipid droplets and unusual "giant" mitochondria. During development the Golgi apparatus changes position from the apical to the basal side of the nucleus, reversing the polarity of the cells. In general, the endodermal cells have cytological features suggestive of synthetic or secretory activity. The mesothelial cells develop an extensive "absorptive apparatus" in their apices, while large crystalloid-containing granules become numerous in their basal cytoplasm. The mesothelial cells have large deposits of glycogen, especially during mid-gestation, but few mitochondria and little granular endoplasmic reticulum. Endodermal cells do not absorb exogenous protein (peroxidase) even if it is injected directly into the yolk sac cavity. However, placement of peroxidase either in the exocelom or in the maternal vascular system results in the appearance of this protein in the "absorptive apparatus" of mesothelial cells as well as in macrophages in the stroma of the yolk sac. While evidence of absorption was clear, no direct evidence of transport of tracer to fetal blood vascular system was obtained. It is postulated that a major function of the hypertrophied mesothelial cells during gestation is the absorption of proteins and possibly other substances from the exocelomic fluid. The major function of the hypertrophied endodermal cells may be synthesis and secretion of substances into the fetal circulation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0002-9106
pubmed:author
pubmed:issnType
Print
pubmed:volume
146
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Cytological development of yolk sac endoderm and protein-absorptive mesothelium in the little brown bat, Myotis lucifugus.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.