Linked Life Data

3445261

Source:http://linkedlifedata.com/resource/pubmed/id/3445261

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1988-5-3
pubmed:abstractText
Meiotic arrest of mammalian oocytes within ovarian follicles is maintained by a specific factor(s) within the follicle. There is strong evidence that cAMP plays an important role in the control of meiosis. Purines have also been implicated in the maintenance of meiotic arrest in vivo. Hypoxanthine and/or adenosine have been identified in pig and mouse follicular fluid and exert a meiosis-arresting action on mouse oocytes in culture. While adenosine apparently need not be metabolized to exert its action on oocyte maturation, the action of hypoxanthine is apparently due to the production of guanyl and/or xanthyl compounds by the oocyte-cumulus cell complex. The inosine monophosphate dehydrogenase inhibitors, mycophenolic acid and bredinin, induced maturation in cumulus cell-enclosed oocytes maintained in meiotic arrest by hypoxanthine. Hypoxanthine and adenosine are not toxic to oocytes, because oocytes undergo normal fertilization and pre- and post-implantation development following exposure to these molecules in vitro. It is not known how gonadotropins stimulate the resumption of meiosis within the follicle, but there are several possibilities: (1) the intrafollicular level of an oocyte maturation inhibitor is decreased; (2) the oocyte is uncoupled from surrounding follicle cells; (3) an inhibitory molecule is secreted or metabolized by the oocyte; and/or (4) a positive stimulus is produced by the follicle that overrides the presence of inhibitory molecules. Preliminary evidence suggests that cumulus cells may produce a positive stimulus that induces the maturation of cultured cumulus cell-enclosed oocytes. Whether germinal vesicle breakdown in vivo results from a positive induction, a loss of inhibitory input, or a combination of these two mechanisms remains to be determined.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0385-0005
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
463-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
The role of purines in the maintenance of meiotic arrest in mouse oocytes.
pubmed:affiliation
Jackson Laboratory, Bar Harbor, ME 04609.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't