Linked Life Data

2854534

Source:http://linkedlifedata.com/resource/pubmed/id/2854534

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1989-6-16
pubmed:abstractText
In ovarian follicles of Rana pipiens, frog pituitary homogenates (FPH) elevate intrafollicular progesterone levels which in turn is thought to induce meiotic resumption in the prophase I arrested oocytes. Calcium plays a role in FPH and steroid-provoked responses in the somatic and gametic components of the follicle, presumably via effects exerted at the plasma membrane of their respective target cells. Many membrane active hormones which utilize Ca2+ in their intracellular transduction also provoke membrane phosphoinositide hydrolysis yielding inositol triphosphate (IP3) and diacyl glycerol (DAG), an activator of the CA2+-dependent protein kinase C (PKC). The actions of phorbol 12-myristate 13-acetate (TPA), a potent synthetic activator of PKC, on progesterone production and oocyte maturation was examined in in vitro cultured ovarian follicles. TPA induced germinal vesicle breakdown (GVBD) in intact follicles and in oocytes denuded of somatic components, while the inactive compound phorbol 13-monoacetate was ineffective. Further, TPA induction of GVBD exhibited similarities to progesterone-induced GVBD, being inhibited by treatments which elevate cAMP or inhibit protein synthesis. TPA alone did not elevate intrafollicular or medium progesterone levels, as occurred in FPH-treated follicles. TPA partially inhibited intrafollicular progesterone accumulation induced by FPH or treatments which elevate cAMP levels. These data suggest that activation of PKC plays a role in oocyte maturation independent of follicular progesterone production as occurs in response to FPH. Further, it appears that the somatic cells of the amphibian follicle also possess PKC which when activated, antagonizes cAMP generating pathway in these cells. Results indicate that protein kinase can influence oocyte maturation in Rana follicular oocytes by several mechanisms.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0148-7280
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
323-34
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Role of protein kinase C activation in oocyte maturation and steroidogenesis in ovarian follicles of Rana pipiens: studies with phorbol 12-myristate 13-acetate.
pubmed:affiliation
Department of Population Dynamics, Johns Hopkins School of Hygiene, Baltimore, Maryland 21205.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't