Linked Life Data

6403084

Source:http://linkedlifedata.com/resource/pubmed/id/6403084

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1983-5-27
pubmed:abstractText
Megakaryocytes share a number of structural and chemical properties with their progeny, blood platelets. With the availability of highly purified preparations of megakaryocytes isolated from guinea pig bone marrow, it is now also possible to study functional aspects of these cells. The present work reports the first study of the release of endogenously stored materials in megakaryocytes. Guinea pig megakaryocytes isolated to 75%-90% purity were exposed to thrombin or calcium ionophore (A23187) and the release of ATP was continuously monitored with the luciferin-luciferase reaction. Both maximal extent and initial rate of release were studied. Thrombin-induced release was half-maximal at thrombin concentrations of 0.2-0.5 NIH U/ml. At 4 U/ml thrombin, maximal release was 538 +/- 147 nmole ATP/10(9) megakaryocytes. A23187 induced half-maximal responses at concentrations of 7-8 microM. ATP release by ionophore showed a nearly absolute requirement for extracellular calcium, with release by thrombin showing only a partial calcium dependence. Following overnight culture, the response to thrombin was unchanged, whereas ATP release in response to ionophore was consistently increased (p less than 0.01). By comparison of maximally releasable ATP with total cellular ATP content, the storage pool of ATP in megakaryocytes was determined to comprise only 2%-6% of total megakaryocyte ATP, in contrast to an ATP storage pool of 20%-30% in guinea pig platelets. This difference may reflect further entry of ATP into the storage pool compartment or an enhanced ability of the cell to recognize and respond fully to platelet stimuli as the megakaryocyte reaches full maturity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:volume
61
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
967-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Characterization of the megakaryocyte secretory response: studies of continuously monitored release of endogenous ATP.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't