Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-12-11
pubmed:abstractText
The present study was undertaken to characterize the export of cGMP from human erythrocytes at 37 degrees C. Inside-out membrane vesicles were exposed to cGMP and [3H]-cGMP in the presence and absence of 2 mmol l-1 ATP. In the absence of ATP, an equilibrium was reached within 15 min for the lowest tested concentration (0.65 mumol l-1), and the amount of cGMP in the vesicles was linearly correlated to the cGMP concentrations in the incubate. These observations suggest that the ATP-independent process represents passive diffusion or non-saturated binding to membrane components. In the presence of ATP, cGMP accumulated linearly during the test period (up to 120 min) and the transport into the inside-out vesicles was dependent on both low- and high-Km transport. The kinetic parameters for the low-Km process were determined after 5 and 120 min, the Km values being 4.6 (SD 1.9) and 4.7 (SD 1.1) mumol l-1 (n = 3), respectively. The corresponding Vmax values were 400 (SD 50) and 440 (SD 70) fmol mg-1 min-1. The high-Km process was characterized by Km = 170 (SD 50) mumol-1 and Vmax = 1610 (SD 280) fmol mg-1 min-1 (n = 5). The present data demonstrate an ATP-requiring saturable transport system for cGMP in human erythrocytes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0036-5513
pubmed:author
pubmed:issnType
Print
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
289-93
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Export of guanosine 3',5'-cyclic monophosphate (cGMP) from human erythrocytes characterized by inside-out membrane vesicles.
pubmed:affiliation
Department of Pharmacology, University of Tromsø, Norway.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't