Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2010-9-21
pubmed:abstractText
Nitrite-hemoglobin reactions have been studied extensively in vitro, but there is a lack of information on the kinetics of nitrite and its metabolites in humans. In this study, we developed a nine-compartment physiological pharmacokinetic model to describe the in vivo erythrocytic uptake and release and disposition pathways of nitrite, nitrate, methemoglobin, and iron-nitrosyl hemoglobin in the human circulation. Our model revealed that nitrite entered erythrocytes rapidly with a rate constant of 0.256 min(-1) (i.e., half-life = 2.71 min). The formation of iron-nitrosyl hemoglobin from nitrite, which involves the reduction of nitrite by deoxyhemoglobin to generate nitric oxide (NO) and reaction of NO with deoxyhemoglobin to form iron-nitrosyl hemoglobin, occurred rapidly as well (k = 2.02 min(-1); half-life = 0.343 min = 21 s). The disposition kinetics of methemoglobin was complex. Nitrate formation occurred primarily in erythrocytes through the nitrite-oxyhemoglobin reaction and was higher when nitrite was administered intra-arterially than intravenously. Nitrate reduction was an insignificant metabolic pathway. This study is the first to comprehensively evaluate the kinetics of nitrite and its metabolites in humans and provides unique insights into the rapid equilibrium of nitrite into erythrocytes and conversion to NO in the red cell, which is kinetically associated with vasodilation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1521-009X
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1707-13
pubmed:dateRevised
2011-10-19
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Characterization of erythrocytic uptake and release and disposition pathways of nitrite, nitrate, methemoglobin, and iron-nitrosyl hemoglobin in the human circulation.
pubmed:affiliation
Clinical Center Pharmacy Department, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA. chon@cc.nih.gov
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, N.I.H., Intramural