Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
4 Pt 2
|
pubmed:dateCreated |
1996-12-4
|
pubmed:abstractText |
Intracellular AMP hydrolysis probably produces sufficient adenosine in ischemic heart to exert physiological activity. Because data on adenosine-producing systems in human heart are scarce, we measured 1) formation of adenosine (catabolites) in ischemic human heart slices and 2) cytoplasmic 5'-nucleotidase activity in human left ventricle. We also measured the latter in rat ventricle and cardiomyocytes. During the first 5 min of incubation, adenosine production in slices (n = 5) equaled 26 +/- 10 (SD) nmol.min-1.g wet wt-1, and total AMP content was 0.81 +/- 0.46 mM. Cytoplasmic IMP-preferring 5'-nucleotidase activity in homogenates of human heart (N-II, 167 +/- 78 mU/g, n = 23) was significantly higher than that of the AMP-preferring one (N-I, 107 +/- 61 mU/g, n = 24). Both isozymes were two to three times more active in rat heart than in human heart. Rat cardiomyocytes contained comparable amounts of the two 5'-nucleotidases. Kinetics of N-I isolated from explanted human heart displayed features similar to the enzyme from animal heart, with a Michaelis constant of 1.5 mM under maximally stimulated conditions. This form can provide the amount of adenosine found in ischemic slices. In conclusion, human heart shows lower cytosolic 5'-nucleotidase activities than rat heart. Nevertheless, cytosolic 5'-nucleotidase activity in human heart can easily account for adenosine formation during ischemia.
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/5'-Nucleotidase,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Diphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Isoenzymes,
http://linkedlifedata.com/resource/pubmed/chemical/adenosine 5'-methylenediphosphate
|
pubmed:status |
MEDLINE
|
pubmed:month |
Apr
|
pubmed:issn |
0002-9513
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
270
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
H1493-500
|
pubmed:dateRevised |
2006-11-15
|
pubmed:meshHeading |
pubmed-meshheading:8967393-5'-Nucleotidase,
pubmed-meshheading:8967393-Adenosine Diphosphate,
pubmed-meshheading:8967393-Adenosine Triphosphate,
pubmed-meshheading:8967393-Animals,
pubmed-meshheading:8967393-Cytosol,
pubmed-meshheading:8967393-Heart Ventricles,
pubmed-meshheading:8967393-Humans,
pubmed-meshheading:8967393-Isoenzymes,
pubmed-meshheading:8967393-Myocardium,
pubmed-meshheading:8967393-Rats,
pubmed-meshheading:8967393-Solubility
|
pubmed:year |
1996
|
pubmed:articleTitle |
Soluble forms of 5'-nucleotidase in rat and human heart.
|
pubmed:affiliation |
Department of Biochemistry, Medical University of Gdansk, Poland. acskl@amedec.amg.gda.pl
|
pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
|