Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-2-5
pubmed:abstractText
Alterations in intracellular cation concentrations in the kidney during hyperglycemia may play a role in a number of complications associated with diabetes mellitus such as renal hypertrophy and hypertension. In this study, we have investigated the effect of 25 mM glucose on intracellular pH and free Mg2+, free Ca2+, and Na+ concentrations in the perfused kidneys of Sprague-Dawley rats using 31P, 19F, and 23Na triple-quantum filtered NMR. No significant alteration occurred in the intracellular free Mg2+ concentration, pH, or ATP concentration during hyperglycemia. However, a sizable (approximately 50%) increase in the intracellular Na+ concentration was inferred from 23Na triple-quantum filtered NMR after 30-45 min of perfusion with 25 mM glucose. Intracellular free Ca2+, measured to be 390 +/- 15 nM at 5 mM glucose, increased significantly (95%; p < 0.001) to a value of 765 +/- 28 nM after 30 min of perfusion with 25 mM glucose. This effect of glucose was reversible. Only small increases (< or = 20%) in free Ca2+ were found with addition of comparable concentrations of a nontransportable sugar (20 mM mannitol), indicating that glucose entry into the cell (through the Na+/glucose cotransporter) plays a role in causing the free Ca2+ increase. No effect on free Ca2+ was however, seen with 1 mM ouabain, which caused a sizable increase in intracellular Na+, indicating that Na+/Ca2+ exchange does not play a significant role in the maintenance of low intracellular free Ca2+ in the kidney and that the observed increase in free Ca2+ is probably due to a decrease in the Ca2+/Mg(2+)-ATPase activity during hyperglycemia. Increased concentrations of Na+ and free Ca2+ during hyperglycemia may be involved in the mechanism of renal hypertrophy and hypertension, frequently associated with diabetes mellitus.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
991-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
NMR studies of the effect of hyperglycemia on intracellular cations in rat kidney.
pubmed:affiliation
Department of Physiology, Albert Einstein College of Medicine, Bronx, New York 10461.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.