Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1993-9-30
pubmed:abstractText
Fluorescent calcium indicators have been widely used to assess cytoplasmic calcium concentration in cells. To examine the role of calcium ions on different physiological functions (e.g. in case of liver; bile secretion, glucose metabolism, etc.) there is a need for whole organ studies. We have developed a technique to estimate intracellular free calcium changes in perfused rat liver. Krebs-Henseleit perfused livers were loaded with 7 microM or 35 microM Indo-1/AM. An area 3 mm in diameter and approximately 300 microns in depth was illuminated at 340 nm. Fluorescence was monitored with photomultiplier tubes at 3 wavelengths (400 nm for Ca-bound dye, 504 nm for free dye and 464 nm for NADH). The viability of liver preparations was assessed by measurement of the concentrations of lactate dehydrogenase and alanine aminotransferase in the effluent. Loading of the livers with 7 microM Indo-1/AM via the portal vein resulted in a 5-fold increase of fluorescence at 400 nm. However the dye 'leaked' out of the liver with a half-time of 18 min. Probenecid (a specific anion carrier blocker) inhibited loss of dye in a dose dependent fashion (2.5-10 mM). Transient calcium elevations were observed in response to vasopressin (5-50 nM) at physiological levels, ethanol (0.3-0.8 M) and the calcium ionophore, ionomycin. Certain limitations were apparent with this approach: (1) it was necessary to use an anion carrier blocker to maintain a relatively steady dye concentration; (2) endogenous NADH fluorescence interfered with the calcium signal; and (3) absolute values of calcium concentration could not be determined.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0143-4160
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
465-72
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed-meshheading:8358770-Animals, pubmed-meshheading:8358770-Anion Transport Proteins, pubmed-meshheading:8358770-Artifacts, pubmed-meshheading:8358770-Calcium, pubmed-meshheading:8358770-Carrier Proteins, pubmed-meshheading:8358770-Cell Membrane Permeability, pubmed-meshheading:8358770-Ethanol, pubmed-meshheading:8358770-Fluorescent Dyes, pubmed-meshheading:8358770-Fluorometry, pubmed-meshheading:8358770-Indoles, pubmed-meshheading:8358770-Intracellular Fluid, pubmed-meshheading:8358770-Ionomycin, pubmed-meshheading:8358770-Liver, pubmed-meshheading:8358770-Male, pubmed-meshheading:8358770-NAD, pubmed-meshheading:8358770-Perfusion, pubmed-meshheading:8358770-Probenecid, pubmed-meshheading:8358770-Rats, pubmed-meshheading:8358770-Rats, Wistar, pubmed-meshheading:8358770-Sensitivity and Specificity, pubmed-meshheading:8358770-Vasopressins
pubmed:year
1993
pubmed:articleTitle
Monitoring of intracellular free calcium in perfused rat liver.
pubmed:affiliation
Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Rockville, Maryland.
pubmed:publicationType
Journal Article