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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-3-12
pubmed:abstractText
The uptake of the catamphiphilic drugs flunarizine, R 56865 [N-1-4-(4-fluorophenoxy)butyl-4-piperidinyl-N-methyl-2- benzothiazolamine], verapamil, diltiazem, lidocaine and the noncatamphiphilic drug nitrendipine into erythrocytes and erythrocyte membranes was measured at pH 7.2 in a Ringer's solution at 22 degrees C. The uptake was concentration proportional between 10(-8) and 10(-6) mol/l for all drugs investigated; the erythrocyte/medium ratio (E/M) was constant after 20 min in all experiments. In rat aortas and left atria drug uptake was measured in a 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid buffered medium (pH 7.2, 32 degrees C). Equilibrium was reached after 360 min and the tissue/medium ratio (T/M) was concentration proportional between 10(-8) and 10(-6) mol/l for all drugs. E/M or T/M ratios, respectively, increased in the order: erythrocytes less than aortas less than left atria. However, the particular drug/phospholipid ratios were relatively constant for the drugs investigated, indicating that the membranes were a major distribution phase for these drugs. For the catamphiphilic drugs, the E/M or T/M ratios correlated linearly with the EC50 for 45Ca displacement from phosphatidylserine monolayers, but were poorly correlated with the octanol-water coefficient of the unchanged molecules. The EC50 for 45Ca displacement from phosphatidylserine monolayers is a measure for the uptake of the protonated species of catamphiphilic drugs into erythrocytes or tissue and may be a good estimate of tissue uptake of these drugs in general.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
252
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
333-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Uptake of catamphiphilic drugs into erythrocytes and muscular tissue correlates to membrane enrichment and to 45Ca displacement from phosphatidylserine monolayers.
pubmed:affiliation
Janssen Research Foundation, Neuss, FRG.
pubmed:publicationType
Journal Article, In Vitro