Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1997-6-17
pubmed:abstractText
The increase in oral availability of felodipine and other commonly used medications when taken with grapefruit juice has been assumed to be due to inhibition of CYP3A4, a cytochrome P450 that is present in liver and intestine. To evaluate the effect of repeated grapefruit juice ingestion on CYP3A4 expression, 10 healthy men were given 8 oz of grapefruit juice three times a day for 6 d. Before and after receiving grapefruit juice, small bowel and colon mucosal biopsies were obtained endoscopically, oral felodipine kinetics were determined, and liver CYP3A4 activity was measured with the [14C N-methyl] erythromycin breath test in each subject. Grapefruit juice did not alter liver CYP3A4 activity, colon levels of CYP3A5, or small bowel concentrations of P-glycoprotein, villin, CYP1A1, and CYP2D6. In contrast, the concentration of CYP3A4 in small bowel epithelia (enterocytes) fell 62% (P = 0.0006) with no corresponding change in CYP3A4 mRNA levels. In addition, enterocyte concentrations of CYP3A4 measured before grapefruit juice consumption correlated with the increase in Cmax when felodipine was taken with either the 1st or the 16th glass of grapefruit juice relative to water (r = 0. 67, P = 0.043, and r = 0.71, P = 0.022, respectively). We conclude that a mechanism for the effect of grapefruit juice on oral felodipine kinetics is its selective downregulation of CYP3A4 in the small intestine.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-12959294, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-1309987, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-1347031, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-1430211, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-1544283, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-1602384, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-1671113, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-1683920, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-16867732, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2061924, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2265479, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2385232, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2440339, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2444983, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2732228, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2760845, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2784534, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2876781, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-2913056, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-3080674, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-3285175, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-3654968, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-3888267, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-3898085, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-3965334, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-4017422, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-6425105, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7586942, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7587952, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7619215, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-762169, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7628179, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7681059, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7734012, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7768070, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7894497, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7895614, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-7924120, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8035341, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8100494, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8373442, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8562295, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8612381, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8631189, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8689807, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8751023, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8855178, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-8971132, http://linkedlifedata.com/resource/pubmed/commentcorrection/9153299-9153265
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9738
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2545-53
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
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