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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-9-8
pubmed:abstractText
Recent studies have shown the gene expression of several transporters to be circadian rhythmic. However, it remains to be elucidated whether the expression of P-glycoprotein, which is involved in the transport of many medications, undergoes 24 h rhythmicity. To address this issue, we investigated daily profiles of P-glycoprotein mRNA and protein levels in peripheral mouse tissues. In the liver and intestine, but not in the kidney, Abcb1a mRNA expression showed clear 24 h rhythmicity. On the other hand, Abcb1b and Abcb4, the other P-glycoprotein genes, did not exhibit significant rhythmic expression in the studied tissues. In the intestine, levels of whole P-glycoprotein also exhibited a daily rhythm, with a peak occurring in the latter half of the light phase and a trough at the onset of the light phase. Consistent with the day-night change of P-glycoprotein level, the ex vivo accumulation of digoxin, an Abcb1a P-glycoprotein substrate, into the intestinal segments at the onset of dark phase was significantly lower than it was at the onset of the light phase. Thus, Abcb1a P-glycoprotein expression, and apparently its function, are 24 h rhythmic at least in mouse intestine tissue. This circadian variation might be involved in various chronopharmacological phenomena.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0742-0528
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
655-65
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Daily rhythms of P-glycoprotein expression in mice.
pubmed:affiliation
Division of Clinical Pharmacology, Department of Pharmacology, Jichi Medical School, Minami-kawachi, Tochigi, Japan.
pubmed:publicationType
Journal Article