| First Author | Tsuruoka S | Year | 2001 |
| Journal | J Am Soc Nephrol | Volume | 12 |
| Issue | 1 | Pages | 177-81 |
| PubMed ID | 11134265 | Mgi Jnum | J:76985 |
| Mgi Id | MGI:2180724 | Doi | 10.1681/ASN.V121177 |
| Citation | Tsuruoka S, et al. (2001) P-glycoprotein-mediated drug secretion in mouse proximal tubule perfused in vitro. J Am Soc Nephrol 12(1):177-81 |
| abstractText | To examine the functional significance of drug-transporting P-glycoprotein (P-gp), studies were conducted in the isolated and perfused proximal tubule S2 segment from mice disrupting both mdr1a and mdr1b genes [mdr1a/1b(-)(-)] and their wild-type mice. Efflux of the intracellular fluorescence of rhodamine 123, a fluorescence substrate of P-gp, into the lumen was measured, and the decay half-time of the intracellular fluorescence (T(1/2)) as an index of the drug-transporting P-gp activity was regarded. In the wild-type mice, the T(1/2) was 34 +/- 4 s (n = 36) at the basal period and was increased to 434 +/- 41 s by the addition of luminal verapamil, a P-gp inhibitor. In the mdr1a/1b(-)(-) mice, the T(1/2) was 407 +/- 16 s (n = 10) at the basal period and was no longer affected by the luminal addition of verapamil. The digoxin content in the kidney after a repeated administration of the drug was markedly elevated in the mdr1a/1b(-)(-) mice. In conclusion, P-gp-mediated drug efflux capacity indeed exists in the apical membrane of proximal tubule cells from the wild-type mice, whereas it is absent in that of the mdr1a/1b(-)(-) mice. |
