Display Settings:

Format

Send to:

Choose Destination
    Eur J Pharmacol. 2003 Jan 24;460(2-3):85-91.

    MDR1-deficient genotype in Collie dogs hypersensitive to the P-glycoprotein substrate ivermectin.

    Source

    Laboratoire de Pharmacologie et Toxicologie, INRA-180 Chemin de Tournefeuille, BP 3, 31931 Toulouse Cedex 9, France.

    Abstract

    Multidrug resistance (MDR) phenotypes in cancer cells are associated with overexpression of the drug carrier P-glycoprotein. The antiparasitic drug ivermectin, one of its substrates, abnormally accumulates in the brain of transgenic mice lacking the P-glycoprotein, resulting in neurotoxicity. Similarly, an enhanced sensitivity to ivermectin has been reported in certain dogs of the Collie breed. To explore the basis of this phenotype, we analyzed the canine P-glycoprotein-encoding MDR1 gene, and we report the first characterization of the cDNA for wild-type (Beagle) P-glycoprotein. The corresponding transcripts from ivermectin-sensitive Collies revealed a homozygous 4-bp exonic deletion. We established, by genetic testings, that the MDR1 frame shift is predictable. Accordingly, no P-glycoprotein was detected in the homozygote-deficient dogs. In conclusion, we characterized a unique case of naturally occurring gene invalidation. This provides a putative novel model that remains to be exploited in the field of human therapeutics and that might significantly affect tissue distribution and drug bioavailability studies.

    PMID:
    12559367
    [PubMed - indexed for MEDLINE]

      Supplemental Content

      Icon for Elsevier Science

      Save items

      loading

      Recent activity

      Your browsing activity is empty.

      Activity recording is turned off.

      Turn recording back on

      See more...
      Write to the Help Desk