Methylglyoxal-bis(guanylhydrazone)-resistant Chinese hamster ovary cells: Genetic evidence that more than a single locus controls uptake
✍ Scribed by Mary Anne Heaton; Wayne F. Flintoff
- Publisher
- John Wiley and Sons
- Year
- 1988
- Tongue
- English
- Weight
- 709 KB
- Volume
- 136
- Category
- Article
- ISSN
- 0021-9541
No coin nor oath required. For personal study only.
✦ Synopsis
Chinese hamster ovary cells spontaneously resistant to the cytotoxic action of methylglyoxal-bis(guany1hydrazonc) have been isolated in a multistep selection scheme. A low-level resistant isolate has been shown to be defective in the ability to accumulate the drug intracellularly. This was reflected in a 10-fold lower V , , , than wild-type cells for drug uptake as well as a slight enhancement of drug efflux. More highly resistant isolates selected from this low-level resistant isolate were totally deficient in the ability to take up the drug. A partial revertant, selected from this low-level resistant isolate, retained some change in the V , , , for uptake but lost the accelerated rate of efflux characteristic of the low-level resistant line. Genetic analysis by somatic cell hybridization indicated that the low-level resistant phenotype was recessive to the wild-type phenotype. In addition, the low-level resistant phenotype could be complemented by a previously isolated highly resistant cell also defective in drug uptake (Mandel and Flintoff (1978) J. Cell. Physiol.,. Taken together, these data suggest that more than one locus controls drug uptake in Chinese hamster ovary cells.