Multiple drug resistance
Multiple Drug Resistance , also called Multi Drug Resistance ( MDR ), describes the phenomenon that cells (e.g. tumor cells , tuberculosis pathogens ) have or develop resistance to drugs. Transporters that push these substances / drugs out of the cell can be responsible for this.
The best known is the transporter MDR1 ( Multidrug Resistance Protein 1 ): the glycoprotein with a mass of 170 kDa became known as P170 or P-glycoprotein and is the first of 49 ABC transporters that have been characterized in humans . The original function of MDR1 is assumed to be the detoxification of the organism from exogenous substances.
The MDR1 defect is a genetic defect that occurs in Collies and related breeds. The inheritance is recessive . If a dog is affected by the MDR1 defect, multidrug resistance protein 1 is no longer produced and the dog can even die from certain medicinal substances. This phenomenon has been known for a long time under the term "Ivermectin-sensitive Collie", but affects a lot more active ingredients.
Other active transport systems responsible for Multiple Drug Resistance are the Multidrug Resistance-Related Proteins (MRP).