title: Semiquantitation of intrahepatic MDR3 mRNA levels by reverse transcription/competitive polymerase chain reaction.
abstract: OBJECTIVE
  Knockout mice lacking mdr2, the murine analogue of human MDR3 P-glycoprotein, develop chronic non-suppurative cholangitis. Recently, a deficiency in MDR3 messenger RNA (mRNA) has been reported in a subtype of progressive familial intrahepatic cholestasis. Thus, reduced MDR3 gene expression could be involved in human cholestatic liver diseases.
  
  
  METHODS
  We developed a sensitive and specific reverse transcription/competitive polymerase chain reaction for the semiquantitation of intrahepatic MDR3 mRNA levels. Using this method we determined the MDR3 mRNA levels in 52 liver specimens from primary biliary cirrhosis (n=11), chronic hepatitis B (n=5), chronic hepatitis C (n=14), non-cholestatic cirrhosis (n=9) and controls (n=13).
  
  
  RESULTS
  MDR3 mRNA was detected in all specimens with some variation in mRNA levels. No significant differences in the mean MDR3 mRNA levels were present between the groups studied, including normal controls.
  
  
  CONCLUSIONS
  We found no evidence for deficient or severely reduced intrahepatic MDR3 mRNA in primary biliary cirrhosis, nor were mRNA levels altered significantly by virus-induced inflammation or by cirrhosis. The reverse transcription/competitive polymerase chain reaction assay described here should be a useful tool in the semiquantitative study of MDR3 mRNA levels in small tissue specimens.
authors.affiliation: Department of General Internal Medicine, University of Bonn, Germany. umm20d@ibm.rhrz.uni-bonn.de
authors.forename: F L
authors.initials: FL
authors.lastname: Dumoulin
authors.forename: C
authors.initials: C
authors.lastname: Reichel
authors.forename: T
authors.initials: T
authors.lastname: Sauerbruch
authors.forename: U
authors.initials: U
authors.lastname: Spengler
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D002908:Chronic Disease; D006509:Hepatitis B / Q000235:genetics; D006526:Hepatitis C / Q000235:genetics; D006801:Humans; D008099:Liver / Q000737:chemistry*; D008103:Liver Cirrhosis / Q000235:genetics; D008105:Liver Cirrhosis, Biliary / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D012333:RNA, Messenger / Q000032:analysis*; D012016:Reference Values; D014158:Transcription, Genetic
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D012333:RNA, Messenger; C095122:multidrug resistance protein 3