Related Experiment Videos
Acute digoxin loading reduces ABCA8A mRNA expression in the mouse liver
Michi Wakaumi1, Kenichi Ishibashi, Hitoshi Ando
1Department of Pharmacology, Division of Clinical Pharmacology, Jichi Medical School, Kawachi, Tochigi, Japan.
Clinical and Experimental Pharmacology & Physiology
|February 1, 2006
Summary
Mouse ABCA8a, a transporter protein, showed reduced mRNA expression in the liver after digoxin exposure. This suggests ATP binding cassette (ABC) transporter ABCA8 plays a role in digoxin metabolism.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- The ATP binding cassette (ABC) transporter superfamily includes ABCA8, which transports lipophilic drugs like digoxin.
- Understanding the physiological roles of ABCA8 is crucial for drug metabolism studies.
Purpose of the Study:
- To clone and characterize a mouse homologue of human ABCA8, named ABCA8a.
- To investigate the effect of digoxin intoxication on ABCA8 mRNA expression in mice.
Main Methods:
- Cloning of mouse ABCA8a from a mouse heart cDNA library.
- Northern blotting and real-time quantitative polymerase chain reaction (qPCR) to analyze mRNA expression.
- Acute digoxin infusion model in mice.
Main Results:
- Mouse ABCA8a shares significant identity and expression patterns (liver, heart) with human ABCA8.
- Acute digoxin infusion significantly reduced ABCA8a mRNA levels in the liver (14.7% of vehicle control) 12-24 hours post-injection.
- Similar reductions were observed for ABCA5, ABCA7, ABCA8b, and ABCA9 mRNA, while digitoxin had no effect on ABCA8a mRNA.
Conclusions:
- ABCA8a is predominantly expressed in the mouse liver and heart, similar to its human counterpart.
- Digoxin exposure leads to a significant downregulation of ABCA8 mRNA in the liver.
- These findings suggest a potential role for ABCA8 in the hepatic metabolism of digoxin.