What does microsomal ethanol oxidizing system do?
The microsomal ethanol oxidizing system (particularly the enzyme P-450 2E-1) is highly inducible by alcohol and promotes the conversion of alcohol to acetaldehyde.
What triggers the MEOS pathway?
Heavy drinking stimulates the human body to include the MEOS system enzymes to clear ethanol faster from the body. The MEOS system is also located in the liver. Similar to the Alcohol dehydrogenase system, acetaldehyde dehydrogenase will immediately convert acetaldehyde into acetate, a non-toxic molecule.
What is MEOS pathway?
The MEOS (microsomal ethanol oxidizing system) is an accessory pathway in the liver which increases in activity on chronic alcohol induction. The MEOS utilizes a cytochrome P450 which has since been deciphered to be CYP2E1, an ethanol-inducible form of P450.
Is alcohol metabolized via the microsomal P450?
Once ingested, most of the alcohol is metabolized in the liver by alcohol dehydrogenase to acetaldehyde. Two additional pathways of acetaldehyde generation are by microsomal ethanol oxidizing system (cytochrome P450 2E1) and catalase.
What is microsomal oxidation?
The microsomal ethanol oxidizing system (MEOS) is an alternate pathway of ethanol metabolism that occurs in the smooth endoplasmic reticulum in the oxidation of ethanol to acetaldehyde. In this reaction, ethanol is oxidized (losing two hydrogens) and O2 is reduced (by accepting hydrogen) to form H2O.
Where does microsomal ethanol oxidizing system occur?
The microsomal ethanol oxidizing system (MEOS) is an alternate pathway of ethanol metabolism that occurs in the smooth endoplasmic reticulum in the oxidation of ethanol to acetaldehyde.
What are the microsomal enzymes?
There are several microsomal enzymes, including flavin monooxygenases, cytochrome P450, NADPH cytochrome c reductase, UDP Glucoronosyl transferases (UGT), glutathione-S-transferases, epoxide hydrolases, etc. Cytochrome P450 and NADPH cytochrome c reductase are the two main enzymes in this system.
What is microsomal induction?
Microsomal enzyme inducing drugs such as phenytoin, phenobarbital and carbamazepine, and also alcohol, influence serum lipid and apoprotein concentrations. The inducers increase the concentrations of hepatic microsomal enzyme and apo A-I mRNA, and also proteins and phospholipids.
What is the function of microsomal enzymes?
Inducers of microsomal enzymes stimulate the metabolism or synthesis of several normal body substrates such as steroid hormones, pyridine nucleotides, cytochromes, and bilirubin. Evidence has accumulated that steroids are normal body substrates of drug-metabolizing enzymes in liver microsomes.