Related Experiment Video
Updated: Aug 11, 2026

10:31
An Experimental Model of Diet-Induced Metabolic Syndrome in Rabbit: Methodological Considerations, Development, and Assessment
Published on: April 20, 2018
Methandrostenolone: metabolism in the rabbit
Summary
Researchers identified new methandrostenolone metabolites in rabbit urine, including previously unreported C-16 hydroxylated and dihydroxylated compounds. This study enhances understanding of anabolic steroid metabolism in vivo.
Area of Science:
- Pharmacology
- Metabolomics
- Analytical Chemistry
Background:
- Methandrostenolone is an anabolic-androgenic steroid with performance-enhancing properties.
- Understanding its metabolic pathways is crucial for doping control and toxicological assessment.
- Previous studies have identified various methandrostenolone metabolites, but comprehensive analysis remains ongoing.
Purpose of the Study:
- To identify and characterize novel methandrostenolone metabolites in rabbit urine.
- To investigate the metabolic fate of methandrostenolone following oral administration in rabbits.
- To report previously undocumented hydroxylated metabolites.
Main Methods:
- Oral administration of methandrostenolone to rabbits.
- Urine sample collection and processing.
- Isolation and identification of metabolites using advanced analytical techniques (e.g., chromatography and mass spectrometry).
Main Results:
- Several methandrostenolone metabolites were successfully isolated and identified.
- New C-16 hydroxylated and dihydroxylated metabolites were discovered.
- Fully reduced, partially reduced, monohydroxylated, and dihydroxylated metabolites were characterized.
- No epimerization at the C-17 position was observed in the rabbit model.
Conclusions:
- The rabbit model exhibits a unique metabolic profile for methandrostenolone, including novel C-16 modifications.
- The findings expand the known spectrum of methandrostenolone metabolites.
- This research contributes to a more comprehensive understanding of methandrostenolone metabolism and aids in the detection of its use.
Related Concept Videos
Drug Metabolism: Phase I Reactions
A phase I reaction is a biochemical process that introduces a functionally reactive polar group to a substance. This transformation predominantly occurs in the liver, facilitated by the cytochrome P450 system of hemoproteins situated in the lipophilic endoplasmic reticulum of cells. The metabolite generated through this process can have varying polarities. If it is sufficiently polar, it can be easily excreted in the urine due to its water compatibility. However, if the metabolite is nonpolar,...
Drug Metabolism: Phase II Reactions
Phase II reactions are essential for the detoxification and elimination of drugs from the body. These reactions involve the conjugation of parent drugs or their phase I metabolites with endogenous molecules, resulting in more hydrophilic drug conjugates. The primary conjugation reactions in this phase are sulfation and glucuronidation. Both sulfation and glucuronidation typically produce biologically inactive metabolites. However, in some cases involving prodrugs, active metabolites may be...
Drug Biotransformation: Overview
Biotransformation, also known as drug metabolism, is a vital physiological process that chemically alters drugs, facilitating their elimination from the body and terminating their action. This process involves two main phases: phase I and phase II reactions. Phase I reactions, including oxidation, reduction, and hydrolysis, introduce or unmask polar functional groups on the drug molecule, thereby increasing its water solubility. By enhancing water solubility, the drug becomes more hydrophilic...
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Metabolism
Geriatric patients show significant variation in how their bodies process medications, which can change how effective and safe treatments are. The liver is the primary organ where drug metabolism occurs, involving two main types of chemical reactions: phase I and II. Phase I metabolism is driven by the cytochrome P450 enzyme system, which includes key types such as CYP3A, CYP2D6, and CYP2C9. Research indicates that while aging doesn't notably alter the levels or activity of these enzymes, it...
Pharmacokinetics in Obese Patients: Drug Metabolism and Excretion
Drug metabolism, a critical process in the liver, involves two primary phases: Phase I reactions and Phase II conjugation. Obesity introduces significant alterations in this metabolic process, primarily due to fatty infiltration of the liver, leading to conditions such as nonalcoholic fatty liver disease (NAFLD). This condition can modify the activities of both Phase I and II enzymes, impacting how drugs are metabolized in obese patients.Phase I metabolism sees variable effects across...

