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The effects of methyl methacrylate monomer on testosterone level in male rats. An experimental study
Jihad Fakhouri1, Georges Aftimos, George Hilal
1Saint-Joseph University, Department of Removable Prosthodontis, Faculty of Dental Medicine, Beirut, Lebanon. jihad.fakhouri@usj.edu.lb
Introduction:
Methyl methacrylate (MMA) is commonly used in medicine and dentistry. The adverse effects of MMA are well described in the literature. Animal studies have largely confirmed the risks reported in clinical observations. There is no study indicating direct implication of MMA on male fertility mechanism.
Objectives:
The purpose of this study was to determine whether MMA is able to modify the testosterone level.
Methods:
The target population consisted of 60 male Sprague-Dawley rats. They were closed in colony cages and divided into five groups: The first group (n=15) designated as the control group and four experimental groups (n=45). Experiments were conducted by exposing the four experimental groups to MMA with water at different concentrations (4% per hundred, 8% per hundred, 16% per hundred and 32% per hundred) administered per os. The exposure duration was eight months. Blood was obtained before and at the end of the exposure and the measurement of the testosterone level was made by EIA test.
Results:
The exposure of rats at a moderate concentration of MMA (16% per hundred) showed an increase in testosterone level of 60% (p = 0.003) while the other groups showed a decrease of testosterone level. The control group showed a decrease of 44.8% (p = 0.001), the rats exposed at 4% per hundred showed a decrease of 67.7% (p = 0.000), those exposed at 8% per hundred showed a decrease of 432% (p = 0.35), the rats exposed at 32% per hundred showed a decrease of 71.7% (p = 0.002).
Conclusion:
Despite the fact that MMA at low concentration was rapidly hydrolyzed in blood due to the nonspecific carboxylesterase and metabolized at high concentration by the liver, its effects on testosterone level were significant. These preliminary results showed an interference of the MMA with the testosterone hormonal equilibrium that could be an interesting target for further investigations.
Insights
Methyl methacrylate (MMA) exposure in rats significantly altered testosterone levels. Moderate MMA concentrations increased testosterone, while other concentrations and control groups showed decreases, suggesting hormonal interference.
Area of Science:
- Endocrinology
- Toxicology
- Reproductive Biology
Background:
- Methyl methacrylate (MMA) is widely used in medical and dental applications.
- While MMA's adverse effects are documented, its impact on male fertility mechanisms remains unstudied.
- Existing literature lacks data on MMA's direct implications for male reproductive health.
Purpose of the Study:
- To investigate the potential effects of methyl methacrylate (MMA) on male reproductive hormone levels.
- To determine if MMA exposure can alter serum testosterone concentrations in a rodent model.
- To assess the dose-dependent relationship between MMA exposure and testosterone level modification.
Main Methods:
- Sixty male Sprague-Dawley rats were divided into five groups: one control and four experimental groups exposed to varying MMA concentrations (4%, 8%, 16%, 32%) in water.
- Oral administration of MMA was conducted over an eight-month exposure period.
- Serum testosterone levels were measured using Enzyme Immunoassay (EIA) before and after the exposure period.
Main Results:
- Exposure to 16% MMA resulted in a significant 60% increase in testosterone levels (p=0.003).
- Conversely, other MMA concentrations and the control group exhibited decreased testosterone levels, ranging from 44.8% to 71.7%.
- A notable decrease of 432% was observed in the 8% MMA group, though not statistically significant (p=0.35).
Conclusions:
- Methyl methacrylate (MMA) significantly interferes with testosterone hormonal equilibrium in male rats.
- Metabolism of MMA occurs via hydrolysis and liver processing, but hormonal effects persist.
- These findings highlight MMA as a potential endocrine disruptor warranting further investigation into its reproductive toxicity.