The effects of methyl methacrylate monomer on testosterone level in male rats. An experimental study.

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.