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

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. The purpose of this study was to determine whether MMA is able to modify the testosterone level. 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%, 8%, 16% and 32%] 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. The exposure of rats at a moderate concentration of MMA [16%] 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% showed a decrease of 67.7% [p = 0.000], those exposed at 8% showed a decrease of 4.32% [p = 0.35], the rats exposed at 32% showed a decrease of 71.7% [p = 0.002]. 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

Toxic effects of methyl methacrylate monomer on male genital tissue in vitro study in rats

Methyl methacrylate [MMA], a widely used monomer in dentistry and medicine has been reported to cause abnormalities or lesions in several organs. Experimental and clinical studies have documented that monomers may cause a wide range of adverse health effects such as irritation to skin, eyes, and mucous membranes, allergic dermatitis, stomatitis, asthma, neuropathy, disturbances of the central nervous system, liver toxicity, and fertility disturbances. The purpose of this study was to determine whether MMA mixed with water at four different concentrations is able to affect the histological structure of testicular tissues and seminal vesicle on male rats. The target population consisted of 60 male Sprague-Dawley rats. They were housed 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 administered per os mixed with water at different concentrations [4%, 8%, 16%, 32%]. The exposure duration was eight months. The testicles and the seminal vesicles were then extracted, dissected, fixed in Bouin liquid fixative and were submitted to the pathology laboratory [National Institute of Pathology] for histopathological examination. Seven out of 10 rats to which the MMA was administrated at a concentration of 32% showed partial seminal vesicle atrophy. The seminal vesicles in the remaining rats showed normal histology in all specimens. Testis, epididymis and vas deferens showed normal histology in all rats. The data in this study showed that MMA administered at high concentration is associated to seminal vesicle atrophy. These findings let us suggest that this effect could be the result of either a direct effect of MMA on testosterone levels [as shown in our first study], or through its possible action on other organs involved in testosterone metabolism and seminal vesicle trophicity such as the hypophysis