Effects of Toluene and Formaldehyde on Oogenesis in Adult Female Mice

Background: The present study was designed to investigate the effects of toluene and formaldehyde inhalation on the ovaries of adult female mice at room temperature. Material & Methods: Mice were divided into three groups: control group, toluene exposed and formaldehyde exposed groups. The female mice were exposed to (3 ml = 300 ppm toluene) and (2.5 ml=300 ppm formaldehyde) 3 hours daily for 21 days. In this study a haemotoxlyin and eosin stains as well as the periodic acid Schiff (PAS) were used in order to illustrate the histological structures of the ovaries. Results: Female exposed to both solvents showed a significant decrease in their weights. Histological examination of the ovaries of the exposed mice (either to toluene or formaldehyde) revealed an increase in thickness of zona pellucida of ovarian follicles, significant increase in the number of primary, secondary and Graffian follicles with decrease in the number of primordial follicles after inhalation comparisons to the normal groups. Discussions: The results indicate that exposure to these organic solvents may suppress the central nervous system that contains vital centers which leads to reduction of mice weight. Conclusion: Both solvents may cause injuries to the ovaries followed by changes of the histological structure for them. This might be due to disruption of endocrine function which leads to suppression of the releasing of gonadotropins hormones