**2. Methods**

In these series of experiments the Wistar rats are used as an experimental model and the studies were approved by the ethical committee of Tabriz University of Medical Sciences. For producing EMF, an EMF generating apparatus was designed in the Department of the Histology and Emberyology. The apparatus uses 220 V and 50 HZ alternative current and could generate up to 5 milli tesla EMF. In the presented studies, the adult female rats were exposed to 3 milli tesla, 4 hours/day for 2 months. After the experimental period the rats were sacrificed and their reproductive organs including; ovaries, uteri, and uterine tubes were dissected apart. Half of the samples were fixed in 10% formalin and paraffinembedded sections were used for light microscopy and immunohistochemical studies. TUNEL techniques were used for detection of apoptosis and Ki-67 technique for proliferation assay. In both cases toluidine blue was used for counterstaining.

The other half of the samples were fixed in 2% glutaraldehyde and resin embedded ultra thin sections were used for electron microscopy.

#### **3. Results**

#### **3.1 Ovarian effect of EMF exposure**

Ovary is an organ involved in follicular development and germ cell production. In other word, the ovary provides a proper environment for oogenesis. Any disturbances in ovarian function may lead to the folliculogenesis disorder and or ceasing of ovulation. Several factors including hormonal disturbances, changes in ovarian stroma and or any factor that affect oocyte maturation would affect oogenesis.
